Interpretation of treatment changes in 6-minute walk distance in patients with COPD

Effect of Resveratrol on Walking Performance in Older People With Peripheral Artery Disease: The RESTORE Randomized Clinical Trial

Importance

Research shows that resveratrol, a sirtuin activator in red wine, improves exercise endurance and skeletal-muscle oxidative metabolism in animals and may enhance vascular function in humans. Resveratrol supplement sales exceed $30 million annually in the United States, but few data are available regarding its efficacy in humans.

Objective

To determine whether resveratrol, 125 mg/d or 500 mg/d, improves the 6-minute walk performance in patients with peripheral artery disease (PAD).

Design, Setting, and Participants

This parallel-design, double-blind, randomized clinical trial, called Resveratrol to Improve Outcomes in Older People With PAD (RESTORE), was conducted at Northwestern University. Sixty-six participants 65 years or older with PAD were randomized to receive a daily capsule of resveratrol, 125 mg or 500 mg, or placebo for 6 months. Participants were randomized using a randomly permuted block method stratified by baseline 6-minute walk test performance. This trial was conducted between January 1, 2015, and August 5, 2016, and data analyses were performed according to the intention-to-treat concept.

Interventions

Administration of resveratrol, 125 or 500 mg/d, or placebo once daily.

Main Outcomes and Measures

The primary outcome measure was the change in 6-minute walk distance at the 6-month follow-up. One of the secondary outcomes was change in maximal treadmill walking time. Because of the preliminary nature of the trial, the a priori power calculation used a 1-sided test with a significance level of P < .10.

Results

The 66 participants were predominantly men (45 [68%]), had a mean (SD) age of 74.4 (6.6) years, and had a mean (SD) ankle brachial index of 0.67 (0.18). Sixty-four (97%) completed follow-up. Six-month mean (SE) changes in 6-minute walk distance were 4.6 (8.1) m for the 125-mg resveratrol group, -12.8 (7.5) m for the 500-mg resveratrol group, and -12.3 (7.9) m for the placebo group (P = .07 for the 125-mg resveratrol group vs placebo; P = .96 for the 500-mg resveratrol group vs placebo). Six-month mean (SE) changes in maximal treadmill walking time were 0.5 (2.3) minutes for the 125-mg resveratrol group, -0.6 (2.1) minutes for the 500-mg resveratrol group, and 0.4 (2.1) minutes for the placebo group (P = .18 for the 125-mg resveratrol group vs placebo; P = .12 for the 500-mg resveratrol group vs placebo).

Conclusions and Relevance

The RESTORE trial found no consistent evidence that resveratrol improves walking performance in patients 65 years or older with PAD.

Trial Registration

clinicaltrials.gov Identifier: NCT02246660.

Minimum important difference of the incremental shuttle walk test distance in patients with COPD

We aimed to describe the minimum important difference (MID) of the incremental shuttle walk test (ISWT) in patients with COPD using both distribution and anchor-based methods. Two cohorts were used (n=613) with eligibility criteria of a clinical diagnosis of COPD, an FEV₁/FVC <70% and an ISWT (after familiarisation) before and after a 7-week course of pulmonary rehabilitation (PR). The MID of the ISWT using the distribution method was 36.1 m. The area under the curve to discriminate between perceived 'improvement' and 'no improvement' after PR for a change in ISWT of 35 m was 0.66 (0.58-0.73). The MID of the ISWT is therefore between 35.0 and 36.1 m.

Blood pressure response to exposure to moderate altitude in patients with COPD

Purpose

Patients with COPD might be particularly susceptible to hypoxia-induced autonomic dysregulation. Decreased baroreflex sensitivity (BRS) and increased blood pressure (BP) variability (BPV) are markers of impaired cardiovascular autonomic regulation and there is evidence for an association between decreased BRS/increased BPV and high cardiovascular risk. The aim of this study was to evaluate the effect of short-term exposure to moderate altitude on BP and measures of cardiovascular autonomic regulation in COPD patients.

Materials and methods

Continuous morning beat-to-beat BP was noninvasively measured with a Finometer^® device for 10 minutes at low altitude (490 m, Zurich, Switzerland) and for 2 days at moderate altitude (2,590 m, Davos Jakobshorn, Switzerland) – the order of altitude exposure was randomized. Outcomes of interest were mean SBP and DBP, BPV expressed as the coefficient of variation (CV), and spontaneous BRS. Changes between low altitude and day 1 and day 2 at moderate altitude were assessed by ANOVA for repeated measurements with Fisher’s exact test analysis.

Results

Thirty-seven patients with moderate to severe COPD (mean±SD age 64±6 years, FEV₁ 60%±17%) were included. Morning SBP increased by +10.8 mmHg (95% CI: 4.7–17.0, P=0.001) and morning DBP by +5.0 mmHg (95% CI: 0.8–9.3, P=0.02) in response to altitude exposure. BRS significantly decreased (P=0.03), whereas BPV significantly and progressively increased (P<0.001) upon exposure to altitude.

Conclusion

Exposure of COPD patients to moderate altitude is associated with a clinically relevant increase in BP, which seems to be related to autonomic dysregulation.

Clinical trial registration

ClinicalTrials.gov (NCT01875133).

Reliability and Validity of the 6-Minute Walk Test in Hypophosphatasia

This investigation evaluated the reliability and validity of the 6‐Minute Walk Test (6MWT) in patients with pediatric hypophosphatasia (HPP). Children (aged 6 to 12 years; n = 11), adolescents (13 to 17 years; n = 4), and adults (18 to 65 years; n = 9) completed the 6MWT at screening and baseline in two clinical studies of asfotase alfa. Test‐retest reliability of the 6MWT, evaluated with Pearson's correlation coefficients (r) for screening versus baseline, was high for children (r = 0.95; p < 0.0001), adolescents (r = 0.81; p = 0.125), and adults (r = 0.94; p = 0.0001). The most conservative minimal clinically important differences, estimated using distribution‐based methods, were 31 m (children and adults) and 43 m (adolescents). In children, the 6MWT correlated significantly with scores on measures of skeletal disease, which included the Radiographic Global Impression of Change scale (r = 0.50; p < 0.0001) and the Rickets Severity Scale (r = −0.78; p < 0.0001), such that distance walked increased as the severity of skeletal disease decreased. Significant (p < 0.0001) correlations with the 6MWT distance walked were also observed for children with scores on parent‐reported measures of disability (r = −0.67), ability to function in activities of daily living (r = 0.71 to 0.77), and parent‐reported measures of pain (r = −0.39). In adolescents and adults, 6MWT distance walked correlated significantly (p < 0.05) with measures of lower extremity function (r = 0.83 and 0.60, respectively), total pain severity (r = −0.41 and −0.36, respectively), and total pain interference (r = −0.41 and −0.49, respectively). Collectively, these data indicate that the 6MWT is a reliable, valid measure of physical functioning in patients with pediatric HPP. © 2018 The Authors. JBMR Plus Published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.

Inspiratory muscle strength training improves lung function in patients with the hypermobile Ehlers-Danlos syndrome: A randomized controlled trial

As exertional inspiratory dyspnea is a common disabling complaint in hypermobile Ehlers-Danlos syndrome (hEDS) often also known as joint hypermobility syndrome (JHS), we investigated inspiratory muscle (IM) strength in patients with hEDS, and we assessed the effects of IM training (IMT) on IM strength, lung function, and exercise capacity. A prospective evaluation of IM strength followed by a randomized controlled trial of IMT was performed in women with hEDS. Sniff nasal inspiratory pressure (SNIP) was used to routinely measure IM strength and IMT was carried out using a pressure threshold device. IM strength (main outcome), cardiopulmonary function, exercise capacity, and emotional distress of both the treated and control groups were evaluated at the start and at the end of the 6-week training period. IM strength was reduced (<80% of predicted) in 77% of patients (80/104). Lung function was normal, although 24% of patients had a higher forced expiratory vital capacity (FVC) than normal and 12% of patients had a higher total lung capacity (TLC) than normal. Both the IMT and control groups (n = 20) had similar baseline characteristics. Significant changes were noted only in the IMT group after IMT. At the end of the program, IMT improved SNIP (20%) (before: 41 ± 17 cm H₂ O [28, 53] vs. after: 49 ± 18 cm H₂ O [34;65]), six-minute walking distance (6MWD) (60 m) (455 ± 107 m [379,532] vs. 515 ± 127 m [408, 621]), and forced expiratory volume in one second (FEV1) (285 mL) (94 ± 14% pred [84,104] vs. 103 ± 11% pred [94, 112]). IM strength is significantly reduced in patients with hEDS. IMT improved IM strength, lung function, and exercise capacity. Our findings suggest that IMT should be added to usual care.

