Changes in the endurance shuttle walk test in COPD patients with chronic respiratory failure after pulmonary rehabilitation: the minimal important difference obtained with anchor- and distribution-based method

Determining the minimum important differences for field walking tests in adults with long-term conditions: a systematic review and meta-analysis

IMPORTANCE

The minimum important difference (MID) for field walking tests aims to improve interpretation of outcomes, but the volume and heterogeneity of MIDs for these tests is challenging. We aimed to determine the MID for the 6-min walk distance (6MWD), incremental shuttle walk test (ISWT) and endurance shuttle walk test (ESWT) in adults with long-term conditions.

METHODS

This systematic review included studies that generated a MID using an anchor-based approach in patients with long-term conditions for the 6MWD, ISWT or ESWT field walking tests. Studies were screened and data extracted by independent reviewers. Meta-analyses were performed using RevMan.

RESULTS

42 studies were included in the analyses, involving n=13 949 participants. Of these, 12 studies involving exercise as an intervention were included in the meta-analyses to produce MIDs, presented as mean (95% confidence interval). The MID for the 6MWD was 25 m (24-26 m) for respiratory conditions, 23 m (8-37 m) for cardiac conditions and 37 m (26-49 m) for neurological/musculoskeletal conditions. The MID for the ISWT was 48 m (39-57 m) for respiratory conditions and 70 m (55-85 m) for cardiac conditions. The MID for ESWT in COPD was 159 s (94-224 s). The pooled MID across conditions within exercise interventions was 26 m (22-40 m) for the 6MWD and 53 m (44-62 m) for the ISWT, with reasonable heterogeneity (I2=48% and I2=47%, respectively).

CONCLUSION

We propose new MIDs for exercise interventions using anchor-based methodology in long‑term conditions for the 6MWD, ISWT and ESWT. These can be used internationally for meta‑analyses where studies have used different field walking tests, to optimise trial sample size calculations, and for clinical service benchmarking.

Minimum important difference of shuttle walk tests in patients with interstitial lung disease following pulmonary rehabilitation

Background

Pulmonary rehabilitation (PR) is recommended for patients with interstitial lung disease (ILD). The impact of PR on exercise capacity, symptom management and mortality risk in ILD is well established; however, there are limited studies reporting on the minimal important difference (MID) for shuttle walk tests (SWTs) in the ILD population. The aim of this study was to establish the MID for both the incremental and endurance shuttle walking tests (ISWT/ESWT) in the ILD population and to evaluate the association with survival.

Participants

The study includes 207 participants with ILD (mean±sd age 71.1±9.5 years, forced vital capacity 2.32±0.79 L) who completed PR.

Results

The baseline ISWT was 251.4±153.3 m and ESWT was 217.7±136.3 s. There were significant improvements for both the ISWT and ESWT following the PR programme (44.5±77.0 m (p<0.001) and 312.3±338.6 s (p<0.001)). MID was calculated through a combination of distribution (0.5×sd) and anchor-based techniques (global rating of change (GROC) and receiver operating characteristic (ROC) analysis). The distribution-based technique yielded an MID of 38.5 m for ISWT and 169.3 s for ESWT. ROC analyses yielded an MID of 35 m for ISWT and 200 s for ESWT; and the GROC yielded an MID of 58.5 m for ISWT and 209.0 s for ESWT. Survival analysis showed that improvements in exercise tolerance are associated with improved survival.

Conclusion

Our data suggest an MID of 35.0-38.5 m for ISWT and 170-209 s for ESWT for patients with ILD. The size of improvements in SWT is associated with a survival advantage in ILD individuals who attend and complete PR.

