Anne E. Holland

An official European Respiratory Society/American Thoracic Society technical standard: field walking tests in chronic respiratory disease

Field walking tests are commonly employed to evaluate exercise capacity, assess prognosis and evaluate treatment response in chronic respiratory diseases. In recent years, there has been a wealth of new literature pertinent to the conduct of the 6-min walk test (6MWT), and a growing evidence base describing the incremental and endurance shuttle walk tests (ISWT and ESWT, respectively). The aim of this document is to describe the standard operating procedures for the 6MWT, ISWT and ESWT, which can be consistently employed by clinicians and researchers. The Technical Standard was developed by a multidisciplinary and international group of clinicians and researchers with expertise in the application of field walking tests. The procedures are underpinned by a concurrent systematic review of literature relevant to measurement properties and test conduct in adults with chronic respiratory disease. Current data confirm that the 6MWT, ISWT and ESWT are valid, reliable and responsive to change with some interventions. However, results are sensitive to small changes in methodology. It is important that two tests are conducted for the 6MWT and ISWT. This Technical Standard for field walking tests reflects current evidence regarding procedures that should be used to achieve robust results. Technical Standard document: standard operating procedures for the 6MWT, ISWT and ESWT in chronic respiratory disease http://ow.ly/Bq2B9

Updating the minimal important difference for six-minute walk distance in patients with chronic obstructive pulmonary disease.

OBJECTIVE To establish the minimal important difference (MID) for the six-minute walk distance (6MWD) in persons with chronic obstructive pulmonary disease (COPD). DESIGN Analysis of data from an observational study using distribution- and anchor-based methods to determine the MID in 6MWD. SETTING Outpatient pulmonary rehabilitation program at 2 teaching hospitals. PARTICIPANTS Seventy-five patients with COPD (44 men) in a stable clinical state with mean age 70 years (SD 9 y), forced expiratory volume in one second 52% (SD 21%) predicted and baseline walking distance 359 meters (SD 104 m). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Participants completed the six-minute walk test before and after a 7-week pulmonary rehabilitation program. Participants and clinicians completed a global rating of change score while blinded to the change in 6MWD. RESULTS The mean change in 6MWD in participants who reported themselves to be unchanged was 17.7 meters, compared with 60.2 meters in those who reported small change and 78.4 meters in those who reported substantial change (P=.004). Anchor-based methods identified an MID of 25 meters (95% confidence interval 20-61 m). There was excellent agreement with distribution-based methods (25.5-26.5m, kappa=.95). A change in 6MWD of 14% compared with baseline also represented a clinically important effect; this threshold was less sensitive than for absolute change (sensitivity .70 vs .85). CONCLUSIONS The MID for 6MWD in COPD is 25 meters. Absolute change in 6MWD is a more sensitive indicator than percentage change from baseline. These data support the use of 6MWD as a patient-important outcome in research and clinical practice.

Short term improvement in exercise capacity and symptoms following exercise training in interstitial lung disease

Background: Interstitial lung disease (ILD) is characterised by exertional dyspnoea, exercise limitation and reduced quality of life. The role of exercise training in this diverse patient group is unclear. The aims of this study were to establish the safety of exercise training in ILD; its effects on exercise capacity, dyspnoea and quality of life; and whether patients with idiopathic pulmonary fibrosis (IPF) had similar responses to those with other types of ILD. Methods: 57 subjects with ILD (34 IPF) were randomised to receive 8 weeks of supervised exercise training or weekly telephone support. The 6 min walk distance (6MWD), incremental exercise test, modified Medical Research Council (MRC) dyspnoea score and Chronic Respiratory Disease Questionnaire (CRDQ) were performed at baseline, following intervention and at 6 months. Results: 80% of subjects completed the exercise programme and no adverse events were recorded. The 6MWD increased following training (mean difference to control 35 m, 95% CI 6 to 64 m). A significant reduction in MRC score was observed (0.7 points, 95% CI 0.1 to 1.3) along with improvements in dyspnoea (p = 0.04) and fatigue (p<0.01) on the CRDQ. There was no change in peak oxygen uptake; however, exercise training reduced heart rate at maximum isoworkload (p = 0.01). There were no significant differences in response between those with and without IPF. After 6 months there were no differences between the training and control group for any outcome variable. Conclusions: Exercise training improves exercise capacity and symptoms in patients with ILD, but these benefits are not sustained 6 months following intervention. Trial registration number: NCT00168285