Exercise performance and symptoms in lowlanders with COPD ascending to moderate altitude: randomized trial

Objective

To evaluate the effects of altitude travel on exercise performance and symptoms in lowlanders with COPD.

Design

Randomized crossover trial.

Setting

University Hospital Zurich (490 m), research facility in mountain villages, Davos Clavadel (1,650 m) and Davos Jakobshorn (2,590 m).

Participants

Forty COPD patients, Global Initiative for Obstructive Lung Disease (GOLD) grade 2–3, living below 800 m, median (quartiles) age 67 y (60; 69), forced expiratory volume in 1 second 57% predicted (49; 70).

Intervention

Two-day sojourns at 490 m, 1,650 m, and 2,590 m in randomized order.

Outcome measures

Six-minute walk distance (6MWD), cardiopulmonary exercise tests, symptoms, and other health effects.

Results

At 490 m, days 1 and 2, median (quartiles) 6MWD were 558 m (477; 587) and 577 m (531; 629). At 2,590 m, days 1 and 2, mean changes in 6MWD from corresponding day at 490 m were −41 m (95% CI −51 to −31) and −40 m (−53 to −27), n=40, P<0.05, both changes. At 1,650 m, day 1, 6MWD had changed by −22 m (−32 to −13), maximal oxygen uptake during bicycle exercise by −7% (−13 to 0) vs 490 m, P<0.05, both changes. At 490 m, 1,650 m, and 2,590 m, day 1, resting PaO₂ were 9.0 (8.4; 9.4), 8.1 (7.5; 8.6), and 6.8 (6.3; 7.4) kPa, respectively, P<0.05 higher altitudes vs 490 m. While staying at higher altitudes, nine patients (24%) experienced symptoms or adverse health effects requiring oxygen therapy or relocation to lower altitude.

Conclusion

During sojourns at 1,650 m and 2,590 m, lowlanders with moderate to severe COPD experienced a mild reduction in exercise performance and nearly one quarter required oxygen therapy or descent to lower altitude because of adverse health effects. The findings may help to counsel COPD patients planning altitude travel.

Registration

ClinicalTrials.gov: NCT01875133

PSYCHOMETRIC PROPERTIES OF FUNCTIONAL CAPACITY TESTS IN CHILDREN AND ADOLESCENTS: SYSTEMATIC REVIEW

OBJECTIVES

To identify studies that evaluated psychometric properties of functional capacity tests in children and adolescents, and to verify which of these have satisfactory properties of measurement.

DATA SOURCES

Searches on MEDical Literature Analysis and Retrieval System Online (MEDLINE), Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Scientific Electronic Library Online (SciELO) databases without limiting period or language. Two investigators independently selected articles based on the following inclusion criteria: children and/or adolescent population (healthy or with cardiorespiratory diseases); and assessment of psychometric properties of functional capacity tests. Studies with (I) adult samples, (II) sample with neurological diseases, and (III) on reference values or prediction equations only were excluded.

DATA SYNTHESIS

From the total of 677 articles identified, 11 were selected. These evaluated the psychometric properties of the following tests: 6-minute walk test (6MWT) (n=7); 6MWT and the 3-minute step test (3MST) (n=1); and Incremental Shuttle Walk Test (ISWT) (n=3). Reproducibility and reliability were good for 6MWT and ISWT, and moderate for 3MST. The ISWT showed high validity measures for both healthy children and children with chronic respiratory disease. The validity of 6MWT varied across studies, and should be analyzed according to the health conditions of test takers. The validity of 3MST is unclear, and further studies in pediatric population are required.

CONCLUSIONS

Most studies investigated 6MWT measurement properties. Validity of 6MWT varied according to different pediatric populations. The use of 6MWT, ISWT and 3MST tests to measure clinically important changes in children and adolescents with cardiorespiratory diseases is still unclear.

Acute effects of photobiomodulation therapy (PBMT) combining laser diodes, light-emitting diodes, and magnetic field in exercise capacity assessed by 6MST in patients with COPD: a crossover, randomized, and triple-blinded clinical trial

Chronic obstructive pulmonary disease (COPD) is characterized by dyspnea, as well as musculoskeletal and systemic manifestations. Photobiomodulation therapy (PBMT) with use of low-level laser therapy (LLLT) and/or light-emitting diode therapy (LEDT) is an electrophysical intervention that has been found to minimize or delay muscle fatigue. The aim of this study was to evaluate the acute effect of PBMT with combined use of lasers diodes, light-emitting diodes (LEDs), magnetic field on muscle performance, exercise tolerance, and metabolic variables during the 6-minute stepper test (6MST) in patients with COPD. Twenty-one patients with COPD (FEV₁ 46.3% predicted) completed the 6MST protocol over 2 weeks, with one session per week. PBMT/magnetic field or placebo (PL) was performed before each 6MST (17 sites on each lower limb, with a dose of 30 J per site, using a cluster of 12 diodes 4 × 905 nm super-pulsed laser diodes, 4 × 875 nm infrared LEDs, and 4 × 640 nm red LEDs; Multi Radiance Medical™, Solon, OH, USA). Patients were randomized into two groups before the test according to the treatment they would receive. Assessments were performed before the start of each protocol. The primary outcomes were oxygen uptake and number of steps, and the secondary outcome was perceived exertion (dyspnea and fatigue in the lower limbs). PBMT/magnetic field applied before 6MST significantly increased the number of steps during the cardiopulmonary exercise test when compared to the results with placebo (129.8 ± 10.6 vs 116.1 ± 11.5, p = 0.000). PBMT/magnetic field treatment also led to a lower score for the perception of breathlessness (3.0 [1.0-7.0] vs 4.0 [2.0-8.0], p = 0.000) and lower limb fatigue (2.0 [0.0-5.0] vs 4.0 [0.0-7.0], p = 0.001) compared to that with placebo treatment. This study showed that the combined application of PBMT and magnetic field increased the number of steps during the 6MST and decreased the sensation of dyspnea and lower limb fatigue in patients with COPD.

Comparison of Effects of Endurance and Strength Training Programs in Patients with COPD

Comparisons between endurance and strength training in chronic obstructive pulmonary disease (COPD) patients have produced equivocal findings when examining physical function and health-related quality of life (HRQL). One reason for these differences may be due to individual patient responses to the different training modalities.

PURPOSE

To compare changes in physical function and HRQL in a group of COPD patients completing both an endurance and a strength training program.

METHODS

Eleven mildly diseased patients completed a three month endurance training program and, approximately 5 years later, completed a three month strength training program. Changes in 6 minute walk distance (6 MW), time to rise from a chair five times (CRT), and the total score and subscores from the SF-36 and Chronic Respiratory Disease Questionnaire (CRQ) were examined.

RESULTS

The forced expiratory volume as a percent of predicted remained relatively constant over the 5 years (61.1 ± 5.9 vs. 60.0 ± 10.3). Endurance and strength training increased 6 MW by 48.2 ± 11.2 (p = 0.008) and 39.8 ± 9.8 (p = 0.001) meters, respectively. Endurance and strength training decreased CRT by 4.8 ± 0.7 (p = 0.001) and 1.3 ± 1.2 (p = 0.056) seconds, respectively. Endurance training resulted in greater improvements in HRQL as compared to strength training.

CONCLUSION

These results show that walk distance improves as a result of participating in either an endurance or a strength training program. However, an endurance training program leads to greater improvements in both general and disease specific measures of HRQL.

Transition from Ambrisentan to Bosentan in Pulmonary Arterial Hypertension: A Single-Center Prospective Study

Background and objective: Two endothelin receptor antagonists (ETRAs), bosentan and ambrisentan, are approved for patients with pulmonary arterial hypertension (PAH). However, there is little information about the transition strategy between these two ETRAs. We aimed to evaluate the safety and efficacy from ambrisentan to bosentan. Methods: Twenty PAH patients were enrolled into the single-center, open-labelled prospective study. Echocardiogram, WHO functional class (WHO-FC), 6-minute walking distance (6MWD), right heart catheterization, and hemotology were collected. After receiving oral 5 mg ambrisentan daily initially for one year, the patients were divided into two arms: eight patients switched to bosentan, while the remaining 12 patients continued ambrisentan. Characteristics at baseline, 1-and 2-year follow-up points were compared.

RESULTS

There were no significant differences in echocardiogram, WHO-FC, hemodynamics, demographics and liver function at baseline, 1-and 2-year points in both arms. 6MWD in bosentan group was significantly shorter at baseline. But there were no significant differences of 6MWD at 1- and 2-year points.

CONCLUSIONS

It is safe for stable PAH patients to transition from ambrisentan to bosentan without hemodynamic or hematologic deterioration.

