Physios’ views on goal-setting for people with COPD

We set up a qualitative study to explore respiratory physiotherapists’ views of goals, and their experiences of goal-setting, with people with chronic obstructive pulmonary disease (COPD). We conducted face-to-face interviews with 17 physiotherapists, which were audio-recorded for subsequent transcription and detailed analysis. Most of the physios worked with patients with COPD in pulmonary rehabilitation (some combining this with acute care), or in community settings.

The full paper can be accessed here. These are the edited highlights.

Key messages

  • Goal-setting in relation to COPD is challenging for respiratory physiotherapists.
  • There is considerable uncertainty among physios as to how goal-setting should best be approached.
  • Goal-setting can be driven by service needs, rather than patient needs. This creates tensions for clinicians who have a duty to fulfil both.
  • Clinicians need time and resources to undertake meaningful goal-setting, and may need additional postgraduate training to help them resolve some of these issues.

Three main themes emerged from our data analysis:

  • Theme 1: ‘Explaining goal-setting’ describes how goals were understood by physios, and their perceived purpose and value in respiratory rehabilitation.
  • Theme 2: ‘Working with goals’ explores physios’ accounts of working with goals (or not), and the practicalities associated with collaborative goal-setting.
  • Theme 3: ‘Influences on collaborative goal-setting’ highlights factors perceived by physios to be facilitating or hindering collaborative goal-setting.

Theme 1 – Explaining goal-setting

Definitions of goals  Goals were perceived as desirable achievements. Most stated goals should be personally meaningful to the individual patient, and identified from the outset. Aspects of the mnemonic SMART (Specific, Measurable, Achievable, Realistic and Timed) featured heavily. SMART goals were perceived as desirable properties of a goal, but could not always be attained:

‘I think “what am I trying to achieve with them?” I think that’s what a goal is. It’s what ultimately you’re trying to achieve. And the goal has to be something that’s relevant to the patient.’ (Emma, Band 7, Community)

Bernice associated goals specifically with aspirational undertakings (like mountain climbing):

‘Functional things, like walking or stair climbing, rather than their goal might be to climb Mount Everest er, do you know what I mean? I find it quite difficult really to put a goal to something that’s just a general practical improvement really’ (Bernice, Band 8, Acute and pulmonary rehabilitation)

And Lisa was unsure as to how to define goals:

‘I think if you think of a goal as something that facilitates behaviour change then that’s why it’s different from an outcome.  An outcome is the end result of doing your goals really, in a way.  Or using, I suppose a goal is working towards an outcome.  I’d.. yeah.. I think it’s really tricky I don’t think I really know.  I’m not sure it’s that clear’ (Lisa, Band 8, pulmonary rehabilitation)

Types of goals  These physios reported setting a variety of goals with patients, which could be considered as falling into one of four broad ‘types’; a) Aspirational, b) Functional, c) Condition understanding and d) Exercise related goals

Goal type Description Example quotation
Aspirational The term ‘aspirational’ distinguishes between everyday pursuits and those which were considered more unusual or ‘important’ life goals. Sometimes these types of goals were considered possible. Other times this term was used to describe patient desires considered to be unrealistic or ‘non-goals’. ‘we had one man in the current group he said ‘I want to walk up [name of hill], which is one of the tall peaks. [..]  So we put him on the programme [..] and he actually managed to get up [name of hill] after.’ (Jackie, Band 7, pulmonary rehabilitation)

 ‘sometimes you think you know that it’s unrealistic [..]  it’s a non-goal, like a new pair of lungs or I never want to be breathless again’ (Hazel, Band 7, pulmonary rehabilitation and Community)

Functional Use of the term ‘function’ reflects its use in the physiotherapist interviews. Such goals had a direct and meaningful translation into the patient’s life, as opposed to those which purely related to exercise. It encompassed an array of pursuits from very mundane activities of daily living to the more unique. We had one guy who turned around and said [laughs], he said there’s a pub at the top of [name of road] but it’s a huge hill to get there [..] it was important to him because his grandchildren liked going up there and, he was feeling he wasn’t being able to be a granddad properly because he couldn’t go out with them so much and we worked really hard with him and he managed to go and do these things’ (Penny, Band 7, pulmonary rehabilitation and Community)
Condition understanding Goals to increase patients’ understanding of their own condition were widely discussed; patients were perceived to attend having received very little information about their condition and eager to know more. They [patients] don’t know why they’re breathless, their G.P or whoever’s diagnosed them, practice nurses or consultants, never really explain to them in a huge amount of detail. […] So they’re very keen to learn, they’re very keen to find out more to be able to maintain their health for as long as possible’. (Richard, Band 6, pulmonary rehabilitation)
Exercise Exercise goals were those which related to improving physical performance in a specific exercise or physical outcome such as an increase in walking distance, or lower BORG breathlessness scores. ‘I have target goals and actual goals on an exercise programme, on an exercise sheet. [rustles papers; gets sheet to show RS] So what we would do then if that person did actually achieve one and a half minutes, what he actually achieved the following week then I would give him a target of one minute 50 seconds, constantly progressing, yeah? So then you are moving on, the goals are continually changing.’ (Georgina, Band 6, pulmonary rehabilitation)

Purposes of goal-setting  There was a distinction made between patient-oriented goals (having direct relevance to patients’ concerns) and professional or service-oriented goals:

‘you do have your generalised goals of you know broad things like improving anticipatory care erm but I don’t think ….that’s something you want all COPD patients […] When I think of patient specific goals I think of what does this patient want to be able to do, go to the hairdresser, the pub, get to the bathroom you know, be able to have a shower, you know things like that. I think that’s different, it’s very individualised thing it’s very different for every patient’ (Emma, Band 7, Community)

Patient-oriented purposes included seeing goal-setting as:

  • a means of giving patients hope: for example, hope that despite their difficulties with physical activity there was reason to continue‘It’s not pleasant to start exercising, for these patients, it’s not pleasant for anyone who’s unfit to get fit again, it’s even, you know, it, it’s much, much worse for them so they need to have that little bit of light at the end of the tunnel, something that they’re aiming for.’ (Hazel, Band 7, pulmonary rehabilitation and Community)
  • a vehicle for enabling patients to return to valued activities and pursuits and so enhancing their quality of life
  • a tool to enable clinicians to individualise rehabilitation ‘we’ll ask the patients “what are your main problems?” “what do you want us to do?” so we get an idea of what the patients actually, what the patient goals are and then tailor our treatment around what they actually want’ (Jackie, Band 7, pulmonary rehabilitation)
  • a means of demonstrating progress to patients. The physios associated ‘functional’, ‘aspirational’ and ‘condition understanding’ goals strongly with patient-oriented purposes.

Profession or service-oriented purposes included

  • To adhere to professional and service expectations. Goals are required within hospital documentation and by the Chartered Society of Physiotherapy (CSP), and goal-setting was emphasised during undergraduate training. But there was some uncertainty as to its usefulness

‘I guess it’s just that the CSP tell us that we’ve got to do this, that and the other and set patient-directed goals, […] And we haven’t really analysed whether it’s that important or not and it is difficult because we’re told to do this with everyone but we’ve not really looked at everyone to see if it’s important, with everyone’. (Oliver, Band 6, pulmonary rehabilitation)

  • To demonstrate service effectiveness to commissioners, to secure continued investment in services. Goals linked to exercise were often associated with this purpose.

‘Most people make a significant improvement in sort of exercise tolerance and general well-being through the programme.  They’re sort of the goals we sort of look towards from a service point of view, functional ones are there more as an incentive.’ (Richard, Band 6, pulmonary rehabilitation)

One physio explicitly described ‘patient goals’ agreed during a goal-setting conversation as “incentives” to facilitate achievement of other goals that were aligned to demonstrating service effectiveness.  Some even questioned whether goal-setting was anything more than a “tick-box exercise” and felt there was a lack of evidence to support the usefulness of goal-setting.

‘You know I think some health care professionals think they’re a lot better than they are ‘coz they can tick a whole lot of boxes because they can achieve goals with patients. But you turn around and ask that patient what do they actually think of that healthcare professional, and they probably tell you a completely different story’ (Danielle, Band 7, Community)

 

Theme 2 – Working with goals

Only two physios reported not setting any goals with patients.

Setting goals  The process of goal-setting was often depicted as being a “negotiation”. But this idea of a negotiation was at odds with the realities of goal-setting as described by the physios. They said that while some patients arrived knowing what they wanted to achieve, this was not the norm, with most patients struggling to identify goals. Many physios described the process of collaboration within goal identification to be challenging, and this created tension between a desire for meaningful goal identification and the time available.

‘In our own practice we still believe that setting goals by yourself is not something you can just […]..they can’t do it for the first time, they don’t even know what pulmonary rehab is, they don’t know what they gonna achieve’.  (Clint, Band 7, pulmonary rehabilitation)

‘You know time constraints and assessments as well, you just really want to get this goal and they’re going “oh I don’t know really’ (Tammy, Band 6, pulmonary rehabilitation)

Goal specificity In those cases when patients did have goals, a lack of specificity was a frequent issue. Patients were said to have general, non-specific ideas relating to broad improvements, rather than precise SMART-amenable goals.

‘I think it has to be a specific thing, I think that’s one of our big problems when they’re trying to set goals is making them specific or specific enough to be able to measure whether someone’s done it.’ (Penny, Band 7, pulmonary rehabilitation and Community)

Another issue was the setting of ‘unrealistic’ goals. Some physios felt these could potentially demotivate patients and give them a negative experience of respiratory rehabilitation.