The six-minute walk test: a useful metric for the cardiopulmonary patient

Measurement of exercise capacity is an integral element in assessment of patients with cardiopulmonary disease. The 6‐min walk test (6MWT) provides information regarding functional capacity, response to therapy and prognosis across a range of chronic cardiopulmonary conditions. A distance less than 350 m is associated with increased mortality in chronic obstructive pulmonary disease, chronic heart failure and pulmonary arterial hypertension. Desaturation during a 6MWT is an important prognostic indicator for patients with interstitial lung disease. The 6MWT is sensitive to commonly used therapies in chronic obstructive pulmonary disease such as pulmonary rehabilitation, oxygen, long‐term use of inhaled corticosteroids and lung volume reduction surgery. However, it appears less reliable to detect changes in clinical status associated with medical therapies for heart failure. A change in walking distance of more than 50 m is clinically significant in most disease states. When interpreting the results of a 6MWT, consideration should be given to choice of predictive values and the methods by which the test was carried out.

An official systematic review of the European Respiratory Society/American Thoracic Society: measurement properties of field walking tests in chronic respiratory disease

This systematic review examined the measurement properties of the 6-min walk test (6MWT), incremental shuttle walk test (ISWT) and endurance shuttle walk test (ESWT) in adults with chronic respiratory disease. Studies that report the evaluation or use of the 6MWT, ISWT or ESWT were included. We searched electronic databases for studies published between January 2000 and September 2013. The 6-min walking distance (6MWD) is a reliable measure (intra-class correlation coefficients ranged from 0.82 to 0.99 in seven studies). There is a learning effect, with greater distance walked on the second test (pooled mean improvement of 26 m in 13 studies). Reliability was similar for ISWT and ESWT, with a learning effect also evident for ISWT (pooled mean improvement of 20 m in six studies). The 6MWD correlates more strongly with peak work capacity (r=0.59–0.93) and physical activity (r=0.40–0.85) than with respiratory function (r=0.10–0.59). Methodological factors affecting 6MWD include track length, encouragement, supplemental oxygen and walking aids. Supplemental oxygen also affects ISWT and ESWT performance. Responsiveness was moderate to high for all tests, with greater responsiveness to interventions that included exercise training. The findings of this review demonstrate that the 6MWT, ISWT and ESWT are robust tests of functional exercise capacity in adults with chronic respiratory disease. Systematic review: support for use of the 6MWT, ISWT and ESWT in adults with chronic respiratory disease http://ow.ly/Bq2Mz

Motivational interviewing to increase physical activity in people with chronic health conditions: a systematic review and meta-analysis

Objective: A systematic review and meta-analysis of randomized controlled trials to determine if motivational interviewing leads to increased physical activity, cardiorespiratory fitness or functional exercise capacity in people with chronic health conditions. Data sources: Seven electronic databases (MEDLINE, PsychINFO, EMBASE, AMED, CINHAL, SPORTDiscus and the Cochrane Central Register of Controlled trials) were searched from inception until January 2014. Trial selection: Two reviewers independently examined publications for inclusion. Trials were included if participants were adults (>18 years), had a chronic health condition, used motivational interviewing as the intervention and examined physical activity, cardiorespiratory fitness or functional exercise capacity. Data extraction: Two reviewers independently extracted data. Risk of bias within trials was assessed using the Physiotherapy Evidence Database Scale. Data synthesis: Meta-analyses were conducted with standardized mean differences and 95% confidence intervals (CIs) were calculated. The Grades of Recommendation, Assessment, Development and Evaluation approach was used to evaluate the quality of the evidence. Results: Eleven publications (of ten trials) were included. There was moderate level evidence that motivational interviewing had a small effect in increasing physical activity levels in people with chronic health conditions relative to comparison groups (standardized mean differences = 0.19, 95% CI 0.06 to 0.32, p = 0.004). Sensitivity analysis based on trials that confirmed treatment fidelity produced a larger effect. No conclusive evidence was observed for cardiorespiratory fitness or functional exercise capacity. Conclusion: The addition of motivational interviewing to usual care may lead to modest improvements in physical activity for people with chronic health conditions.