Effectiveness of a respiratory rehabilitation programme in patients with chronic obstructive pulmonary disease

OBJECTIVE

To evaluate the effectiveness of the multidisciplinary respiratory rehabilitation (RR) programme in patients with severe or very severe chronic obstructive pulmonary disease pre the RR programme, at the end of the programme and one year after the RR, measuring changes in ability to exercise (walking test), effort tolerance(forced expiratory volume (FEV1)) and health-related quality of life.

METHOD

Quasi-experimental single group design. We included patients diagnosed with severe or very severe chronic obstructive pulmonary disease (stages III and IV of the GOLD classification) who entered the rehabilitation programme for the years 2011 and 2012. Demographic data, questionnaires on general health-related quality of life (SF-36) and specific to respiratory patients (St George's Respiratory Questionnaire), FEV1% and exercise capacity test (running test 6minutes) were collected. Data were collected before the RR programme, at the end of the RR programme and a year after completing the program.

RESULTS

No significant differences in FEV1% values were observed. Regarding exercise capacity, an increase in distance walked in the walking test was noted, which changed significantly after training, 377±59.7 to 415±79 m after one year (P<.01). A statistically significant improvement in mean scores of HRQoL was observed, except for the emotional role dimension of the SF-36 questionnaire.

CONCLUSION

A pulmonary rehabilitation programme for 8 weeks improved the exercise capacity, dyspnoea and quality of life of patients with severe and very severe chronic obstructive pulmonary disease.

A Lifestyle Physical Activity Intervention for Patients with Chronic Obstructive Pulmonary Disease. A Randomized Controlled Trial

RATIONALE

Physical inactivity is associated with poor outcomes among patients with chronic obstructive pulmonary disease (COPD).

OBJECTIVES

To determine effectiveness of a behavioral intervention intended to increase daily physical activity with the goal of improving health-related quality of life and functional performance.

METHODS

We conducted a randomized trial among patients with COPD cared for in primary care and pulmonary clinics. The patients were at least 45 years of age and eligible for pulmonary rehabilitation. All patients received self-management education during a 6-week run-in period. Subsequently, patients were randomized to usual care or the intervention delivered over 20 weeks.

MEASUREMENTS AND MAIN RESULTS

Co-primary outcomes were change from baseline in Chronic Respiratory Questionnaire dyspnea domain score and 6-minute-walk distance measured at 6, 12, and 18 months after randomization. A total of 325 patients were enrolled, with 156 randomized to receive usual care and 149 to receive the intervention. At 18 months, there was no overall statistical or clinically significant change in the dyspnea domain in either group. However, for 6-minute-walk distance, there were statistically significant declines in both groups. In contrast, 6-minute-walk distance remained stable (5.3 m; P = 0.54) among patients in the intervention group with moderate spirometric impairment, but it was associated with clinically and statistically significant declines (-28.7 m; P = 0.0001) among usual care patients with moderate spirometric impairment. Overall, there was no increase in adverse events associated with the intervention, which was associated with a lower prevalence of hospitalization for COPD exacerbations (28.3%) compared with usual care (49.5%).

CONCLUSIONS

During this 18-month trial among outpatients with COPD, a health coach-based behavioral intervention did not improve scores in the dyspnea domain of the Chronic Respiratory Questionnaire or 6-minute-walk test distance. However, subgroup analyses suggested that there may be differential effects for specific outcomes that vary with severity of COPD. Specifically, benefits of this low-intensity intervention may be limited to 6-minute walk distance among patients with moderate spirometric impairment. Clinical trial registered with www.clinicaltrials.gov (NCT1108991).

Minimal important difference and responsiveness of 2-minute walk test performance in people with COPD undergoing pulmonary rehabilitation

BACKGROUND AND OBJECTIVES

Field exercise tests (eg, 6-minute walk test [6MWT]) are important measures of functional exercise capacity in people with COPD. Shorter tests such as the 2-minute walk test (2MWT) may offer advantages in some populations but lack information about responsiveness to change. This study examined responsiveness, minimal important difference (MID), test-retest reliability, and construct validity of the 2MWT in people with stable COPD attending outpatient pulmonary rehabilitation (PR).

METHODS

At pre-PR assessment, study participants completed a 2MWT twice in addition to usual measures (6MWT and Chronic Respiratory Questionnaire). At post-PR assessment following a standard PR program, measures were repeated and global rating of change scores obtained (patient and therapist). Pre-post program change scores were examined for correlations with change in 2-minute walk distance (2MWD) and used (where r≥0.3) to estimate the MID through anchor-based methods. Distribution-based estimates based on standard error of measurement were examined. Test-retest reliability (intraclass correlation coefficient [ICC] and Bland-Altman agreement) and validity (Pearson correlation with 6-minute walk distance [6MWD]) were reported.

RESULTS

Fifty-nine people (28 men) with stable COPD, mean age 68 years (SD 10 years), and percentage predicted forced expiratory volume in 1 second 48% (SD 20%) attended pre-PR assessment. Test-retest ICC for same-session 2MWD was 0.985. A mean difference of 2.4 m (95% confidence interval [CI] 0.7-4.0 m, P=0.006) occurred between the first and second trials. 2MWD and 6MWD were highly correlated (r=0.87, P<0.001). Forty-one participants completed PR and were included in responsiveness and MID analysis. Mean 2MWD improved significantly post-PR (8.8 m, 95% CI 3.6-14 m, P=0.001). The MID in 2MWD, anchored against clinically meaningful change in 6MWD, was 5.5 m (area under curve =0.81, P=0.001). Distribution-based methods estimated an MID of 4 m.

CONCLUSION

Change in 2MWD of at least 5.5 m following a PR program corresponded to a clinically meaningful change. A practice test is recommended due to learning effects.

Effect of a rehabilitation-based chronic disease management program targeting severe COPD exacerbations on readmission patterns

Background

Pulmonary rehabilitation (PR) is recommended after a severe COPD exacerbation, but its short- and long-term effects on health care utilization have not been fully established.

Aims

The aims of this study were to evaluate patient compliance with a chronic disease management (CDM) program incorporating home-based exercise training as the main component after a severe COPD exacerbation and to determine its effects on health care utilization in the following year.

Materials and methods

COPD patients with a severe exacerbation were included in a case-cohort study at admission. An intervention group participated in a nurse-supervised CDM program during the 2 months after discharge, comprising of home-based PR with exercise components directly supervised by a physiotherapist, while the remaining patients followed usual care.

Results

Nineteen of the twenty-one participants (90.5%) were compliant with the CDM program and were compared with 29 usual-care patients. Compliance with the program was associated with statistically significant reductions in admissions due to respiratory disease in the following year (median [interquartile range]: 0 [0–1] vs 1 [0–2.5]; P=0.022) and in days of admission (0 [0–7] vs 7 [0–12]; P=0.034), and multiple linear regression analysis confirmed the protective effect of the CDM program (β coefficient −0.785, P=0.014, and R²=0.219).

Conclusion

A CDM program incorporating exercise training for COPD patients without limiting comorbidities after a severe exacerbation achieves high compliance and reduces admissions in the year following after the intervention.

An evaluation of activity tolerance, patient-reported outcomes and satisfaction with the effectiveness of pulmonary daoyin on patients with chronic obstructive pulmonary disease

BACKGROUND AND OBJECTIVE

Pulmonary Daoyin (PD) (evolved from ancient Chinese daoyin skills), is a rehabilitation technology that combines specially designed movements of the arms and body and controlled breathing exercises, to improve the physiological and psychological status of patients with chronic respiratory disease. Pulmonary rehabilitation is effective for patients with chronic obstructive pulmonary disease (COPD), and the efficacy of PD is unknown. The aim of this study is to investigate the effect of a PD program in enhancing activity tolerance, patient-reported outcomes and satisfaction with the effectiveness on patients with COPD.

MATERIALS AND METHODS

The multi-center, randomized controlled trial was conducted from November 2011 to June 2012 in local communities in cities of the 11 research centers in China. It included COPD patients (moderate to very severe) who were recruited from an outpatient clinic. A randomized controlled study included 464 COPD patients who were randomly allocated either to the PD group, participating in a 3-month, ten times-weekly supervised PD-based pulmonary rehabilitation program, or to a control group continuing with regular medical treatment alone. Data were gathered using the 6-minute walking distance (6MWD) test, COPD patient-reported outcomes (COPD-PRO) and Effectiveness Satisfaction Questionnaire for COPD (ESQ-COPD), which was filled out at baseline and 3 months post-intervention. SAS 9.2 was used for statistical analysis.

RESULTS

Of the 464 patients in the study, 461 were included in the full analysis set (FAS); 429 were in the per-protocol analysis set (PPS). After 3-month intervention, there was a significant difference between the two groups in 6MWD (FAS; P=0.049; PPS; P=0.041), total score and all domains of COPD-PRO (FAS; P=0.014; PPS; P=0.003) and ESQ-COPD (FAS; P=0.038; PPS; P<0.001).