‘You know you’ve got to be realistic as well because […] if people don’t achieve stuff then they will actually become more disillusioned.  You want to give them wins, so they feel like, you know, they’ve actually done something good’ (Georgina, Band 6, pulmonary rehabilitation)

But other physios disagreed:

‘I don’t necessarily think it has to be realistic either […] I think sometimes you need to fail your goal to set realistic goals so I don’t think that, I think it’s wrong to give people false hope but I think if they have set an unrealistic target in their head unless they fail to achieve it then they’re not going to readjust, they’re not going to reset their goal because they’ve got something higher’ (Abbey, Band 7, Acute and pulmonary rehabilitation)

Reviewing goals There was no consensus on reviewing goals. Some physios reported reviewing goals throughout the rehabilitation programme, but some did it only at the end, some not at all, and some only reviewed specific types of goals.

‘once we’ve managed to get something down on paper, keeping them motivated to actually see through that goal, […] we used to kind of review it half way and review it at the end and now we kind of probably every week we do a little five minutes at the end of, how we going with our goals, we give them sheets to take home so it’s pinned up, we have a copy, they have a copy’  (Penny, Band 7, pulmonary rehabilitation and Community)

‘I must admit it’s not very formal our goal-setting and in the past certainly with [service name] it’s always been sort of at the back of their minds rather than the forefront.  Unfortunately, although we do identify [goals] there and then they’re generally not addressed throughout the programme. […]  I mean we do keep score sheets, its more objective […]  So obviously we’ve got good objective outcomes each time they come which we’re constantly reviewing.  But in terms of the more practical, functional goals they come up with themselves it’s not very well documented.’ (Richard, Band 6, pulmonary rehabilitation)

There was recognition that the patients’ and physios’ needs regarding goal setting reviews often differed.

‘Everything we do has to have a measurable difference, […] and I agree with that because I think that that’s absolutely important I  just don’t necessarily think that all the objective outcome measures that we use actually capture what we need to capture’ (Bernice, Band 8, Acute and pulmonary rehabilitation)

‘I find it really difficult to make goals SMART […] like getting them to even measure how far they can walk now versus what they’d like to be able to do because it’s like so abstract, isn’t it? […] (Nat, Band 7, pulmonary rehabilitation and Community)

 

Theme 3 – Influences on collaborative goal-setting

Individual Influences  

Patient: general health, comorbidities, awareness of COPD, understanding of pulmonary rehabilitation, desire for change.

Physio: attitudes to goal-setting; prior experience of goal-setting; training (undergraduate/ postgraduate).

‘Goal-setting is a nightmare. [laughs] That’s how I would describe it! With some people, not with all. I think if you goal-set with someone like me, it’s really easy because I’m goal-orientated […] and I set goals with people both in pulmonary rehab and like things like my staff and oh my God, for some people […] it’s like getting blood out of a stone’. (Nat, Band 7, pulmonary rehabilitation and Community)

 ‘I don’t do goals per se. I suppose I carry goals round in my head, but they’re probably more my goals for the patients rather than the patient orientated goals. Whereas I say, more junior staff tend then to write a problem list and a goal plan I would probably qualify that by saying maybe it’s just the difference in [..] university courses. You know, when I qualified 12 years ago, was that a priority? Whereas what’s being taught now, is more the goal perspective and the patient, you know, sort of collaborative working?’ (Kay, Band 8, Acute and pulmonary rehabilitation)

Those who remembered undergraduate training featuring goal-setting, recalled being introduced to SMART principles, the use of short and long term goals, and thinking about problem lists and goals. However, even those who did receive training at university, were uncertain how goal-setting should be implemented.

‘well we’ve talked quite a lot about this [goal-setting] over the last few months, within our team. Basically it’s difficult at the moment because I think all of us do things differently and I don’t know whether… no one really knows really whether they’re doing it right or wrong, or what’. (Oliver, Band 6, pulmonary rehabilitation)

Organisational Influences

Time pressure: Giving time to patients in consultations was considered a desirable and important thing. Time was needed for patients to consider and understand their condition, to think about their condition-related questions, and to explore how rehabilitation could influence their lives. But available time for new patient assessments varied across pulmonary rehabilitation programmes, from about 30 minutes to 1 hour.

‘I think goal setting is quite a time consuming, energy draining kind of task and I think that if no one else in the team can kind of do it, very well, or avoids it shall we say, then it’s quite a draining thing for you to have to do.’ (Nat, Band 7, pulmonary rehabilitation and Community)

‘I think it’s just the time thing again you’ve got to fit in the all your assessment, you’ve done the objective things, you spoke to them a lot during the subjective and then you start asking them about goals […] it opens up the floodgates sometimes doesn’t it?’ (Abbey, Band 7, Acute and pulmonary rehabilitation)

The physios working in the community felt less time limited than those working in pulmonary rehabilitation. However, in the community, caseload challenges were more influential; acutely unwell patients would take priority over more stable patients who were consequently left to pursue their goals alone.  The need to prioritise patients according to severity was perceived as more pronounced in the acute medical setting; with a heavy caseload of sick people to manage, time spent with any one individual patient was noted as brief.  In these areas, goal-setting was seen as less collaborative and more based around acute needs and discharge.

‘I mean I don’t know that many people still do goals on, on the wards. I think mainly on the wards it’s more this is acute admission we’ve got to get you better and well enough to go home and goals aren’t necessarily thought about’ (Penny, Band 7, pulmonary rehabilitation and Community)

Financial cuts had left multidisciplinary PR programmes marginalised by the loss of professional input. So some physios described having little access to, or input from, other disciplines and felt this affected the time available for goal-setting. Physios felt unable to include every recommended component, or to do everything that might be considered ‘ideal’; collaborative goal-setting was one such component.

‘So, things are getting done at probably 60%, coz there’s only me, rather than a team of four of us you know, everybody getting 100% of their job […] There’s only so much one person can do really.’ (Kay, Band 8, Acute and pulmonary rehabilitation)

‘I don’t have the luxury of time necessarily, so I’ll probably hone in on what I perceive as the important elements, so I don’t know whether I’m doing a, a, a token gesture at goal-setting to some extent. If, if it’s not simple to do, have I got the time to go back and revisit it on an individual basis with patients? Probably not’.  (Kay, Band 8, Acute and pulmonary rehabilitation)

Service needs  Rehabilitation services were seen as needing to justify their existence by providing evidence of short and long term improvements, not only to gain additional funding but just to maintain existing funding. Clinical outcomes demonstrating patient benefit were required by commissioners, and in this respect exercise goals could be seen as contributory. Service-oriented goals were often prioritised over more patient-oriented goals, which was challenging to the practice of collaborative goal-setting.

‘we use lots of outcomes, just as a service we’re always trying to prove that we’re worthwhile. That we’re worth spending all that money on, so we use lots of outcomes, and then a lot of the goals are built around those outcomes themselves’. (Richard, Band 6, pulmonary rehabilitation)

‘how much does pulmonary rehab cost? Well not a lot so the investment is probably worthwhile and if you can demonstrate that to the commissioners surely that’s of benefit.  So there are other benefits of looking at how you set your goals in a wider setting.’ (Steve, Band 8, Acute)

Approaches used by physios to assist with goal-setting

  • Listening to the patient, to learn how their lives were affected by their condition and really mattered to them.

‘I think the process of getting in there, again, for me is to do with […] finding out what it is what  makes  that  patient  tick  so  what  it  is  that  is  high  on  their,   functionally  really  what  it  is  what  they  would  like  to  achieve’  (Danielle, Band 7, Community)

  • Prompting patients to think about what they wanted to achieve initially, before following this up in the second or third week of rehabilitation to agree any goals.

‘So we kind of tell them to be thinking about goals on the first day as well, on the assessment day […] goal setting used to be the 3rd week, but now we’ve moved it to the 2nd week’ (Clint, Band 7, Pulmonary Rehabilitation)

  • Using responses from a disease specific questionnaire, such as the Chronic Respiratory Questionnaire (CRQ) to help patients identify any things they could not do, but would like to.

‘If they can’t think of a goal, I then go on to say “well what are you having problems with?” if they can’t tell me then we get the CRQ out and say “well you’ve ticked that you can’t bend down and you’re struggling to get dressed, is that something you want to improve on?’ (Jackie, Band 7, Pulmonary Rehabilitation)

  • Dealing with unrealistic goals. Unless the goal was something completely unobtainable (like wanting a new pair of lungs), most physios used the strategy of breaking large, potentially unrealistic, goals down into smaller ones, rather than not working towards their patients’ goals at all, in an effort to keep their patients’ experiences of respiratory rehabilitation positive.

Some physios had issues with using a problem-focused approach to collaborative goal-setting because a) a patient’s reported problems did not always equate to a desirable goal from the patient’s perspective, or b) patients might not perceive themselves to have any particular difficulty.  The latter may have been because any relinquished or reduced activities had been given up gradually (due to the gradual onset of their COPD), or because they did not perceive COPD to have significantly affected their lifestyle.

‘Sometimes it is really hard to find a goal for people.  I’ve had quite a few patients who I actually haven’t been able to set and usually no matter how, which way you ask them you know to get a goal they just can’t come up with anything  and then you feel like you’re telling them goals to achieve, because then you say “well, what about if you can walk to the shops without stopping?” and they’re like “ok” but it might not be important to them they might not care that they have to stop 5 times, they might be so used to doing that be now that it doesn’t make a difference?’ (Tammy, Band 6, pulmonary rehabilitation)

Conclusion

Goal-setting in relation to COPD has been found to be challenging for respiratory physiotherapists, with emphasis on the difficulty surrounding goal identification, and clinical practices vary. There is considerable uncertainty as to how goal-setting should be approached and there are times when goal-setting is driven by service need, rather than patient values. This creates tension for clinicians who have to fulfil both patient needs and service needs. In addition to being given the time and resources necessary to undertake goal-setting, clinicians may also need additional training to help them resolve some of these issues. This work highlights a need for wider discussion to clarify the purpose and implementation of goal-setting in respiratory rehabilitation.