An Official American Thoracic Society/European Respiratory Society Policy Statement: Enhancing Implementation, Use, and Delivery of Pulmonary Rehabilitation

RATIONALE Pulmonary rehabilitation (PR) has demonstrated physiological, symptom-reducing, psychosocial, and health economic benefits for patients with chronic respiratory diseases, yet it is underutilized worldwide. Insufficient funding, resources, and reimbursement; lack of healthcare professional, payer, and patient awareness and knowledge; and additional patient-related barriers all contribute to the gap between the knowledge of the science and benefits of PR and the actual delivery of PR services to suitable patients. OBJECTIVES The objectives of this document are to enhance implementation, use, and delivery of pulmonary rehabilitation to suitable individuals worldwide. METHODS Members of the American Thoracic Society (ATS) Pulmonary Rehabilitation Assembly and the European Respiratory Society (ERS) Rehabilitation and Chronic Care Group established a Task Force and writing committee to develop a policy statement on PR. The document was modified based on feedback from expert peer reviewers. After cycles of review and revisions, the statement was reviewed and formally approved by the Board of Directors of the ATS and the Science Council and Executive Committee of the ERS. MAIN RESULTS This document articulates policy recommendations for advancing healthcare professional, payer, and patient awareness and knowledge of PR, increasing patient access to PR, and ensuring quality of PR programs. It also recommends areas of future research to establish evidence to support the development of an updated funding and reimbursement policy regarding PR. CONCLUSIONS The ATS and ERS commit to undertake actions that will improve access to and delivery of PR services for suitable patients. They call on their members and other health professional societies, payers, patients, and patient advocacy groups to join in this commitment.

Small changes in six-minute walk distance are important in diffuse parenchymal lung disease

UNLABELLED The aim of this study was to determine the minimal important difference for the six-minute walk distance in people with diffuse parenchymal lung disease. METHODS Forty-eight subjects (24 idiopathic pulmonary fibrosis) undertook the six-minute walk test before and after an 8-week exercise program. The minimal important difference was calculated using a distribution-based and an anchor-based method. A global rating of change scale was used as the external criterion to judge patients as clinically unchanged or changed. RESULTS The mean change in six-minute walk distance in improved subjects was 50.0 m, compared to 4.0 m in unchanged subjects and a reduction of 64.3 m in those classified as worse (p<0.001). The receiver operating characteristic curve indicated a cut-off value for meaningful change of 30.5 m (area under the curve 0.89, 95% confidence interval 0.81-0.98) whilst the standard error of the mean method indicated a value of 33 m. Similar values were obtained when only subjects with idiopathic pulmonary fibrosis were included (29 and 34 m, respectively). CONCLUSIONS Small differences in six-minute walk distance, in the range 29-34 m, may be clinically significant for people with diffuse parenchymal lung disease.