CONCLUSIONS

The PD program was able to improve the activity tolerance level and satisfaction of COPD patients because of its effectiveness.

Relationships between heart rate target determined in different exercise testing in COPD patients to prescribed with individualized exercise training

Background

It has been scientifically proven that pulmonary rehabilitation improves exercise tolerance and facilitates the carrying out of daily physical activities. To optimize the physical and physiological benefits, it is necessary to individualize the training intensity for each patient. The aim of this study is to compare the heart rate (HR) responses to three exercise modalities measuring aerobic fitness in chronic obstructive pulmonary disease patients, in order to easily prescribe individual target HRs for endurance training.

Patients and method

Fifty COPD patients (mean age: 60.1±8.5 years) were included in the study. Each patient carried out a cardiopulmonary exercise test, a 6-minute walk test (6MWT) and a 6-minute stepper test (6MST). During these tests, HR was recorded continuously. After the cardiopulmonary exercise test, the HR was noted at the ventilatory threshold (VT) and at the end of the two exercise field tests (6MWT_peak and 6MST_peak). The values of the HR during the last 3 minutes of both field tests were averaged (6MWT₄₅₆ and 6MST₄₅₆). Finally, the HR at 60% of the HR reserve was calculated with the values of the HR measured during 6MWT and 6MST (HRr_60%walk, HRr_60%step).

Results

The HRs measured during the 6MST were significantly higher than those measured during the 6MWT. The HRr_60%step was not significantly different from 6MWT₄₅₆ and 6MWT_peak HR (P=0.51; P=0.48). A significant correlation was observed between 6MWT₄₅₆ and 6MWT_peak (r=0.58). The 6MWT₄₅₆ and 6MWT_peak HR were correlated with HRr_60%step (r=0.68 and r=0.62). The VT could be determined in 28 patients. The HR_VT was not different from 6MWT₄₅₆, 6MWT_peak, and HRr_60%step (P=0.57, P=0.41 and P=0.88) and was correlated to 6MWT₄₅₆, 6MWT_peak, and HRr_60%step (r=0.45, r=0.40, r=0.48).

Conclusion

An individualized target HR for endurance training can be prescribed from the HR measured during routine tests, such as 6MWT or 6MST.

Short-term and long-term effects of a self-managed physical activity program using a pedometer for chronic respiratory disease: a randomized controlled trial

[Purpose] The aim of this study was to evaluate the effects of a self-managed physical activity program using a pedometer and diary on physical function, ADL, and QOL in patients with chronic respiratory disease. [Subjects and Methods] 17 outpatients with chronic respiratory disease were assessed for dyspnea, muscle strength, exercise tolerance, ADL, and QOL at baseline, after 3-, and 6-months after the start of the program. Patients were randomly assigned to "Control" or "Diary" group. In the Diary group, the number of steps was counted with a pedometer and recorded in a diary together with self-evaluation of physical activity, while patients assigned to the Control group did not use a pedometer or keep a diary. [Results] The Diary group showed significant improvement in the daily step count over time. The Diary group showed significant improvement of the dyspnea, muscle strength, and exercise tolerance at 3 months, dyspnea and muscle strength at 6 months. Significant differences found between two groups with regard to the extent of change in the muscle strength, exercise tolerance, and QOL at 3 months. [Conclusion] This study suggests that a self-managed physical activity program using a pedometer and diary can increase the level of physical activity.

Minimal clinically important difference for the 6-min walk test: literature review and application to Morquio A syndrome

Morquio A syndrome is an ultra-rare, inherited lysosomal storage disorder associated with progressive, multi-systemic clinical impairments, causing gradual loss of functional capacity and endurance, impaired quality of life, and early mortality. Studies in Morquio A patients have used the 6-min walk test (6MWT) to assess functionality and endurance and to evaluate disease progression or efficacy of treatment. The objective of the present study was to review minimal clinically important differences (MCIDs) for the 6MWT reported for disease states that widely use the 6MWT to evaluate clinical benefit and to discuss the results in view of the challenges in estimating MCID for ultra-rare diseases, using the case of elosulfase alfa in Morquio A patients. A systematic literature search was performed using Embase and Medline to identify studies specifically estimating the MCID using either anchor-based or distribution-based methods. A total of 19 publications on 17 studies were identified; none of these included patients with Morquio A syndrome or the wider disease category of lysosomal storage disorders. Therefore, the MCIDs determined by studies in patients with respiratory, cardiovascular, or musculoskeletal disease were compared to changes in the 6MWT seen in Morquio A patients in the pivotal phase 3 clinical trial of elosulfase alfa enzyme replacement therapy. The literature review showed a mean MCID for the 6MWT of 7% change (range 3–15%) in studies using anchor-based methods and a 9% change (range 4–16%) using distribution-based methods. Results of the elosulfase alfa clinical trial and its extension showed a placebo-adjusted 14.9% improvement in the 6MWT from baseline at week 24, which was greater than the mean MCID based on the results of the systematic literature review. After 2 years, 6MWT distance increased by a mean of 20.7% from baseline in a modified per-protocol population, versus a reduction of 6.9% in comparable untreated patients from the MorCAP natural history study over the same period. Although further research is required to establish the MCID of the 6MWT in Morquio A patients, the presented data provide further evidence for the positive effect of elosulfase alfa in this patient population.

The Differential Impact of Emphysema on Respiratory Symptoms and 6-Minute Walk Distance in HIV Infection

BACKGROUND

Emphysema is more prevalent in HIV-infected (HIV+) patients independent of smoking behavior. Nonetheless, health effects of emphysema in this population are poorly understood. We determined whether emphysema is associated with a greater burden of pulmonary symptoms and a lower 6-minute walk distance (6MWD) in HIV+ compared with HIV-uninfected (HIV-) subjects.

METHODS

We performed a cross-sectional analysis of 170 HIV+ and 153 HIV- subjects in the Examinations of HIV-Associated Lung Emphysema (EXHALE) cohort study. Subjects completed a self-assessment of respiratory symptoms, pulmonary function testing, and 6MWD testing as well as a chest computed tomography to determine emphysema severity. We used regression models to determine the association of emphysema with respiratory symptoms and 6MWD in HIV+ subjects and compared this to HIV- subjects.

RESULTS

Models stratified by HIV status demonstrated an association between >10% radiographic emphysema and chronic cough and/or phlegm and 6MWD in HIV+ subjects. These associations persisted among the subset without airflow obstruction: those with emphysema had 4.2 (95% confidence interval: 1.3 to 14) times the odds of chronic cough and/or phlegm and walked 60 m (95% confidence interval: 26 to 93) less distance than those without emphysema. There was no association between >10% emphysema and symptoms or 6MWD in HIV- subjects.

CONCLUSIONS

In our cohort, >10% radiographic emphysema was associated with chronic cough and/or phlegm and lower 6MWD in HIV+ but not HIV- subjects. These findings were robust even among HIV+ subjects with milder forms of emphysema and those without airflow obstruction, highlighting the clinical impact of emphysema in these patients.

Comparison of the Dyspnoea-12 and Multidimensional Dyspnoea Profile in people with COPD

We directly compared convergent, discriminant and concurrent validity of the Dyspnoea-12 (D-12) and Multidimensional Dyspnoea Profile (MDP) in people with chronic obstructive pulmonary disease.

Breathlessness measures (D-12, MDP, visual analogue scales and descriptors) were completed for two focal periods (daily life and end of walk test). Instrument structure (D-12 and MDP item grouping) was assessed with factor analysis. Differences between airflow severity stage and focal periods (ANOVA, t-test and Chi-squared test), associations between D-12 and MDP (r, r2 for static pulmonary function, 6-min walk test and self-reported measures of impairment) and individual consistency for comparable items of the D-12 and MDP (McNemar's test) were assessed.

In 84 participants (mean±sd age 70±9 years, 47 males, forced expiratory volume in 1 s 48±17% predicted), item groupings were confirmed for both focal periods. Developer-recommended single and subdomain scores were highly correlated, and demonstrated similar convergent, discriminant and concurrent validity. Individual consistency differed between the D-12 and MDP according to item/item groups.

At the level of developer-recommended single and subdomain scores, the D-12 and MDP share similar psychometric properties, but these instruments serve different purposes, do not assess the same sensations or emotions and are not interchangeable.

The 6-Minute-Walk Distance Test as a Chronic Obstructive Pulmonary Disease Stratification Tool. Insights from the COPD Biomarker Qualification Consortium

RATIONALE

The 6-minute-walk distance (6MWD) test predicts mortality in chronic obstructive pulmonary disease (COPD). Whether variability in study type (observational vs. interventional) or region performed limits use of the test as a stratification tool or outcome measure for therapeutic trials is unclear.