“Giving hope, ticking boxes or securing services? A qualitative study of respiratory physiotherapists’ views on goal-setting with people with chronic obstructive pulmonary disease” Clinical Rehabilitation. 2016. Epub ahead of print

Authors: Summers RH, Ballinger C, Nikoletou D, Garrod R, Bruton A, Leontowitsch M.

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New PhD studentship opportunity for 2017

phdCome and work with me! A new full-time PhD studentship will be open for applications next year (2017).  I will let you know when the advertisement is prepared and released, so this blogpost is just a heads up.  The studentship will only be open to UK/EU students, because the funding available is insufficient to cover international fees. Applicants will need a 2:1 degree or higher, and to have skills in a numerate discipline like engineering, ideally with signal processing skills and experience in use of Matlab.

The working title is Automated Analysis of Lung Sounds as a Predictor of Ventilator Associated Pneumonia.  This work is being funded jointly by the NIHR Southampton Respiratory Biomedical Research Unit and an asthma charity called AAIRYou will be supervised by Prof Anna Barney (Faculty of Engineering and the Environment (FEE)), Prof Mike Grocott (Faculty of Medicine), and me – Prof Anne Bruton (Faculty of Health Sciences). We are all three based at the University of Southampton and you will be registered with FEE for the duration of your PhD.

Some background for this PhD

I have blogged about lung sounds before. See here,  here and here.  Standard lung auscultation provides an assessment of airway patency and geometry, and parenchymal normality, but the information it gives is subjective and qualitative. Computer aided lung sound analysis (CALSA) removes the subjectivity and allows quantification of sounds and their characteristics (intensity, frequency) (Earis & Cheetham 2000). We hypothesise that information derived from CALSA will aid the early detection, diagnosis and monitoring of acquired pulmonary complications. Most research in this field has been conducted in controlled, laboratory environments using multiple sensors, but we have established that reliable lung sound data can be recorded with a single sensor in an outpatient clinical environment (Marques et al. 2009), and we have current PhD students who have successfully collected lung sound data from inpatient ward environments.

Acquired pulmonary complications (atelectasis, infection, pneumonia) are common in several patient groups, particularly in post-operative and intensive care populations. Mechanically ventilated patients are at high risk for developing nosocomial pneumonia or tracheobronchitis. In general, the frequency of infection increases with the duration of mechanical ventilation, but the risk appears to be greatest in the first week of intubation (Ahmed 2001). Ventilator acquired tracheobronchitis (VAT) represents an intermediate process between lower respiratory tract colonisation and ventilator-associated pneumonia (VAP), which is an important cause of morbidity and mortality with a significant economic impact on health care resources, despite advances in antimicrobial therapy and better supportive care (Rotstein et al. 2008). The incidence of VAP has been reported to range from 10% to 20% of intensive care unit patients (Rewa 2011). It is suggested that there is a short therapeutic window between the development of VAT and the progression to VAP, but one of the challenges to optimal management is having an early and accurate diagnosis, as delays in therapy are associated with increased mortality. Formal diagnosis of VAP usually comprises clinical signs and symptoms, microbiological data, and radiographic findings; but there is currently no consensus on diagnostic criteria for VAT (Craven et al. 2009).

Lung sound data are simple to collect (noninvasively at the bedside), using a digital stethoscope, and can provide data for quantitative and objective tracking of changes in respiratory health status. In this PhD, data from a cohort of ventilated patients in an intensive care setting would be collected. Data would be acquired at multiple time-points, from admission to discharge (or death) together with a clinical and pathological characterisation of the progression of any acquired pulmonary complications. Chest x-rays are routinely, and frequently, taken in the ICU environment for clinical need (e.g. checking placement of endo-tracheal and naso-gastric tubes, checking central line placement, monitoring clinical changes), so there will be opportunities to compare acoustic with radiological findings.

We plan to start initial clinical data collection in advance of the enrolment of the PhD student. The PhD student would be based in the Faculty of Engineering and the Environment and focus on acoustic analysis of lung sound recordings to establish and evaluate the usefulness of extracted acoustics features (energy, energy by frequency band, spectral tilt, temporal and spectral features of adventitious sounds such as wheezes and crackles, statistical features, cepstral analysis, MFCC and PLP-CC etc). These are all analysis methods that have been used effectively to characterise other kinds of audio, in particular speech recordings. Their use in pulmonary analysis is at an early stage due to slow embedding of the use of digital stethoscopes in clinical practice and the difficulty of establishing ground truth data for in vivo recordings. They have, however, shown promise as methods for analysing recordings from patients with cystic fibrosis (Marques et al 2012), bronchiectasis (Marques et al, 2009), COPD (Bennett et al, 2014), asthma and several other lung pathologies. Feature selection techniques will be used to identify the subset of acoustic features most sensitively predictive of VAP onset and progression for use in patient monitoring. These will then be incorporated into an automated system for identifying patients at risk of developing VAP in order to provide diagnostic support for clinical staff.

The PhD student will spend the first 9 months familiarising him/herself with the literature on lung sounds and their analysis, and establishing a set of acoustic features that can be extracted from the data sample and which have the potential to change with disease onset and progression. The next phase of the work from 9 to 18 months will be testing the statistical sensitivity of the features to known changes in patient respiratory health status to establish which should be selected as part of a predictive system. The final phase of the work will be a prospective study to test whether onset of VAP can be reliably predicted by the selected features, which will occur in parallel with thesis preparation.

Close-up of stethoscope on laptop keyboard

References

Ahmed QA, Niederman MS (2001) Respiratory infection in the chronically critically ill patient: ventilator-associated pneumonia and tracheobronchitis. 22(1) 72-85

Beck R et al. (2007) Computerized acoustic assessment of treatment efficacy of nebulized epinephrine and albuterol in RSV bronchiolitis. BMC Pediatr. 7:22

Bennett et al. (2015) The relationship between crackle characteristics and airway morphology in COPD. Respiratory Care. 60 (3): 412-421.

Craven DE et al. (2009) Ventilator-associated tracheobronchitis: the impact of targeted antibiotic therapy on patient outcomes.Chest135:521-8

Earis JE, Cheetham BMG (2000) Current methods used for computerized respiratory sound analysis. Eur Respir Rev 10:586-590.

Marques A et al. (2009) The reliability of lung crackle characteristics in cystic fibrosis and bronchiectasis patients in a clinical setting. Physiological Measurement. 30:903-912

Marques et al. (2012) Are crackles and appropriate outcome measure for airway clearance therapy? Respiratory Care. 57(9), 1468-1475.

Murphy R.L. (2008) In defence of the stethoscope. Respir Care. 53(3):355-69

Rewa O, Muscedere J. (2011) Ventilator-associated pneumonia: update on etiology, prevention, and management. Curr Infect Dis Rep. 13(3):287-95

Rotstein C et al. (2008) Clinical practice guidelines for hospital-acquired pneumonia and ventilator-associated pneumonia in adults. Can J Infect Dis Med Microbiol. 19:19-53.

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Breathing exercises for adults with asthma

This is an early version of an invited paper I produced for Drug and Therapeutics Bulletin (2015 53:126-9 doi:10.1136/dtb.2015.11.0361). The published version is very different!

Introduction Asthma is still amongst the commonest long-term conditions, it is incurable, and outcomes have stopped improving, despite clinicians’ best efforts using pharmacological approaches (Martinez & Vercelli, 2013). There is considerable public interest in the use of non-pharmacological approaches in the treatment of asthma, and particularly in the use of breathing exercises (Bruton & Thomas 2100). Surveys suggest many people with asthma use them, often without the knowledge of their clinical team. However, the phrase ‘breathing exercises’ is vague and encompasses many different techniques, only some of which have a convincing evidence base. The techniques with the strongest evidence base are those that aim to ‘retrain’ breathing pattern to encourage patients to breathe through the nose, to breathe more slowly and regularly, and to reduce upper thoracic movement. The role of breathing exercises within the management of asthma has been controversial, partly because early proponents made exaggerated, implausible claims of effectiveness. Recent evidence suggests that breathing retraining programmes are effective in improving patient-reported outcomes such as symptoms, quality of life and psychological impact; and may reduce the use of rescue bronchodilator medication. This has resulted in endorsement of breathing retraining as an add-on treatment in asthma in systematic reviews and guidelines. The guidance is only applicable to adults with asthma, as there is little paediatric evidence beyond anecdote. Despite the observed clinical benefits in adults with asthma, there is currently no convincing evidence that airways physiology, hyper-responsiveness or inflammation is affected by breathing exercises. The mechanism behind breathing retraining therefore remains uncertain, with both psychological and physiological theories proposed.

Background Breathing exercises for asthma can be broadly divided into four groups: exercises aimed at manipulating the pattern of breathing (breathing retraining), exercises aimed at increasing the strength and/or endurance of the respiratory muscles (inspiratory muscle training); exercises aimed at whole body conditioning (aerobic training); and exercises aimed at increasing the flexibility of the thoracic cage and improving posture (musculoskeletal training). Some individual techniques may address more than one of these group aims. Each group of exercises contains a range of approaches and rationales. In addition there are specific technologies/ equipment that can be used to provide biofeedback during exercises. The main focus in this article will be on techniques with the most convincing evidence base, which are the ones used in breathing retraining.