Do Activity Levels Increase After Total Hip and Knee Arthroplasty

BackgroundPeople with osteoarthritis (OA) often are physically inactive. Surgical treatment including total hip arthroplasty or total knee arthroplasty can substantially improve pain, physical function, and quality of life. However, their impact on physical activity levels is less clear.Questions/purposesWe used accelerometers to measure levels of physical activity pre- and (6 months) postarthroplasty and to examine the proportion of people meeting the American Physical Activity Guidelines.MethodsSixty-three people with hip or knee OA awaiting arthroplasty were recruited from a major metropolitan hospital. Physical activity was measured using accelerometry before, and 6 months after, surgery. The ActiGraph GT1M (ActiGraph LLC, Fort Walton Beach, FL, USA) was used in this study and is a uniaxial accelerometer contained within a small activity monitor designed to measure human movement through changes in acceleration, which can then be used to estimate physical activity over time. Questionnaires were used to assess patient-reported changes in pain, function, quality of life, and physical activity. Complete data sets (including valid physical activity data) for both time points were obtained for 44 participants (70%). At baseline before arthroplasty, the activity level of patients was, on average, sedentary for 82% of the time over a 24-hour period (based on accelerometry) and self-rated as “sometimes participates in mild activities such as walking, limited shopping, and housework” according to the UCLA activity scale.ResultsThere was no change in objectively measured physical activity after arthroplasty. The majority of participants were sedentary, both before and after arthroplasty, and did not meet the American Physical Activity Guidelines recommended to promote health. This was despite significant improvements in self-reported measures of pain, function, quality of life, and physical activity after arthroplasty.ConclusionsDespite patient-reported improvements in pain, function, and physical activity after arthroplasty, objectively measured improvements in physical activity may not occur. Clinicians should incorporate strategies for improving physical activity into their management of patients after hip and knee arthroplasty to maximize health status. Future research is needed to explore the factors that impact physical activity levels in people after arthroplasty.Level of EvidenceLevel IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

A randomised controlled trial of an open lung strategy with staircase recruitment, titrated PEEP and targeted low airway pressures in patients with acute respiratory distress syndrome

IntroductionTidal volume and plateau pressure minimisation are the standard components of a protective lung ventilation strategy for patients with acute respiratory distress syndrome (ARDS). Open lung strategies, including higher positive end-expiratory pressure (PEEP) and recruitment manoeuvres to date have not proven efficacious. This study examines the effectiveness and safety of a novel open lung strategy, which includes permissive hypercapnia, staircase recruitment manoeuvres (SRM) and low airway pressure with PEEP titration.MethodTwenty ARDS patients were randomised to treatment or ARDSnet control ventilation strategies. The treatment group received SRM with decremental PEEP titration and targeted plateau pressure < 30 cm H2O. Gas exchange and lung compliance were measured daily for 7 days and plasma cytokines in the first 24 hours and on days 1, 3, 5 and 7 (mean ± SE). Duration of ventilation, ICU stay and hospital stay (median and interquartile range) and hospital survival were determined.ResultsThere were significant overall differences between groups when considering plasma IL-8 and TNF-α. For plasma IL-8, the control group was 41% higher than the treatment group over the seven-day period (ratio 1.41 (1.11 to 1.79), P = 0.01), while for TNF-α the control group was 20% higher over the seven-day period (ratio 1.20 (1.01 to 1.42) P = 0.05). PaO2/FIO2 (204 ± 9 versus 165 ± 9 mmHg, P = 0.005) and static lung compliance (49.1 ± 2.9 versus 33.7 ± 2.7 mls/cm H2O, P < 0.001) were higher in the treatment group than the control group over seven days. There was no difference in duration of ventilation (180 (87 to 298) versus 341 (131 to 351) hrs, P = 0.13), duration of ICU stay (9.9 (5.6 to 14.8) versus 16.0 (8.1 to 19.3) days, P = 0.19) and duration of hospital stay (17.9 (13.7 to 34.5) versus 24.7 (20.5 to 39.8) days, P = 0.16) between the treatment and control groups.ConclusionsThis open lung strategy was associated with greater amelioration in some systemic cytokines, improved oxygenation and lung compliance over seven days. A larger trial powered to examine clinically-meaningful outcomes is warranted.Trial registrationACTRN12607000465459