OBJECTIVES

To analyze the original data from several large observational studies and from randomized clinical trials with bronchodilators to support the qualification of the 6MWD test as a drug development tool in COPD.

METHODS

Original data from 14,497 patients with COPD from six observational (n = 9,641) and five interventional (n = 4,856) studies larger than 100 patients and longer than 6 months in duration were included. The geographical, anthropometrics, FEV1, dyspnea, comorbidities, and health status scores were measured. Associations between 6MWD and mortality, hospitalizations, and exacerbations adjusted by study type, age, and sex were evaluated. Thresholds for outcome prediction were calculated using receiver operating curves. The change in 6MWD after inhaled bronchodilator treatment and surgical lung volume reduction were analyzed to evaluate the responsiveness of the test as an outcome measure.

MEASUREMENTS AND MAIN RESULTS

The 6MWD was significantly lower in nonsurvivors, those hospitalized, or who exacerbated compared with those without events at 6, 12, and greater than 12 months. At these time points, the 6MWD receiver operating characteristic curve-area under the curve to predict mortality was 0.71, 0.70, and 0.68 and for hospitalizations was 0.61, 0.60, and 0.59, respectively. After treatment, the 6MWD was not different between placebo and bronchodilators but increased after surgical lung volume reduction compared with medical therapy. Variation across study types (observational or therapeutic) or regions did not confound the ability of 6MWD to predict outcome.

CONCLUSIONS

The 6MWD test can be used to stratify patients with COPD for clinical trials and interventions aimed at modifying exacerbations, hospitalizations, or death.

Comparing Various Exercise Tests for Assessing the Response to Pulmonary Rehabilitation in Patients With COPD

PURPOSE

Various exercise tests have been used to assess the response to pulmonary rehabilitation (PR) in patients with chronic obstructive pulmonary disease (COPD). Few studies have compared exercise tests in the same subjects to determine the relative responsiveness of various tests. The goal of this pilot study was to examine the responsiveness of different exercise tests in patients with COPD completing PR.

METHODS

Fifteen male patients with COPD underwent PR. All subjects completed 6-minute walk test (6MWT), incremental shuttle walk test (ISWT), endurance shuttle walk test (ESWT), maximal incremental exercise test (MIET), constant workload exercise test (CWET), and maximal arm ergometry tests before and after PR. The Chronic Respiratory Disease Questionnaire was also completed before and after PR.

RESULTS

The number of participants who exceeded the minimal clinically important difference was similar for each of the different exercise tests. Effect sizes for the MIET and CWET were slightly higher, 0.82 and 0.97, respectively, than for the 6MWT, ISWT, and ESWT, 0.72, 0.65, and 0.60, respectively. Effect sizes were not significantly different between the 6MWT and the ESWT. The changes in exercise test results were not significantly correlated with the changes in quality of life. The improvement in laboratory cycling tests did not significantly correlate with the improvement in shuttle walk tests.

CONCLUSIONS

On the basis of these data, all exercise measures were responsive to PR. Indices derived from cycling in the laboratory appeared more responsive than indices derived from walking in the field when assessed by effect size, but this finding and its possible clinical significance requires confirmation in a larger study.

Pulmonary rehabilitation following exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Guidelines have provided positive recommendations for pulmonary rehabilitation after exacerbations of chronic obstructive pulmonary disease (COPD), but recent studies indicate that postexacerbation rehabilitation may not always be effective in patients with unstable COPD.

OBJECTIVES

To assess effects of pulmonary rehabilitation after COPD exacerbations on hospital admissions (primary outcome) and other patient-important outcomes (mortality, health-related quality of life (HRQL) and exercise capacity).

SEARCH METHODS

We identified studies through searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PEDro (Physiotherapy Evidence Database) and the Cochrane Airways Review Group Register of Trials. Searches were current as of 20 October 2015, and handsearches were run up to 5 April 2016.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing pulmonary rehabilitation of any duration after exacerbation of COPD versus conventional care. Pulmonary rehabilitation programmes had to include at least physical exercise (endurance or strength exercise, or both). We did not apply a criterion for the minimum number of exercise sessions a rehabilitation programme had to offer to be included in the review. Control groups received conventional community care without rehabilitation.

DATA COLLECTION AND ANALYSIS

We expected substantial heterogeneity across trials in terms of how extensive rehabilitation programmes were (i.e. in terms of number of completed exercise sessions; type, intensity and supervision of exercise training; and patient education), duration of follow-up (< 3 months vs ≥ 3 months) and risk of bias (generation of random sequence, concealment of random allocation and blinding); therefore, we performed subgroup analyses that were defined before we carried them out. We used standard methods expected by Cochrane in preparing this update, and we used GRADE for assessing the quality of evidence.

MAIN RESULTS

For this update, we added 11 studies and included a total of 20 studies (1477 participants). Rehabilitation programmes showed great diversity in terms of exercise training (number of completed exercise sessions; type, intensity and supervision), patient education (from none to extensive self-management programmes) and how they were organised (within one setting, e.g. pulmonary rehabilitation, to across several settings, e.g. hospital, outpatient centre and home). In eight studies, participants completed extensive pulmonary rehabilitation, and in 12 studies, participants completed pulmonary rehabilitation ranging from not extensive to moderately extensive.Eight studies involving 810 participants contributed data on hospital readmissions. Moderate-quality evidence indicates that pulmonary rehabilitation reduced hospital readmissions (pooled odds ratio (OR) 0.44, 95% confidence interval (CI) 0.21 to 0.91), but results were heterogenous (I² = 77%). Extensiveness of rehabilitation programmes and risk of bias may offer an explanation for the heterogeneity, but subgroup analyses were not statistically significant (P values for subgroup effects were between 0.07 and 0.11). Six studies including 670 participants contributed data on mortality. The quality of evidence was low, and the meta-analysis did not show a statistically significant effect of rehabilitation on mortality (pooled OR 0.68, 95% CI 0.28 to 1.67). Again, results were heterogenous (I² = 59%). Subgroup analyses showed statistically significant differences in subgroup effects between trials with more and less extensive rehabilitation programmes and between trials at low and high risk for bias, indicating possible explanations for the heterogeneity. Hospital readmissions and mortality studies newly included in this update showed, on average, significantly smaller effects of rehabilitation than were seen in earlier studies.High-quality evidence suggests that pulmonary rehabilitation after an exacerbation improves health-related quality of life. The eight studies that used St George's Respiratory Questionnaire (SGRQ) reported a statistically significant effect on SGRQ total score, which was above the minimal important difference (MID) of four points (mean difference (MD) -7.80, 95% CI -12.12 to -3.47; I² = 64%). Investigators also noted statistically significant and important effects (greater than MID) for the impact and activities domains of the SGRQ. Effects were not statistically significant for the SGRQ symptoms domain. Again, all of these analyses showed heterogeneity, but most studies showed positive effects of pulmonary rehabilitation, some studies showed large effects and others smaller but statistically significant effects. Trials at high risk of bias because of lack of concealment of random allocation showed statistically significantly larger effects on the SGRQ than trials at low risk of bias. High-quality evidence shows that six-minute walk distance (6MWD) improved, on average, by 62 meters (95% CI 38 to 86; I² = 87%). Heterogeneity was driven particularly by differences between studies showing very large effects and studies showing smaller but statistically significant effects. For both health-related quality of life and exercise capacity, studies newly included in this update showed, on average, smaller effects of rehabilitation than were seen in earlier studies, but the overall results of this review have not changed to an important extent compared with results reported in the earlier version of this review.Five studies involving 278 participants explicitly recorded adverse events, four studies reported no adverse events during rehabilitation programmes and one study reported one serious event.

AUTHORS' CONCLUSIONS

Overall, evidence of high quality shows moderate to large effects of rehabilitation on health-related quality of life and exercise capacity in patients with COPD after an exacerbation. Some recent studies showed no benefit of rehabilitation on hospital readmissions and mortality and introduced heterogeneity as compared with the last update of this review. Such heterogeneity of effects on hospital readmissions and mortality may be explained to some extent by the extensiveness of rehabilitation programmes and by the methodological quality of the included studies. Future researchers must investigate how the extent of rehabilitation programmes in terms of exercise sessions, self-management education and other components affects the outcomes, and how the organisation of such programmes within specific healthcare systems determines their effects after COPD exacerbations on hospital readmissions and mortality.