Breathing retraining exercises aimed at manipulating the pattern of breathing include: physiotherapy techniques (such as Papworth), yoga breathing techniques, Buteyko breathing techniques, and improving breath control through singing or musical instruments. Some of the issues with all breathing retraining trials are the lack of detail in the description of the techniques used, and the lack of uniformity in use of language (Bruton et al, 2011). In RCTs reported by Thomas et al (2003, 2009), and Holloway & West (2007) the phrase ‘diaphragmatic breathing’ is used.  In reality, in the absence of phrenic nerve malfunction, all breathing patterns involve diaphragmatic activity, so this phrase is not an accurate description, but has become synonymous with breathing with more movement from the abdomen than upper chest. One problem with the term diaphragmatic breathing is that it can be interpreted to mean ‘slow and deep’ or ‘normal rate and tidal volume’ breathing, depending on when and where you were trained (Bruton et al, 2011). Nevertheless, most breathing retraining packages include greater emphasis on abdominal and lower thoracic excursion during inspiration, with reduced emphasis on upper thoracic excursion. But this is only one element of the package. Breathing retraining is a complex intervention frequently comprising multiple components (both respiratory and non-respiratory). Respiratory components involve some form of breathing pattern manipulation, while non-respiratory components may include, for example, varying amounts of nutritional advice, medication usage advice, and psychological support to address the associated anxiety which can accompany asthma (Thomas et al, 2011).

Main body The evidence for breathing exercises other than breathing retraining is either weak or non-existent. Although musculoskeletal training to increase flexibility and improve posture in asthma has some strong clinical proponents, there is insufficient trial evidence to support their use. Specific named techniques such as the Alexander Technique (which is a form of therapy involving postural realignment and relaxation) have no trial evidence in asthma found to be suitable for inclusion in a recent Cochrane review(Dennis & Cates, 2012). Manual therapy techniques aimed at increasing the movement of the ribcage and spine to improve lung function also have insufficient evidence to support or refute their use for patients with asthma (Hondras et al, 2005). There has been recent interest in music therapy for asthma (both listening and playing), and there is some logic to the use of breath control techniques associated with singing, or playing a wind instrument, but there is again insufficient evidence to support its use (Sliwka et al, 2014). None of these breathing exercises/ techniques is recommended within current guidelines for asthma. There is, however, some evidence that inspiratory muscle training may have an effect. A recent Cochrane review included five studies involving a total of 113 adults (Silva et al 2013), although three of these were from a single research group. Inspiratory muscle strength generally increased significantly (as you would expect after resistance training for any skeletal muscle), but no clinical benefit (such as change in quality of life or breathlessness) was observed. The review concluded that there was currently no evidence to support or refute the use of inspiratory muscle training in asthma.

Physical training also has some positive evidence. One Cochrane review of physical training for asthma (Ram et al, 2005 ), based primarily on paediatric studies, concluded that while physical training improves cardiopulmonary fitness, it has no effect on resting lung function or number of days with wheeze. A systematic review (Pakhale et al, 2013) included 23 studies (total number of participants not documented). Although the authors stated that physical training might reduce airway inflammation in asthma, the review was essentially inconclusive. A more recent Cochrane review in 2013 concluded physical training showed significant improvement in maximum oxygen uptake, but no effects were observed in other measures of pulmonary function (Carson et al, 2013). However, the training was well tolerated and although physical training may have no specific asthma-related effects, the general benefits of physical training mean that some authors  recommend its use in asthma (Bott et al, 2009), even though they are not specific about dose/ duration/type of training to be used. The Cochrane review concluded: “People with stable asthma should be encouraged to participate in regular exercise training, without fear of symptom exacerbation” (Carson et al, 2013).

Breathing retraining The breathing retraining techniques most frequently investigated in research trials have been physiotherapist administered breathing exercises (Papworth and similar) (Holloway & West 2007; Laurino et al, 2012; Thomas et al, 2003, 2009) the Butekyo breathing method (Cooper et al, 2003; Cowie et al, 2008; Opat et al, 2000) and yogic breathing (Manocha et al, 2002; Singh et al, 2012; Singh et al, 1990). Although each has a different philosophical standpoint and rationale, there are considerable overlaps within their delivery methods. Of the three approaches, physiotherapy and Buteyko have the higher level of evidence and are now mentioned in BTS/SIGN guidelines for asthma management (British guideline on the management of asthma, 2014). Although some practitioners are applying these techniques clinically to children and teenagers, the only robust current research trial evidence applies to adults, with a recent Cochrane search for evidence in other age groups finding zero papers for inclusion in their review (Barker et al, 2013).

The general aims of breathing retraining are to ‘normalise’ breathing pattern, usually by adopting a slower respiratory rate with longer expiration and reduction in overall ventilation. Use of abdominal rather than the upper-chest and accessory muscles of ventilation in resting breathing, and nasal rather than mouth breathing, are also frequently stressed. The rationale for this retraining is based on the assumption that some people with asthma have abnormal or dysfunctional breathing patterns, either continuously or intermittently in association with bronchospasm. The evidence for this assumption is fairly weak, as few reliable studies have compared breathing patterns in people with asthma to healthy subjects, particularly at times of bronchoconstriction. People with asthma (even mild well controlled asthma) have been found on average to have a lower arterial and end-tidal carbon dioxide tension than matched non-asthmatic subjects, indicating a tendency to over-breathe (Osborne et al, 2000). There is also indirect evidence of dysfunctional breathing from UK surveys reporting 1/3 of women and 1/5 of men treated for asthma in general practice to have symptoms suggestive of hyperventilation (Thomas et al, 2001) and from Spain (Martinez-Moragon et al, 2005)reporting that 1/3 of asthma patients in a Spanish pulmonology clinic had such symptoms. Approximately 1/5 of patients attending UK difficult asthma clinics were found after detailed assessment to have functional breathing disorders (including dysfunctional breathing and vocal cord dysfunction) as a major factor in their illness (Heaney & Robinson, 2005).

Breathing retraining for asthma should be considered as a complex multicomponent behavioural change intervention involving both instructional and practice phases. In clinical practice, the instruction phase of the intervention is conventionally delivered individually via face-to-face methods between a patient and a therapist. Although some studies have used small group delivery, no direct comparisons have yet been trialled for group versus one-to-one delivery. Some trials have used alternative ‘distance’ delivery methods such as in an Australian study investigating the effects of two breathing training programmes delivered as a videotaped instruction programme (Slader et al, 2006). Both programmes were associated with improved health status and major reductions in bronchodilator use from baseline values. They have subsequently been made available as Internet downloads and used in Australia to improve asthma control in routine practice. The minimum length and number of instruction sessions required to achieve improvement is not known, and in clinical practice tends to be individualised according to the needs / learning speed of the patient. In our experience with physiotherapy breathing retraining, 3-4 instruction sessions spread over a period of about 6 weeks are effective. Patients are encouraged to put the various techniques into practice on a daily basis and to try to incorporate them into daily routines until they become ‘second nature’ and embedded into daily life. The ideal number and duration of practice sessions is also unknown, and as with the instruction sessions, is likely to vary between individuals.

Breathing retraining generally involves a ‘package’ of components. The Papworth (physiotherapy), Yoga, and Buteyko packages all have some core similarities, with breathing pattern modification being the primary component. Other common elements are advice on route of breathing, use of breath holding, relaxation and home exercises. The more variable elements across the packages are nutritional advice, medication usage advice, asthma education, aerobic exercise prescription, and use of biofeedback devices (such as use of capnometry, breathing rate, heart rate variability).

Evidence for breathing retraining in asthma One systematic review of breathing exercises in the treatment of asthma performed for the US Agency for Healthcare Research and Quality found 22 studies (O’Connor et al, 2012). Although these were heterogeneous in terms of methodology, intervention and quality, the review found that hyperventilation reduction techniques achieved a medium to large reduction in symptoms and reduction in medication use (1.5-2.5 puffs of Beta2 agonist per day), although with no improvement in pulmonary function. Generally, improvements were seen in patient reported outcome measures, particularly quality of life, rescue medication requirement and symptoms, with lesser or absent improvements in physiological disease parameters. The review concluded that ‘Behavioral approaches that include hyperventilation reduction techniques can improve asthma symptoms or reduce reliever medication use over 6 to 12 months in adults with poorly controlled asthma, and have no known harmful effects.’  An updated Cochrane review in 2013 of ‘Breathing exercises for adults with asthma’ (Freitas et al, 2013) with more restrictive criteria considered 13 studies involving 906 participants. Again, considerable heterogeneity was found, but six of seven studies reporting symptom control showed significant improvements with breathing exercises. All eight studies that assessed quality of life reported an improvement in this outcome. Effects on lung function were more variable, with no difference reported in five of the eleven studies, while the other six showed a significant difference favouring breathing exercises. Meta-analysis was possible only for symptoms and quality of life, and showed a significant difference favouring breathing exercises for both parameters. Recent guidelines now incorporate recommendations that breathing retraining exercises should be considered in adult asthma, with the 2015 GINA iteration stating that ‘Breathing exercises may be a useful supplement to asthma pharmacotherapy’ (Grade B). The non-pharmacological management section of the BTS-SIGN UK Asthma Guideline (2014) gives grade A recommendation to the statement ‘Breathing exercise programmes (including physiotherapist-taught methods) can be offered to people with asthma as an adjuvant to pharmacological treatment to improve quality of life and to reduce symptoms’.

 Targeting – who benefits from breathing retraining? Asthma encompasses a variety of phenotypes, and different therapeutic approaches are effective in different patients (Anderson, 2008). At present, data from published trials suggest that those who would benefit most from breathing retraining are those with impaired quality of life (when assessed with a validated questionnaire such as the AQLQ) despite standard medication. Although intuitively one might think those with symptoms of hyperventilation would be more likely to benefit, in the largest trial to date no significant difference in response to training from those with higher hyperventilation symptom scores (evaluated using the Nijmegen questionnaire) or lower baseline carbon dioxide tension; similarly, anxiety and depression did not predict the response to treatment (Thomas et al, 2009).