Minimal important improvement thresholds for the six-minute walk test in a knee arthroplasty cohort: triangulation of anchor- and distribution-based methods

Background

The 6-minute walk test (6MWT) is a commonly used metric for measuring change in mobility after knee arthroplasty, however, what is considered an improvement after surgery has not been defined. The determination of important change in an outcome assessment tool is controversial and may require more than one approach. This study, nested within a combined randomised and observational trial, aimed to define a minimal important improvement threshold for the 6MWT in a knee arthroplasty cohort through a triangulation of methods including patient-perceived anchor-based thresholds and distribution-based thresholds.

Methods

Individuals with osteoarthritis performed a 6MWT pre-arthroplasty then at 10 and 26 weeks post-surgery. Each rated their perceived improvement in mobility post-surgery on a 7-point transition scale anchored from “much better” to “much worse”. Based on these responses the cohort was dichotomised into ‘improved’ and ‘not improved’. The thresholds for patient-perceived improvements were then identified using two receiver operating curve methods producing sensitivity and specificity indices. Distribution-based change thresholds were determined using two methods utilising effect size (ES). Agreement between the anchor- and distribution-based methods was assessed using kappa.

Results

One hundred fifty-eight from 166 participants in the randomised cohort and 222 from 243 in the combined randomised and observational cohort were included at 10 and 26 weeks, respectively. The slightly or more patient-perceived improvement threshold at 26 weeks (an absolute improvement of 26 m) was the only one to demonstrate sensitivity and specificity results both better than chance. At 10- and 26-weeks, the ES based on the mean change score divided by the baseline standard deviation (SD), was an absolute change of 24.5 and 37.9 m, respectively. The threshold based on a moderate ES (a 0.5 SD of the baseline score) was a change of 55.0 and 55.4 m at 10- and 26-weeks, respectively. The level of agreement between the 26-week anchor-based and distribution-based minimal absolute changes was very good (k = 0.88 (95 % CI 0.81 0.95)).

Conclusion

A valid threshold of improvement for the 6MWT can only be proposed for changes identified from baseline to 26 weeks post-surgery. The level of agreement between anchor- and distribution-based methods indicates that a true minimal or more threshold of meaningful improvement following surgery is likely within the ranges proposed by the triangulation of all four methods, that is, 26 to 55 m.

A randomized controlled trial of telephone-mentoring with home-based walking preceding rehabilitation in COPD

PURPOSE

With the limited reach of pulmonary rehabilitation (PR) and low levels of daily physical activity in chronic obstructive pulmonary disease (COPD), a need exists to increase daily exercise. This study evaluated telephone health-mentoring targeting home-based walking (tele-rehab) compared to usual waiting time (usual care) followed by group PR.

PATIENTS AND METHODS

People with COPD were randomized to tele-rehab (intervention) or usual care (controls). Tele-rehab delivered by trained nurse health-mentors supported participants' home-based walking over 8-12 weeks. PR, delivered to both groups simultaneously, included 8 weeks of once-weekly education and self-management skills, with separate supervised exercise. Data were collected at three time-points: baseline (TP1), before (TP2), and after (TP3) PR. The primary outcome was change in physical capacity measured by 6-minute walk distance (6MWD) with two tests performed at each time-point. Secondary outcomes included changes in self-reported home-based walking, health-related quality of life, and health behaviors.

RESULTS

Of 65 recruits, 25 withdrew before completing PR. Forty attended a median of 6 (4) education sessions. Seventeen attended supervised exercise (5±2 sessions). Between TP1 and TP2, there was a statistically significant increase in the median 6MWD of 12 (39.1) m in controls, but no change in the tele-rehab group. There were no significant changes in 6MWD between other time-points or groups, or significant change in any secondary outcomes. Participants attending supervised exercise showed a nonsignificant improvement in 6MWD, 12.3 (71) m, while others showed no change, 0 (33) m. The mean 6MWD was significantly greater, but not clinically meaningful, for the second test compared to the first at all time-points.

CONCLUSION

Telephone-mentoring for home-based walking demonstrated no benefit to exercise capacity. Two 6-minute walking tests at each time-point may not be necessary. Supervised exercise seems essential in PR. The challenge of incorporating exercise into daily life in COPD is substantial.

Medium term effects of including manual therapy in a pulmonary rehabilitation program for chronic obstructive pulmonary disease (COPD): a randomized controlled pilot trial

STUDY DESIGN

Randomized clinical trial.

OBJECTIVE

To investigate the effect of including manual therapy (MT) in a pulmonary rehabilitation program for patients with chronic obstructive pulmonary disease (COPD).

BACKGROUND

The primary source of exercise limitation in people with COPD is dyspnea. The dyspnea is partly caused by changes in chest wall mechanics, with an increase in chest wall rigidity (CWR) contributing to a decrease in lung function. As MT is known to increase joint mobility, administering MT to people with COPD carries with it the potential to influence CWR and lung function.

METHODS

Thirty-three participants with COPD, aged between 55 and 70 years (mean = 65·5±4 years), were randomly assigned to three groups: pulmonary rehabilitation (PR) only, soft tissue therapy (ST) and PR, and ST, spinal manipulative therapy (SM), and PR. Outcome measures including forced expiratory volume in the 1st second (FEV1), forced vital capacity (FVC), 6-minute walking test (6MWT), St. George's respiratory questionnaire (SGRQ), and the hospital anxiety and depression (HAD) scale were recorded at 0, 8, 16, and 24 weeks.

RESULTS

There was a significant difference in FVC between the three groups at 24 weeks (P = 0·04). For the ST+SM+PR group versus PR only the increase was 0·40 l (CI: 0·02, 0·79; P = 0·03). No major or moderate adverse events (AE) were reported following the administration of 131 ST and 272 SM interventions.

DISCUSSION

The increase in FVC is a unique finding. Although the underlying mechanisms responsible for this outcome are not yet understood, the most likely explanation is the synergistic effect resulting from the combination of interventions. These results support the call for a larger clinical trial in the use of MT for COPD.

Impact of pulmonary rehabilitation on hospitalizations for chronic obstructive pulmonary disease among members of an integrated health care system

PURPOSE

The evidence regarding the effects of pulmonary rehabilitation (PR) on health care resource use remains limited. This retrospective study evaluated the effects of PR on the primary outcome of all-cause hospitalizations and secondary outcomes of other health care use, exercise capacity, health-related quality of life (HRQOL), and body weight in patients with chronic obstructive pulmonary disease (COPD) in a large integrated health care system.

METHODS

The PR cohort included 558 patients with a COPD diagnosis, age ≥ 40 years, who were treated with a bronchodilator or steroid inhaler, participated in 1 of 13 PR programs between January 1, 2008, and August 1, 2013, and were continuously enrolled in the health plan ≥ 12 months prior to and after PR. Two non-PR control cohorts were assembled for comparison. Data were extracted from electronic health records. The 6-minute walk test and St. George's Respiratory Questionnaire results were available for a subset.

RESULTS

The proportion of patients who were hospitalized 12 months post-PR was lower compared with the 12 months prior (37% vs 45%, P = .001) while emergency department use was not different (52% vs 54%). Patients who declined PR for logistical reasons had a 40% higher risk of hospitalization than PR participants (relative risk = 1.40, 95% CI: 0.96-2.06, P = .08). There were significant improvements in the 6-minute walk test distance (+43 m) and the St. George's Respiratory Questionnaire total score (-9.6 points) but minimal changes in weight.

CONCLUSIONS

Our finding that participation in PR is associated with reductions in hospitalizations corroborates previous studies. A notable strength of this study is the capture of complete utilization data.

Six-minute walk test is reliable and valid in spinal muscular atrophy

INTRODUCTION

The Six-Minute Walk Test (6MWT) was adopted as a clinical outcome measure for ambulatory spinal muscular atrophy (SMA). However, a systematic review of measurement properties reported significant variation among chronic pediatric conditions. Our purpose was to assess the reliability/validity of the 6MWT in SMA.

METHODS

Thirty participants performed assessments, including the 6MWT, strength, and function. Reproducibility was evaluated by intraclass correlation coefficients. Criterion/convergent validity were determined using Pearson correlation coefficients.

RESULTS

Test-retest reliability was excellent. The 6MWT was associated positively with peak oxygen uptake, Hammersmith Functional Motor Scale Expanded (HFMSE), lower extremity manual muscle testing, knee flexion hand-held dynamometry, and inversely with 10-m walk/run. The 6MWT discriminates between disease severity, unlike the HFMSE.

CONCLUSIONS

This study documents measurement properties of reproducibility, positive criterion validity, and convergent validity with established clinical assessments and reaffirms the value of the 6MWT as a pivotal outcome measure in SMA clinical trials. Muscle Nerve 54: 836-842, 2016.

Six-minute stepper test: a valid clinical exercise tolerance test for COPD patients

Introduction

Exercise tolerance testing is an integral part of the pulmonary rehabilitation (PR) management of patients with chronic obstructive pulmonary disease (COPD). The 6-minute stepper test (6MST) is a new, well-tolerated, reproducible exercise test, which can be performed without any spatial constraints.

Objective

The aim of this study was to compare the results of the 6MST to those obtained during a 6-minute walk test (6MWT) and cardiopulmonary exercise testing (CPET) in a cohort of COPD patients.

Methods

Ninety-one COPD patients managed by outpatient PR and assessed by 6MST, 6MWT, and CPET were retrospectively included in this study. Correlations between the number of steps on the 6MST, the distance covered on the 6MWT, oxygen consumption, and power at the ventilatory threshold and at maximum effort during CPET were analyzed before starting PR, and the improvement on the 6MST and 6MWT was compared after PR.

Results

The number of steps on the 6MST was significantly correlated with the distance covered on the 6MWT (r=0.56; P<0.0001), the power at maximum effort (r=0.46; P<0.0001), and oxygen consumption at maximum effort (r=0.39; P<0.005). Performances on the 6MST and 6MWT were significantly improved after PR (570 vs 488 steps, P=0.001 and 448 vs 406 m, respectively; P<0.0001). Improvements of the 6MST and 6MWT after PR were significantly correlated (r=0.34; P=0.03).

Conclusion

The results of this study show that the 6MST is a valid test to evaluate exercise tolerance in COPD patients. The use of this test in clinical practice appears to be particularly relevant for the assessment of patients managed by home PR.

Effectiveness of Repeated Courses of Pulmonary Rehabilitation on Functional Exercise Capacity in Patients With COPD

PURPOSE

To determine whether an as-needed repeated pulmonary rehabilitation (PR) intervention produces a clinically important improvement in exercise capacity.

METHODS

The study included a retrospective analysis of characteristics and 6-minute walk distance (6MWD) of patients with chronic obstructive pulmonary disease (COPD) who completed PR at 2 centers. Data were abstracted from all patients with COPD completing 2 courses of rehabilitation and those of randomly sampled patients completing only 1 course of PR.

RESULTS

We identified 37 repeaters and selected 69 nonrepeaters for analysis. No significant differences between the 2 groups with regard to age, FEV1 percent predicted, gender, initial 6MWD, improvement in 6MWD, and the percentage of patients achieving the minimal important difference (MID) of ≥ 35 m were observed with the completion of the first rehabilitation. The time between the first and second PR interventions was a mean of 45 ± 24 months. Repeating patients had a decrease of 90 ± 76 m in 6MWD at the beginning of the second rehabilitation course compared with the end of the first intervention (P = .001). Twenty-four (65%) of repeating patients achieved the MID in 6MWD at the end of the second course of PR. Those who achieved the MID in 6MWD during the second course of rehabilitation also tended to have attained greater improvement in this outcome during the first course (P = .07).

CONCLUSION

Two-thirds of patients with COPD undergoing repeat PR experienced significant improvement in exercise capacity. Offering PR to patients with COPD on an as-needed basis appears to be beneficial even after a prolonged period of time between the interventions.

Comparison of two- and six-minute walk tests in detecting oxygen desaturation in patients with severe chronic obstructive pulmonary disease - A randomized crossover trial

The two-minute walk test (2MWT) is less well validated than the well-known six-minute walk test (6MWT) as a field walking test in patients with chronic obstructive pulmonary disease (COPD). The primary objective of this study was to compare the accuracy of the 2MWT to the 6MWT in detecting exercise-induced oxygen desaturation in patients with severe COPD. Twenty-six patients with COPD (age: 61 ± 10 years, forced expired volume in one second: 37 ± 10%) that were normoxemic at rest performed a 2MWT and a 6MWT under normal ambient conditions on two consecutive days in random order. Oxygen saturation, total walking distance, heart rate, breathing frequency, dyspnea, and leg fatigue were evaluated. Average walking distances were 150 m (95% confidence interval (95% CI): 134-165 m) and 397 m (95% CI: 347-447 m) for the 2MWT and 6MWT, respectively (r = 0.80, p < 0.0001). The difference in minimum oxygen saturation during the 2MWT (83%, 95% CI: 81-86%) and 6MWT (mean 82%, 95% CI: 80-84%) was not statistically different and the data strongly correlated between the groups (r = 0.81, p < 0.0001). Other measurements from the 6MWT, including heart rate, breathing rate, and levels of perceived exertion were also comparable in 2MWT. The 2MWT showed comparable validity in detecting exercise-induced oxygen desaturation in patients with severe COPD compared to the 6MWT.

Physical Activity Counselling during Pulmonary Rehabilitation in Patients with COPD: A Randomised Controlled Trial

Background

Pulmonary rehabilitation programs only modestly enhance daily physical activity levels in patients with chronic obstructive pulmonary disease (COPD). This randomised controlled trial investigates the additional effect of an individual activity counselling program during pulmonary rehabilitation on physical activity levels in patients with moderate to very severe COPD.

Methods

Eighty patients (66±7 years, 81% male, forced expiratory volume in 1 second 45±16% of predicted) referred for a six‐month multidisciplinary pulmonary rehabilitation program were randomised. The intervention group was offered an additional eight-session activity counselling program. The primary outcomes were daily walking time and time spent in at least moderate intense activities.

Results

Baseline daily walking time was similar in the intervention and control group (median 33 [interquartile range 16–47] vs 29 [17–44]) whereas daily time spent in at least moderate intensity was somewhat higher in the intervention group (17[4–50] vs 12[2–26] min). No significant intervention*time interaction effects were observed in daily physical activity levels. In the whole group, daily walking time and time spent in at least moderate intense activities did not significantly change over time.

Conclusions

The present study identified no additional effect of eight individual activity counselling sessions during pulmonary rehabilitation to enhance physical activity levels in patients with COPD.

Trial Registration

clinicaltrials.gov NCT00948623

Long-term Exercise After Pulmonary Rehabilitation (LEAP): Design and rationale of a randomized controlled trial of Tai Chi

BACKGROUND

Persons with chronic obstructive pulmonary disease (COPD) have reduced exercise capacity and levels of physical activity. Supervised, facility-based pulmonary rehabilitation programs improve exercise capacity and reduce dyspnea, but novel long-term strategies are needed to maintain the benefits gained. Mind-body modalities such as Tai Chi which combine aerobic activity, coordination of breathing, and cognitive techniques that alleviate the physical inactivity, dyspnea, and anxiety and depression that are the hallmarks of COPD are promising strategies.

METHODS/DESIGN

We have designed a randomized controlled study to examine whether Tai Chi will maintain exercise capacity in persons with COPD who have recently completed a supervised pulmonary rehabilitation program, compared to standard care. The primary outcome is 6-min walk test distance at 6 months. Secondary outcomes include health-related quality of life, dyspnea, mood, occurrence of acute exacerbations, engagement in physical activity, exercise self-efficacy, and exercise adherence. Simultaneously, we are conducting a pilot study of group walking. We will enroll 90 persons who will be randomized to one of three arms in a 2:2:1 ratio: Tai Chi, standard care, or group-based walking.

DISCUSSION

The Long-term Exercise After Pulmonary Rehabilitation (LEAP) study is a novel and clinically relevant trial. We will enroll a well-characterized cohort of persons with COPD and will comprehensively assess physiological and psychosocial outcomes. Results of this study will provide the evidence base for persons with COPD to engage in Tai Chi as a low-cost, long-term modality to sustain physical activity in persons who have completed a standard short-term pulmonary rehabilitation program.

TRIAL REGISTRATION

This trial is registered in Clinical Trials.gov, with the ID number of NCT01998724.

Predictors of success for pulmonary rehabilitation in patients awaiting lung transplantation

BACKGROUND

Numerous studies have shown the effectiveness of comprehensive pulmonary rehabilitation (PR) programs in chronic obstructive pulmonary disease (COPD). At present, it is uncertain whether PR is also effective in the management of patients with various diseases awaiting lung transplantation (LTx).

METHODS

In a retrospective clinical preanalysis and postanalysis, we investigated the effects of a 5-week inpatient PR in LTx candidates. We compared data of patients with COPD, α-1-antitrypsin deficiency, interstitial lung disease, or cystic fibrosis before and after PR with regard to exercise capacity (6-min walking distance [6MWD]) and health-related quality of life (HRQL; SF36). Multivariate stepwise regression analysis was performed to detect predictors of PR outcome.

RESULTS

Eight hundred eleven data sets from consecutive patients referred to our PR center before LTx could be analysed (COPD, 360; α-1-antitrypsin deficiency, 127; interstitial lung disease, 195; cystic fibrosis, 69; other, 60). After PR 6MWD increased by 56 ± 58 m (P < 0.001), the physical summary component of SF36 (0-100) improved by 1.9 ± 8.5 points (P < 0.001), the mental summary component of SF36 by 8.7 ± 13.5 points (P < 0.001). Stepwise regression analysis yielded no relevant predictors of success or nonsuccess of PR with regard to age, sex, disease, body mass index, 6MWD, and HRQL on admission.