Breathing retraining requires considerable commitment from the individual patient in terms of time and effort. It suits those who are happy to be involved with self-management but is unlikely to be effective in patients who prefer a ‘quick fix’, or who lack sufficient motivation to practice the techniques regularly. A problem for many clinicians and patients is accessing therapists who can provide this training, which can be problematic for many respiratory specialists, and even more so for community-based generalists. The cost-effectiveness of increasing access to respiratory physiotherapists or other suitable professionals has not been assessed. Currently many patients who are interested in this type of treatment can only access it by paying unregulated therapists or by self-help books, internet pages or You Tube films of unknown efficacy. We are currently investigating the clinical and cost-effectiveness of an interactive ‘digital’ audio-visual breathing training programme (which can be delivered by internet or DVD) compared to face-to-face programmes and usual care, in the BREATHE study (Bruton et al, 2013). Potentially, this could allow a method of allowing large numbers of people to access the treatment in a convenient and inexpensive way.

Conclusion Asthma is a complex, multi-faceted condition, and control is sub-optimal for most patients. There is now sufficient evidence to recommend breathing retraining as an adjunctive therapy for the management of asthma, provided it is delivered responsibly within the context of optimal medical care. It is unlikely that breathing retraining will affect the pathophysiology of asthma, although may improve symptoms, increase quality of life, and may reduce rescue bronchodilator use. For patients who are not achieving adequate control despite apparently adequate pharmacological treatment, informing them of the possibility of breathing retraining and referring them to an appropriate source of instruction would be in agreement with current evidence and guidelines. Access to trained therapists is an on-going issue, but future research may allow greater access to effective programmes delivered in other ways.

References

Anderson, G. P. (2008). Endotyping asthma: new insights into key pathogenic mechanisms in a complex, heterogeneous disease. Lancet, 372(9643), 1107-1119. doi: 10.1016/s0140-6736(08)61452-x

Barker, N. J., Jones, M., O’Connell, N. E., & Everard, M. L. (2013). Breathing exercises for dysfunctional breathing/hyperventilation syndrome in children. Cochrane Database Syst Rev, 12, CD010376. doi: 10.1002/14651858.CD010376.pub2

Bott, J., Blumenthal, S., Buxton, M., Ellum, S., Falconer, C., Garrod, R., . . . White, J. (2009). Guidelines for the physiotherapy management of the adult, medical, spontaneously breathing patient. Thorax, 64 Suppl 1, i1-51. doi: 10.1136/thx.2008.110726

British guideline on the management of asthma. (2014). Thorax, 69 Suppl 1, 1-192.

Bruton, A., Garrod, R., & Thomas, M. (2011). Respiratory physiotherapy: towards a clearer definition of terminology. Physiotherapy, 97(4), 345-349. doi: 10.1016/j.physio.2010.12.005

Bruton, A., Kirby, S., Arden-Close, E., Taylor, L., Webley, F., George, S., . . . Thomas, M. (2013). The BREATHE study: Breathing REtraining for Asthma–Trial of Home Exercises. a protocol summary of a randomised controlled trial. Prim Care Respir J, 22(2), PS1-7. doi: 10.4104/pcrj.2013.00047

Bruton, A., & Thomas, M. (2011). The role of breathing training in asthma management. Curr Opin Allergy Clin Immunol, 11(1), 53-57. doi: 10.1097/ACI.0b013e3283423085

Carson, K. V., Chandratilleke, M. G., Picot, J., Brinn, M. P., Esterman, A. J., & Smith, B. J. (2013). Physical training for asthma. Cochrane Database Syst Rev, 9, CD001116. doi: 10.1002/14651858.CD001116.pub4

Cooper, S., Oborne, J., Newton, S., Harrison, V., Thompson Coon, J., Lewis, S., & Tattersfield, A. (2003). Effect of two breathing exercises (Buteyko and pranayama) in asthma: a randomised controlled trial. Thorax, 58(8), 674-679.

Cowie, R. L., Conley, D. P., Underwood, M. F., & Reader, P. G. (2008). A randomised controlled trial of the Buteyko technique as an adjunct to conventional management of asthma. Respir Med, 102(5), 726-732. doi: 10.1016/j.rmed.2007.12.012

Dennis, J. A., & Cates, C. J. (2012). Alexander technique for chronic asthma. Cochrane Database Syst Rev, 9, CD000995. doi: 10.1002/14651858.CD000995.pub2

Freitas, D. A., Holloway, E. A., Bruno, S. S., Chaves, G. S., Fregonezi, G. A., & Mendonca, K. P. (2013). Breathing exercises for adults with asthma. Cochrane Database Syst Rev, 10, CD001277. doi: 10.1002/14651858.CD001277.pub3

Global Strategy for Asthma Management and Prevention, Global Initiative for Asthma (GINA). April 2015). from http://www.ginasthma.org/

Heaney, L. G., & Robinson, D. S. (2005). Severe asthma treatment: need for characterising patients. Lancet, 365(9463), 974-976. doi: 10.1016/s0140-6736(05)71087-4

Holloway, E. A., & West, R. J. (2007). Integrated breathing and relaxation training (the Papworth method) for adults with asthma in primary care: a randomised controlled trial. Thorax, 62(12), 1039-1042. doi: 10.1136/thx.2006.076430

Hondras, M. A., Linde, K., & Jones, A. P. (2005). Manual therapy for asthma. Cochrane Database Syst Rev(2), CD001002. doi: 10.1002/14651858.CD001002.pub2

Laurino, R. A., Barnabe, V., Saraiva-Romanholo, B. M., Stelmach, R., Cukier, A., & Nunes Mdo, P. (2012). Respiratory rehabilitation: a physiotherapy approach to the control of asthma symptoms and anxiety. Clinics (Sao Paulo), 67(11), 1291-1297.

Manocha, R., Marks, G. B., Kenchington, P., Peters, D., & Salome, C. M. (2002). Sahaja yoga in the management of moderate to severe asthma: a randomised controlled trial. Thorax, 57(2), 110-115.

Martinez-Moragon, E., Perpina, M., Belloch, A., & de Diego, A. (2005). [Prevalence of hyperventilation syndrome in patients treated for asthma in a pulmonology clinic]. Arch Bronconeumol, 41(5), 267-271.

Martinez, F. D., & Vercelli, D. (2013). Asthma. Lancet, 382(9901), 1360-1372. doi: 10.1016/s0140-6736(13)61536-6

O’Connor, E., Patnode, C. D., Burda, B. U., Buckley, D. I., & Whitlock, E. P. (2012). Breathing Exercises and/or Retraining Techniques in the Treatment of Asthma: Comparative Effectiveness. Rockville MD.

Opat, A. J., Cohen, M. M., Bailey, M. J., & Abramson, M. J. (2000). A clinical trial of the Buteyko Breathing Technique in asthma as taught by a video. J Asthma, 37(7), 557-564.

Osborne, C. A., O’Connor, B. J., Lewis, A., Kanabar, V., & Gardner, W. N. (2000). Hyperventilation and asymptomatic chronic asthma. Thorax, 55(12), 1016-1022.

Pakhale, S., Luks, V., Burkett, A., & Turner, L. (2013). Effect of physical training on airway inflammation in bronchial asthma: a systematic review. BMC Pulm Med, 13, 38. doi: 10.1186/1471-2466-13-38

Ram, F. S., Robinson, S. M., Black, P. N., & Picot, J. (2005). Physical training for asthma. Cochrane Database Syst Rev(4), CD001116. doi: 10.1002/14651858.CD001116.pub2

Silva, I. S., Fregonezi, G. A., Dias, F. A., Ribeiro, C. T., Guerra, R. O., & Ferreira, G. M. (2013). Inspiratory muscle training for asthma. Cochrane Database Syst Rev, 9, CD003792. doi: 10.1002/14651858.CD003792.pub2

Singh, S., Soni, R., Singh, K. P., & Tandon, O. P. (2012). Effect of yoga practices on pulmonary function tests including transfer factor of lung for carbon monoxide (TLCO) in asthma patients. Indian J Physiol Pharmacol, 56(1), 63-68.

Singh, V., Wisniewski, A., Britton, J., & Tattersfield, A. (1990). Effect of yoga breathing exercises (pranayama) on airway reactivity in subjects with asthma. Lancet, 335(8702), 1381-1383.

Slader, C. A., Reddel, H. K., Spencer, L. M., Belousova, E. G., Armour, C. L., Bosnic-Anticevich, S. Z., . . . Jenkins, C. R. (2006). Double blind randomised controlled trial of two different breathing techniques in the management of asthma. Thorax, 61(8), 651-656. doi: 10.1136/thx.2005.054767

Sliwka, A., Wloch, T., Tynor, D., & Nowobilski, R. (2014). Do asthmatics benefit from music therapy? A systematic review. Complement Ther Med, 22(4), 756-766. doi: 10.1016/j.ctim.2014.07.002

Thomas, M., Bruton, A., Moffat, M., & Cleland, J. (2011). Asthma and psychological dysfunction. Prim Care Respir J, 20(3), 250-256. doi: 10.4104/pcrj.2011.00058

Thomas, M., McKinley, R. K., Freeman, E., & Foy, C. (2001). Prevalence of dysfunctional breathing in patients treated for asthma in primary care: cross sectional survey. BMJ, 322(7294), 1098-1100.

Thomas, M., McKinley, R. K., Freeman, E., Foy, C., Prodger, P., & Price, D. (2003). Breathing retraining for dysfunctional breathing in asthma: a randomised controlled trial. Thorax, 58(2), 110-115.

Thomas, M., McKinley, R. K., Mellor, S., Watkin, G., Holloway, E., Scullion, J., . . . Pavord, I. (2009). Breathing exercises for asthma: a randomised controlled trial. Thorax, 64(1), 55-61. doi: 10.1136/thx.2008.100867

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Trial recruitment blues

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Academic Adventures in Amsterdam: my respiratory research team at the ERS

Amsterdam ERSAt the end of September some of the respiratory research team from the Faculty of Health Sciences, University of Southampton attended the European Respiratory Society (ERS) Congress in Amsterdam. This is a huge conference, with over 22,000 delegates and a strong medical bias, but is an excellent forum for physiotherapists, nurses and others working in the respiratory field to disseminate their work and network with the great and the good. As an avid Tweeter I was busy during the 5-day conference and have Storyfied my conference experience here.

In this blogpost I am sharing a bit more detail about just one area of the work we presented. Two PhD students, Roxy Tehrany (now Dr Roxy – yay!) and Fatimah Al Sheikh, were presenting their research into breathing patterns. Roxy’s work was on breathing patterns created during different types of speech, while Fatimah was looking at the stability of breathing patterns within individuals over time.

This is one of Roxy’s posters comparing breathing patterns in healthy people and those with chronic respiratory disease.Roxy poster health vs disease

As physiotherapists we observe clinically that people with respiratory problems breathe ‘differently’ to healthy people, but this has rarely been quantified (partly because of the many difficulties that surround recording and analysing some elements of breathing pattern). We often note that people with respiratory problems breathe with more movement of their upper chest than healthy people – who tend to breathe more from the abdomen. Roxy’s work was using a tried and tested piece of equipment called Respiratory Inductive/ Inductance Plethysmography (RIP) to record chest wall and abdominal movements during breathing. She invited a group of 20 patients with chronic respiratory disease and a group of 20 age-matched healthy adults to have their breathing patterns recorded while breathing quietly and while speaking. She found that there were statistically significant differences in the way that the two groups breathed, but that this was not always as we had anticipated – for example the healthy group had greater movement from the chest than the respiratory disease group. This finding was consistent for both quiet breathing and during all three speaking tasks they were given (reading, conversation and counting). We have a few theories as to why we returned this result – one is that the band that goes around the chest during RIP is not able to distinguish between lower chest and upper chest movement, but conflates the two to give ‘generalised’ chest movements. Another possibility is that people with chronic respiratory disease have to work harder to breathe which may require more abdominal movement. However, this counter intuitive finding would need to be confirmed in a much larger sample before we can accept it as ‘real’.

Meanwhile, Fatimah was conducting experiments to test whether breathing patterns remained stable within individuals over time, and / or were affected by posture. She did this by inviting 46 healthy participants to attend for recording of their breathing patterns in sitting and lying (again using RIP) during four different recording sessions over a period of one week. This is the poster she presented at the ERS.

Fatimah poster ERS

Her analysis showed that both timing and regional components of breathing pattern gave ‘good’ test-retest reliability (using both relative and absolute estimates) in both positions, but that the sitting position gave the higher reliability estimates. This suggests that in healthy participants, breathing pattern is stable within individuals and that the sitting position may be preferable to the supine (lying) for taking repeated measurements over time. Stability is one of the characteristics that is desirable for any measurement to have if it is to be useful as an outcome measure. Another characteristic of a useful outcome measure is that it should be responsive to change. For example, height (in adults) is a fairly stable measurement – but unlikely to show much change in response to any intervention. If you were testing the effects of a new diet, you might use your weight to assess the outcome, but you would not use height.

Roxy wanted to do some further work to explore whether breathing patterns had any value as an outcome measure for physiotherapy interventions. Before setting up a randomised controlled trial we wanted to try and get some ‘proof of principle’ data to see if breathing patterns were responsive to change. We considered two physiotherapy related interventions that we thought might induce change in breathing pattern 1) breathing retraining and 2) pulmonary rehabilitation. We are currently conducting a small study measuring patterns before and after breathing retraining, but Roxy has now completed a small study measuring patterns before and after pulmonary rehabilitation (PR) – which she presented at the ERS Congress. This is the poster.

Roxy poster pre post PR2She measured breathing patterns in 20 patients with chronic respiratory disease (14 with COPD, 6 with bronchiectasis) before and after a 6-week out-patient pulmonary rehabilitation programme. We saw no changes in any of the parameters of breathing pattern (timing, volume, regional contribution) that we analysed before and after PR. Some possible reasons for this are:

  • Breathing pattern parameters are not very responsive to change
  • The PR programme that we studied lacked sufficient intensity to induce a change in breathing
  • This sample of patients had no ‘room for improvement’ in their resting breathing patterns – for example, their baseline breathlessness (assessed using Borg scores) was already very low

So, as is very common in research, we now have more questions than answers – but we plough on! We have recently welcomed a new physiotherapy PhD student (Panos Sakkatos) who holds the first ever joint Wessex Medical Trust/ British Lung Foundation scholarship to permit him to study the usefulness of breathing patterns as an outcome measure over the next four years. So he will build on what we know already, and take it forwards.

breathe in

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Waiting for death

Death inevitably comes to every living thing, but we rarely talk much about it, or share our feelings about it. I have seen many deaths, but it is still a massive mystery to me. I am writing this as I wait for death to come into my house. During my life, as well as seeing many patients die in clinical environments, I have also had to bear the much more personal deaths of my brother and both my parents. Today will bring a much ‘lesser’ death in the eyes of most – a 3 month old chicken, known on Twitter as Moxie the MiniChick – one of 12 hatched under a pet hen called Speckles. Her first brood, and all 12 hatched and survived – which apparently is an incredibly rare feat.

MC4

MiniChick was absolutely fine for the first couple of weeks, but then became listless and unwell, and my farming friends helpfully offered a dispatching service. I chose to ignore them and fed MiniChick by hand for a few days.

MC1

Amazingly there was a seemingly full recovery, and for the last couple of months MiniChick has thrived and although small (possibly with bantam genes) has feathered up like the others, and seemed to be ‘out of the woods’ and set for a normal life.

MC3 MC5

But about 3 days ago Moxie was taken ‘unwell’ – all sick chickens (from whatever cause) have a characteristic look i.e. standing alone looking droopy and hunched. So I put MiniChick into a separate hutch on the grass, and offered tasty treats and water at regular intervals. There has been a slow but persistent downwards progression towards death. A proper farming person would have ended it by now, but I am way too soft for that. So as I write I have a small dying bird in my kitchen, and inevitably this reminds me of all the other deaths I have seen.

Some deaths are so sudden and unexpected they leave you shocked and bewildered by their unfairness. Others are much slower, and it is these slower ones that I find hardest to bear. Watching another life gradually ebb away is impossibly sad. Even though I know this moment is not about me, I have the selfish wish that death would come quickly, because that would be easier for me. I have this awful inner emotional conflict of dreading the loss and pain to come, while wishing desperately for it to be all over as fast as possible, which leads to nagging guilt at being so selfish. Death is exhausting for the living.

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Breathing pattern: every breath you take

Respiration_clip_image008Breathing is unlike our other body functions because it is under both voluntary and involuntary control. While breathing is predominantly regulated by the brain stem and is responsive to the body’s demands, breathing is also very responsive to any changes in our mental state such as emotion, fear and anxiety. Although we do have some control over our breathing, this control is only within specific boundaries. For example, you can choose to hold your breath whenever you want, but you can only do so for a finite period of time before you have to let it go. Individual breathing pattern is the result of a complex mix of physical, physiological and psychological factors. This piece is a description of what we understand by the phrase ‘breathing pattern’.

Healthy resting breathing has an active inspiratory expansion phase during which muscles like the diaphragm contract, followed by a passive relaxation phase. It is generally accepted that changes in breathing pattern can indicate respiratory problems. However, although the phrase ‘breathing pattern’ is a term frequently used by respiratory clinicians, there is no consensus regarding its definition, and various respiratory parameters have been used to characterise ‘normal’ breathing pattern. The main elements of breathing pattern are timing, volume, rhythmicity (regularity/variability), and chest wall movement. But ‘normal’ limits for many of the parameters of breathing pattern have never been rigidly defined. Some of these elements are quantifiable at the bedside, such as respiratory rate – which can be counted in terms of breaths per minute (bpm). Other elements, such as breathing rhythm, and chest wall movement, have historically relied on more subjective, qualitative interpretation at the bedside, or the use of complex laboratory-based equipment.

Timing elements

Respiratory rate is commonly used during clinical monitoring. A wide range of ‘normal’ respiratory rates have been documented. One early study reported the range to be from 5 to 22 breaths per minute (bpm) in healthy resting adults (Dejours et al 1966). These findings were recorded during observational assessments of chest wall movements over a one minute period. Clinically, an estimate of respiratory rate is often obtained by counting the number of breaths in 15 seconds and multiplying by four. While this method is relatively quick and easy to perform, it is open to error, particularly if the breathing pattern is irregular. It has been suggested that respiratory rate is a ‘neglected’ vital sign because changes in respiratory rate can be predictive of ability to be separated from mechanical ventilation (weaning), or associated with the onset of disease exacerbation. In a study by Yanez et al (2012) of 89 patients with COPD, respiratory rate was reported to increase from an average of 15 bpm to 19 bpm over the five days preceding an exacerbation in 21 out of 30 patients (70%) who had an exacerbation.

Inspiratory/expiratory timing

Inspiratory time is the time it takes for air to be breathed into the lungs, whereas expiratory time is the time it takes for air to be breathed out. A breath cycle is the sum of inspiratory time, expiratory time and any pauses. There are no published normal data for timings, but there is a consensus that the ‘normal’ ratio for inspiration to expiration (I:E ratio) is 1:2 or 1:3 – for example, if someone breathes in for 1.5 seconds and out for 4.5 seconds, then the ratio is 1.5 to 4.5 or 1:3. In people with expiratory airflow obstruction (such as occurs in COPD), the expiratory time is frequently prolonged. This results in lower I:E ratios, such as 1:4 or 1:5. People with COPD often have longer expiratory times because the airways obstruction makes it more difficult to breathe out. The extent of airways obstruction is traditionally assessed using spirometric lung function tests (such as FEV1% of predicted).

Accurate measurements of inspiration and expiration time are not readily performed at the bedside, and have primarily been studied in an intensive care setting, during weaning from mechanical ventilation, or during laboratory based studies.  Unlike respiratory rate, there is little information regarding ‘normal’ values for respiratory timing components. So it is uncertain if/how these parameters alter over time, with either disease progression or therapeutic intervention.