CONCLUSION

Short-term comprehensive PR can significantly improve exercise capacity and HRQL in LTx candidates to a clinically relevant extent independent of the underlying lung disease. No relevant predictor influencing PR outcome could be detected. Further research is needed to evaluate the relevance of PR before LTx and its impact on clinical outcome after transplantation.

Construct validity and minimal important difference of 6-minute walk distance in survivors of acute respiratory failure

OBJECTIVE

The 6-min walk distance (6MWD), a widely used test of functional capacity, has limited evidence of construct validity among patients surviving acute respiratory failure (ARF) and ARDS. The objective of this study was to examine construct validity and responsiveness and estimate minimal important difference (MID) for the 6MWD in patients surviving ARF/ARDS.

METHODS

For this secondary data analysis of four international studies of adult patients surviving ARF/ARDS (N = 641), convergent and discriminant validity, known group validity, predictive validity, and responsiveness were assessed. MID was examined using anchor- and distribution-based approaches. Analyses were performed within studies and at various time points after hospital discharge to examine generalizability of findings.

RESULTS

The 6MWD demonstrated good convergent and discriminant validity, with moderate to strong correlations with physical health measures (|r| = 0.36-0.76) and weaker correlations with mental health measures (|r| = 0.03-0.45). Known-groups validity was demonstrated by differences in 6MWD between groups with differing muscle strength and pulmonary function (all P < .01). Patients reporting improved function walked farther, supporting responsiveness. 6MWD also predicted multiple outcomes, including future mortality, hospitalization, and health-related quality of life. The 6MWD MID, a small but consistent patient-perceivable effect, was 20 to 30 m. Findings were similar for 6MWD % predicted, with an MID of 3% to 5%.

CONCLUSIONS

In patients surviving ARF/ARDS, the 6MWD is a valid and responsive measure of functional capacity. The MID will facilitate planning and interpretation of future group comparison studies in this population.

Veterans with chronic obstructive pulmonary disease achieve clinically relevant improvements in respiratory health after pulmonary rehabilitation

PURPOSE

To measure respiratory health and respiratory-related (RR) health care utilization in veterans with chronic obstructive pulmonary disease referred to pulmonary rehabilitation (PR) at the Cincinnati Veterans Administration (VA) Medical Center.

METHODS

We reviewed the records of 430 patients referred for PR from 2008 to 2010: 78 met inclusion criteria and completed PR (PR group); 92 qualified for PR but declined participation (referral group). All PR participants completed the St. George's Respiratory Questionnaire (SGRQ), BODE index, 6-minute walk test (6MWT), UCSD Shortness of Breath Questionnaire (UCSDSOBQ), Pulmonary Disease Knowledge Test, and self-reported use of short-acting bronchodilators before and after PR. All VA health care encounters during the 12 months before and after PR (PR group) or referral (referral group) were reviewed.

RESULTS

Respiratory health improved after PR: SGRQ (60.6 ± 15.1, 51.1 ± 16.7), BODE (4.65 ± 1.93, 3.41 ± 1.84), 6MWT (497 ± 367 m, 572 ± 397 m), UCSDSOBQ (68.3 ± 21.1, 61.0 ± 20.9), Pulmonary Disease Knowledge Test (75.9 ± 12.4%, 85.9 ± 11.1%), short-acting bronchodilator (22.5 ± 25.3, 12.8 ± 15.6 inhalations per week) (before, after PR; P < .001 for all comparisons). The RR emergency department (ED) visits (0.71 ± 1.44, 0.44 ± 0.86; P = .04) and RR hospitalizations (0.41 ± 0.73, 0.23 ± 0.51; P = .03) (visits/patient/year; pre-PR, post-PR) decreased following PR. RR ED visits and hospitalizations were the same for the PR and referral groups prior to PR but declined post-PR (0.44 ± 0.86, 0.78 ± 1.36 ED visits/patient/year; P = .05) and (0.23 ± 0.51, 0.59 ± 1.20 hospitalizations/patient/year; P = .01). Ninety-four percent of PR participants achieved the minimal clinically important difference in at least 1 univariate scale (Modified Medical Research Council, UCSDSOBQ, SGRQ, and 6MWT); 82%, 2 scales; 59%, 3 scales; and 24%, all 4 scales.

CONCLUSIONS

Pulmonary rehabilitation improves respiratory health in veterans with chronic obstructive pulmonary disease and decreases RR health care utilization.

Aerobic training and postexercise protein in facioscapulohumeral muscular dystrophy: RCT study

OBJECTIVE

To investigate the effect of regular aerobic training and postexercise protein-carbohydrate supplementation in patients with facioscapulohumeral muscular dystrophy (FSHD).

METHODS

In this randomized, double-blind, placebo-controlled parallel study, we randomized untrained men (n = 21) and women (n = 20) with FSHD (age 19-65 years) to 2 training groups-training with protein supplement (n = 18) and training with placebo supplement (n = 13)-and a nonintervention control group (n = 10). We assessed fitness, walking speed, muscle strength, questionnaires, and daily activity levels before and after 12 weeks of interventions. Training involved 36 sessions of 30-minute cycle-ergometer training. After each session, patients drank either a protein-carbohydrate or placebo beverage.

RESULTS

In the trained participants, fitness, workload, and walking speed improved (10% [confidence interval (CI) 4%-15%], 18% [CI 10%-26%], 7% [CI 4%-11%], respectively, p < 0.001, number needed to treat = 2.1). Self-assessed physical capacity and health (Short Form-36) also improved. Muscle strength and daily activity levels did not change with training. Protein-carbohydrate supplementation did not result in further improvements in any tests compared to training alone.

CONCLUSIONS

This randomized, controlled study showed that regular endurance training improves fitness, walking speed, and self-assessed health in patients with FSHD without causing muscle damage. Postexercise protein-carbohydrate supplementation does not add any further improvement to training effects alone.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that regular aerobic training with or without postexercise protein-carbohydrate supplementation improves fitness and workload in patients with FSHD.

Reproducibility of the six-minute walk test and Glittre ADL-test in patients hospitalized for acute and exacerbated chronic lung disease

Background:

The 6-minute walk test (6MWT) and the Glittre ADL-test (GT) are used to assess functional capacity and exercise tolerance; however, the reproducibility of these tests needs further study in patients with acute lung diseases.

Objectives:

The aim of this study was to investigate the reproducibility of the 6MWT and GT performed in patients hospitalized for acute and exacerbated chronic lung diseases.

Method:

48 h after hospitalization, 81 patients (50 males, age: 52±18 years, FEV₁: 58±20% of the predicted value) performed two 6MWTs and two GTs in random order on different days.

Results:

There was no difference between the first and second 6MWT (median 349 m [284-419] and 363 m [288-432], respectively) (ICC: 0.97; P<0.0001). A difference between the first and second tests was found in GT (median 286 s [220-378] and 244 s [197-323] respectively; P<0.001) (ICC: 0.91; P<0.0001).

Conclusion:

Although both the 6MWT and GT were reproducible, the best results occurred in the second test, demonstrating a learning effect. These results indicate that at least two tests are necessary to obtain reliable assessments.

Smallest worthwhile effect of land-based and water-based pulmonary rehabilitation for COPD

This study aimed to determine the smallest worthwhile effect of land-based and water-based pulmonary rehabilitation on 6-min walk distance among people with chronic obstructive pulmonary disease (COPD). Using a benefit-harm trade-off method, people with COPD who had completed two baseline 6-min walk tests at the commencement of outpatient pulmonary rehabilitation were presented with two scenarios: 8 weeks of land-based and 8 weeks of water-based pulmonary rehabilitation. Participants were guided through an iterative process allowing them to progressively refine their estimates of the smallest improvement due to each form of rehabilitation that would outweigh the associated costs, risks and inconvenience presented in the scenario. 100 people with COPD participated (mean±sd age 72±9 years, forced expiratory volume in 1 s 54±16% predicted and baseline 6-min walk distance 377±101 m). For land-based pulmonary rehabilitation, the median smallest worthwhile effect was 20 m (95% CI 15-37 m). For water-based pulmonary rehabilitation, the median smallest worthwhile effect was 26 m (95% CI 15-33 m). These estimates did not differ significantly (p=0.10). People with COPD typically perceive that pulmonary rehabilitation would be worthwhile if it increased the 6-min walk distance by about 6%. The smallest worthwhile effects of land- and water-based pulmonary rehabilitation were similar.