Volume elements

Tidal volume refers to the volume of air displaced during inspiration and expiration. Resting tidal volume is the volume of air displaced during quiet breathing at rest. Assessments of tidal volume are often qualitatively assessed at the bedside (shallow or deep breaths). Tidal volume can be assessed quantitatively using various instruments, but most require a mouthpiece or facemask to provide a tight seal over the airway. A variety of ‘normal’ ranges for tidal volume have been documented with the major sources of variability being attributable to gender, age, body size and the instrument used to estimate volume (those using a mouthpiece, or noninvasive instruments).

Chest wall movements

In healthy adults, movements of the ribcage and abdomen are synchronised and both move outwards during inspiration. This synchrony can sometimes be lost, so that the ribcage moves inwards during inspiration. A lack of co-ordination between the ribcage and abdominal compartments was first documented in the in 1920s by Charles Franklin Hoover. ‘Hoover’s sign’ has since been used to indicate the flattening of the diaphragm secondary to hyperinflation in patients with COPD and other conditions. In healthy people, ribcage movement is greater than abdominal movement when standing or sitting (contributing roughly 80% of the total movement). When you lie down there is more abdominal movement (around 60% of the total). These percentages vary with age and with gender.

Breathing rhythm

There is a general perception amongst clinicians that ‘normal’ breathing is steady and regular, while ‘abnormal’ breathing is irregular and more variable. There are specific well known rhythms such as Cheyne-Stokes breathing that support this view. Cheyne-Stokes breathing is a distinctive pattern often seen in patients with end stage heart failure, characterised by periods of rapid breathing, followed by intermittent periods of not breathing (known as apnoea).

However, it is not that straightforward. Some studies have suggested that too low breathing pattern variability is also associated with respiratory problems, and that there is actually an optimal level of variability in good health (a bit like heart rate variability) – not too high, not too low. In a weaning trial (removing people from a mechanical ventilator) it was found that those with higher variability in breathing timing and volume were more likely to be successfully weaned than those who were not (Wysocki et al. 2006). Reduced tidal breathing variability has also been associated with some respiratory diseases (Brack et al 2002). Abnormal breathing patterns are a key area of research for me, particularly those associated with overbreathing (dysfunctional breathing patterns) in asthma.

Measuring breathing pattern is tricky. Observation is obviously subjective. The gold standard kit for measuring and quantifying breathing flow (and hence volume), and timing is the pneumotachograph. But studies have repeatedly shown that the use of face masks and mouthpieces, that have to be used with systems like the pneumotachograph, are associated with an increase in tidal volume and a reduction in respiratory rate, so called ‘instrument-induced’ changes. However, even the use of ‘non-invasive’ respiratory monitoring devices, like the catchily named ‘respiratory inductive/ inductance plethysmography’ kit can alter breathing pattern, just through an individual’s awareness of being monitored.

As is all too common with objective measurement devices, nothing is perfect. So why do we keep trying? Because we are looking for simple, noninvasive, patient-acceptable ways to monitor breathing problems, and to determine the effects of interventions designed to ‘improve’ breathing patterns. Even though some elements of breathing pattern have a high level of variability between different individuals, we are finding that some components of breathing pattern are more consistent within individuals, and therefore could be useful for monitoring respiratory health over time. Onwards.

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References

Brack et al (2002) Dyspnea and Decreased Variability of Breathing in Patients with Restrictive Lung Disease. American Journal of Respiratory and Critical Care Medicine 165(9): 1260-1264

Wysocki et al (2006) Reduced breathing variability as a predictor of unsuccessful patient separation from mechanical ventilation. Critical Care Medicine, 34, 2076-2083.

Yanez et al (2012) Monitoring breathing rate at home allows early identification of COPD exacerbations. Chest 142(6):1524–1529

 

 

 

 

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Grant application timelines: the myth and the reality

In my Faculty there is a procedural flowchart for ‘The grant application timeline’. I am sure that mine is not the only department to create these idealised pathways. This is ours:

Grant timeline

As you will see, these procedures start 8 weeks prior to the submission deadline with ‘initial costs’ one week into this timeline. To achieve this, you would need to have already written the protocol in full. You can’t estimate costs until you know exactly what you plan to do. So, while this timeline is a lovely idea in theory, I have never managed to achieve it myself.

As an example, I was recently involved in submitting an invited Expression of Interest to the NIHR HTA. The email invitation arrived on March 24th. The submission deadline was April 27th (with Easter in the middle). So this, dear reader, is the true timeline that we followed:

calendar-schedule

My Diary of a Grant Application

4 weeks before deadline – Call comes out for applications for funding. Cool, relaxed conversations by email within team. Seems like a good idea. What shall we do? Let’s go for it.

3 weeks before deadline – Thought for the day: I guess we should get something down on paper. I kickstart a protocol and send to Partner-in-Crime who picks up ball and runs hard. Right, first draft ready to send round team. Good work.

2 weeks before deadline – Frenetic activity. Contact: RDS team, PPI team, Health economics team, Statistics team et al. What shall we do about costings? We can’t do them properly until the protocol is agreed. Hmm. It’s only the outline phase. Think of a number.

 1 week before deadline – Nearly sorted. Looking good. All in hand. Partner-in-Crime heads off abroad in relaxed mode. Few small details to iron out. Leave it with me.

4 days before deadline – Ping! Email comes in from one co-applicant (aka The Wise One) pointing out serious flaws that need addressing. Dither. Do we pull out or try and put it right? Team keen to go ahead – but Partner-in-Crime still abroad so onus of rewrite is down to me. Tsunami of emails and telephone calls around team members.

3 days before deadline – 8.30 am: Animated telephone conversation with The Wise One – tons of genuinely useful advice that I try to write down as he speaks. Wish I had mastered short hand. Next 8 hours spent writing. Drafts sent back and forth. Further telephone conversations. Conference call includes Partner-in-Crime. The Wise One is finally happy with design and text. Sample size still an issue. Email tsunami continues around team.

2 days before deadline – Saturday – Partner-in-Crime on way back to UK. Promises to pick up final bits. Email Partner-in-Crime with ‘List of Things That Still Need to be Done’. This includes: 1) Sort out references/ citations, as I have jiggered these up through rewriting the text 2) Agree final sample size with statistician after agreed design change 3) Check my cost – ahem – estimates. Emails still swirling round team arguing terminology. Can we call it a superiority trial if we are using a t test with a two-sided significance level? And so on. I ignore these. I am out with my dog.

24 hours before deadline – Sunday – Spend whole day nervously checking iPhone every few minutes for emails from Partner-in-Crime. He completes my list of tasks and sends back to me for final proofread. I discover he has also made changes to text already approved by The Wise One. I change some of them back. Ha.

12 hours before deadline – Final email exchange with Partner-in-Crime who tells me to hit button when ready. Spend another two hours double, double-checking tiny details online.

Press SUBMIT and cross fingers.

Partner-in-Crime emails to say he has had confirmatory email of submission.

……and relax…..

Sigh-of-Relief-BACK-ON-TRACK

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How to choose a journal to publish your research: 5 top tips

journalsCongratulations! You have completed your research. The data are all collected and analysed. You may have written up some reports for your funders, and /or your educational course. Now you want to publish your findings. But where, and how? The question on Twitter from @awgilbert11 this week was an interesting one:

Gilbert twitter

 

 

 

 

– not least because it implies that you actually have a choice. Unfortunately, pragmatism often rules, so it may be less of a ‘free choice’ and more of a ‘What can I afford?’ and ‘Where am I most likely to be successful?’ decision.

Create key messages – If your research was being carried out for a Masters or *Doctorate, you will first have to work out how many papers might be written from it. It is likely that there will be more than one story to tell. Discuss this with colleagues/ supervisors, and work out a plan. Once you have decided on the focus of the first paper you want to write, your next task is to distil the key messages you want to get across. Write these down as bullet points and keep them in mind, not only while writing the paper, but while selecting the journals to approach.

[* If you have been doing a PhD, then ideally you should have been producing papers as you progress, not waiting until the end – but that’s another blog]

Tip 1: DO NOT write a paper and then think: “Hmm, now where can I send this?” Choose the journal FIRST – then write the paper to fit the journal.

Open Access journal or ‘other’? – At one time there was a clear separation between Open Access journals and the rest. This is gradually becoming less clear. Open access versions of existing ‘traditional’ journals are now springing up all over the place. Since the last Research Excellence Framework exercise, the Higher Education Funding Council for England (HEFCE) have issued a new policy requiring all publications to be open access. This can be achieved through various ways, not just through publishing in Open Access journals.

hefceposter

Some advantages of the Open Access journals are the speed with which they can publish and the wider audiences they reach. Disadvantages are the (sometimes hefty) costs usually demanded, and the perception that they are ‘less prestigious’ than more traditional journals. ‘Nature’ recently published some research into the impact of Open Access journals and found that:

“Open Access itself does not necessarily equate to more citations in these journals – nor does it equate to fewer”

They concluded:  “Open Access journals can have similar impact to other journals, and prospective authors should not fear publishing in these journals merely because of their access model. Furthermore, it does not appear that expansion of potential readership in itself will necessarily transform the impact of a journal.”

Tip 2: Choose an Open Access journal if it is the right target for your work – not because you think it will get more citations.

Journal choice – Once you have decided on the key messages from your research, then you should decide who would be most interested in knowing them. Are the messages clinical? Or technical? Or service-related? Or methodological? And so on. If they are clinical, who are they aimed at: All healthcare professionals? Medics? AHPs? Nurses? If AHPs – is it all AHPs? Physios only? Are the messages generic or very specialised? If they are for physios, are they for Musculoskeletal/ Neuro/ Respiratory? For Adults/ Paeds?

The more specialised your key messages, the smaller your target audience becomes and the less choice you will have – but these days there seems to be a journal for pretty much everything and everyone! However, if you have ambitions to get into the ‘best’ journals, your messages and style will need to fit their readership.

You will have had to conduct a literature review prior to doing your research, as part of getting funding or submitting to an Ethics committee. Which journals provided most of the sources you accessed and cited? These may be a good place to start.

Tip 3: Look back at the literature review you wrote for the original research protocol. Make a list of the journals you have cited most often.

Research the journals – Once you have created a list of possible journals, then go to selecting-the-right-journal-for-my-recent-papertheir webpages. Look for recent similar articles to the one you propose to write, in terms of subject area and scope. If there are none, this may not be the right journal for you. Check their current remit (‘Aims and Scope’/ ‘About the Journal’). This is essential because journals change over time. New editors can have different priorities. Just because they published qualitative work in the past, does not mean they still do. Reading the Aims and Scope section will let you know if your ideas fit with that journal’s readership.

Read the ‘Information for Authors’ sections very carefully. Look especially for restrictions, such as specific types of article that may not be accepted. Check permitted word length – a tight word count may be difficult for you to achieve for some types of article without significant pruning. Check for publication fees. If you have no budget, these may mean you avoiding that journal.

Tip 4: Read the Journal ‘Information for Authors’ section with a forensic eye for detail the most common avoidable reason for rejection is lack of fit with the journal’s stated aims and scope.

Impact factor – The impact factor is a measure reflecting the average number of citations to articles. It is taken to be a measure of the relative importance of a journal within its field, with journals of higher journal impact factors deemed to be more important than those with lower ones. There are several lists of Journal Impact Factors on the web. But impact factors are not the only way to judge a journal and are not without critics, see here and here. Nevertheless, they remain a target for many Higher Education institutions, with one eye always on the next Research Excellence Framework submission.

Tip 4: Look at journal impact factors, but also consider size of readership and profile of previous contributors

Timing – Are you in a hurry to publish? If so, consider the journal’s turnaround times. Look to see how large the gaps between submission and publication are (often put on first page of published articles). A monthly journal will be speedier than a quarterly/ yearly journal. Open access can be speedier still. Some journals have an online version that comes out as soon as the paper is accepted, and before the paper version. It still counts as being ‘published’.

Tip 5: If you need rapid publication, go for Open Access or a journal with at least 12 issues a year.

There are several resources on the web to help you choose a journal.  I recommend looking at this slideshow by Prof Simon Haslett, which covers a lot of useful information about publishing your research.

publishing1

 

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Statistical significance and clinical importance

success-or-significanceWhy do we do physiotherapy research?

Lots of answers are possible (both sensible and sarcastic), but in general it is to find answers to research questions and to test hypotheses. Ultimately we want to know if, or how, we should change our clinical practice for the benefit of patients. When researchers report findings, as a clinician you have to make a judgement: a) do I trust these results? b) are these results meaningful for the patients I see? Trusting results requires you to assess the design and methods used for validity and robustness of approach. If you are not sure how to do this, this series of papers by Trish Greenhalgh is an excellent place to start. This blog piece is more about the second point: how do I know if the results I read are meaningful for patients beyond those in the study?

Statistical significance 

Research studies are carried out with samples of people intended to be representative of the wider population under scrutiny. Sometimes they are, sometimes they are not. If sample sizes are very small, the chances of them NOT being representative increases. Even if sample sizes are large, just by chance they still could be unrepresentative. Statistical significance quantifies the probability that any finding was by chance alone.

Hypothesis testing is confusing. If you want to show that a treatment has an effect, you actually start by assuming there are NO treatment effects. This is the null hypothesis. In a hypothesis test you assume the null is true, and use that assumption to build a case against it being true. So, if you want to see if one form of physiotherapy is superior to another, you start by assuming there will be no differences between them. The p value will give you some evidence as to whether you can or cannot reject your null hypothesis. By convention we use a 5% level (p<0.05) to enable us to declare that something is or is not statistically significant – although you could actually set any level you wanted. Setting the level at 5% means that if you were to repeat the same study 100 times, then by chance alone you would get the same results 5 times out of that 100. And it means that by accepting the result as ‘true’ you could be wrong up to 5 times out of 100. Statistical significance is all about the probability of detecting differences, and tells you nothing about the size, importance or direction of any differences seen. I have seen students squeak with excitement when a p value is tiny (p<0.0001), mistakenly thinking it means the observed difference between groups must be large and important. On the other hand, I have seen students depressed because the p value is just outside the cut-off (p=0.056) and want to write about ‘nearly significant’ results. See Matthew Hankins’ excellent blog on this topic and why you should avoid this temptation. If you are on Twitter you can check out the #stillnotsignificant hashtag for many Tweets about the issue.

Recently there has been much debate about the overuse of, and over reliance on, p values in medical literature. You can watch a YouTube video by Geoff Cumming called ‘The dance of the p values’ about this topic. The issue has even led some journals to consider banning p values from contributors’ research papers, in favour of more descriptive statistics, or alternative approaches such as Bayesian analysis. But I suspect it will be a while, if ever, before all mainstream medical journals embrace this approach wholesale. In the meantime, many journals already require the use of confidence intervals to supplement p values, to add further information to help the reader decide whether or not to change practice. The following section in quote marks is taken from ‘Confidence Interval or P Value’

Confidence Intervals

“The confidence interval is a range of values calculated by statistical methods which includes the desired true parameter (for example, the arithmetic mean, the difference between two means, the odds ratio etc.) with a probability defined in advance (coverage probability, confidence probability, or confidence level). The confidence level of 95% is usually selected. This means that the confidence interval covers the true value in 95 of 100 studies performed. The advantage of confidence limits in comparison with p-values is that they reflect the results at the level of data measurement.” So, for example, the lower and upper limits of a difference in peak flow measurements would be given in litres per minute (L/min). A confidence interval calculated for a measure of treatment effect shows the range within which the true treatment effect is likely to lie (subject to a number of assumptions). Wide confidence intervals usually mean the sample size was too small, and make interpretation of findings difficult.

Clinical importance

In the past, the only way to assess the clinical importance of research findings was to use your own judgement. You read the paper, saw it was statistically significant, or not – and then tried to work out if the patients in the study were like ones who you saw, and decide if the differences seen in the study sample were relevant to your patients. Dissatisfaction with the reliance on statistical significance and p values has led to the concept of clinically important differences. “A clinically important difference represents a change that would be considered meaningful and worthwhile by the patient such that he/ she would consider repeating the intervention if it were his/her choice to make again. The minimum clinically important difference (MCID) is a threshold value for such a change. Any amount of change greater than the MCID threshold is considered to be meaningful or important.” (Understanding the minimum clinically important difference: a review of concepts and methods). So, the MCID is the smallest change that is important to patients, and there are two broad approaches to its calculation: anchor based approaches, and distribution based approaches. For a detailed account of these approaches see here. Within physiotherapy there has been work in recent years to calculate the MCID for our more commonly used outcome measures. But one problem with the MCID is that different approaches give different answers, and the figures are dependent on the initial baseline for patients – so may not be generalisable across patient groups. For this reason it is becoming more common to see a range for the MCID rather than an absolute value. For example in my own field (respiratory) the 6 minute walk test (6MWT) is said to have a MCID range of between 25 and 33 m for patients with chronic respiratory disease.

But there are issues with the MCID, and not everyone in physiotherapy is happy about using them without caution because:

  • MCID scores reported as single point estimate based upon the average score of a group lack associated confidence intervals representative of the wide distribution of actual change score values.
  • Use of a single point estimate runs the risk of misclassifying patients as not improved when, in fact, they have.

So, although the MCID may seem like the clinician’s answer to the question: ‘How do I know if this is clinically important?’ – it is by no means perfect.

Take home message

If a study has a very large sample size, results may be found to be statistically significant, but the measured differences may be too small to be clinically important. On the other hand, if a study is small, the results may not be statistically significant because the study was too small to detect the difference (described as underpowered), but the measured difference may look large, and seem to you to be clinically relevant. It would then be sensible to repeat the small study with a larger sample, to make sure the original small sample were truly representative of the population, and the original observed differences are still seen. Remember how those p values can dance!

Snoopy

Disclaimer

I am not a statistician. I am a physiotherapist and a researcher. To the best of my knowledge this content is correct, but if any statisticians happen upon this page and spot any errors, please let me know and I will amend accordingly. it was inspired by a query from @_JoeMiddleton on Twitter. He encapsulated the whole thing very neatly in 140 characters!

Twitter 2

References

BMJ papers on ‘How to Read a Paper’ by Trish Greenhalgh http://www.bmj.com/about-bmj/resources-readers/publications/how-read-paper

Still not significant by Matthew Hankins https://mchankins.wordpress.com/2013/04/21/still-not-significant-2/

Dance of the p values by Geoff Cumming https://www.youtube.com/watch?v=5OL1RqHrZQ8

Psychology journal bans significance testing (2015) Steven Novella http://www.sciencebasedmedicine.org/psychology-journal-bans-significance-testing/

Confidence Interval or P-Value? (2009) Jean-Baptist du Prel et al Dtsch Arztebl Int http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2689604/

Understanding the minimum clinically important difference: a review of concepts and methods (2007) Copay AG et al The Spine Journal http://www.thespinejournalonline.com/article/S1529-9430(07)00052-6/abstract?cc=y

An official systematic review of the European Respiratory Society/American Thoracic Society: measurement properties of field walking tests in chronic respiratory disease. (2014) by Sally Singh et al. European Respirator Journal vol. 44:1447-1478 http://erj.ersjournals.com/content/44/6/1447.full

Why the MCID is no good for Physical Therapy by Chad Cook  http://www.iaopt.org/pdf/part_4_kaiser_presentation_cook.pdf

 

 

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