Effectiveness of Water-Based Exercise in Patients with Chronic Obstructive Pulmonary Disease: Systematic Review and Meta-Analysis

Chronic obstructive pulmonary disease (COPD) is a progressive respiratory disease that, due to dyspnea, decreases patients' physical function and quality of life. The aim of the research was to evaluate the effectiveness of water-based exercise (WE) in improving functional capacity and respiratory muscle strength in patients with COPD. It consisted of a systematic review and meta-analysis of eight randomized clinical trials (RCTs) from the last 10 years, found in PubMed, PEDro, Scopus and Web of Science databases. Methodological quality was analyzed using the PEDro scale and the Cochrane Collaboration Risk of Bias Tool. Regarding the evaluation of functional capacity, mainly assessed were lung function, respiratory muscle strength, and maximal or aerobic exercise. The results showed that WE improves functional capacity compared to a non-exercising control group (SMD: 73.42; IC 95%: 40.40 to 106.45; I2: 0%). There are no statistically significant differences between a WE treatment and a land exercise (LE) treatment (p = 0.24) in functional capacity, nor with respect to respiratory muscle strength (p = 0.97). These data should be interpreted with caution, as more RCTs with aquatic intervention in COPD patients are needed to elucidate whether there are differences between WE or LE according to patient characteristics and comorbidities.

The Role of Pulmonary Function Testing in the Diagnosis and Management of COPD

Pulmonary function testing (PFT) has a long and rich history in the definition, diagnosis, and management of COPD. For decades, spirometry has been regarded as the standard for diagnosing COPD; however, numerous studies have shown that COPD symptoms, pathology, and associated poor outcomes can occur, despite normal spirometry. Diffusing capacity and imaging studies have called into question the need for spirometry to put the "O" (obstruction) in COPD. The role of exercise testing and the ability of PFTs to phenotype COPD are reviewed. Although PFTs play an important role in diagnosis, treatment decisions are primarily determined by symptom intensity and exacerbation history. Although a seminal study positioned FEV1 as the primary predictor of survival, numerous studies have shown that tests other than spirometry are superior predictors of mortality. In years past, using spirometry to screen for COPD was promulgated; however, this only seems appropriate for individuals who are symptomatic and at risk for developing COPD.

Reliability and Responsiveness of Endurance Shuttle Walk Test to Estimate Functional Exercise Capacity in Patients with Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-analysis

The endurance shuttle walk test (ESWT) is a simple, acceptable, field-based test first established in 1999 to measure endurance exercise capacity in patients with chronic obstructive pulmonary disease (COPD). The aim of this systematic review was to examine the reliability and responsiveness of ESWT in COPD. Of the 791 articles identified through electronic databases, 17 were included in this review. Qualitative and quantitative analyses were conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses, and as per Consensus-Based Standards for the Selection of Health Status Measurements Instruments, the quality of the studies was graded as low for reliability and moderate for responsiveness. Qualitative analysis indicated inadequate evidence for the reliability of the ESWT in patients with COPD. The meta-analysis found strong evidence that ESWT was responsive to change following pulmonary rehabilitation with an estimated mean difference (ESWT time, seconds) 303.19 s (95% CI: 175.63-430.75; p< 0.001), ambulatory oxygen with a mean difference (ESWT time, seconds) 129.04 s (95% CI: 47.98-210.09; p = 0.002), and (ESWT mean distance, meters) 80.71 m (95% CI: 38.66-122.76; p < 0.001). The ESWT was also responsive to bronchodilation with a mean difference of 168.62 m (95% CI: 117.03-220.21; p < 0.001). Our findings suggest the strong potential of ESWT as a responsive test in COPD, but to draw a definitive conclusion regarding the reliability of the ESWT, further research is needed in this population.

Rehabilitation effects of land and water-based aerobic exercise on lung function, dyspnea, and exercise capacity in patients with chronic obstructive pulmonary disease: A systematic review and meta-analysis

BACKGROUND

We sought to synthesize the evidence about aerobic exercise intervention during pulmonary rehabilitation, and to further explore the difference in rehabilitation effects between water and land-based aerobic exercise. This review's purpose is to provide a basis by which practitioners and therapists can select and create appropriate therapeutic programs.

METHODS

Data of randomized and quasi-randomized controlled trials comparing training group (TG, aerobic exercise in water or land) and control group (CG, usual care) in chronic obstructive pulmonary disease (COPD) patients (January 1, 2000-December 28, 2019) were obtained from the Cochrane Library, PubMed, Embase, China National Knowledge Infrastructure, and Wanfang databases. Two researchers independently reviewed the literature, extracted the data, and evaluated the quality of the literature. Review Manager software (Rev Man 5.3; Cochrane, London, UK) was used for meta-analysis. The rehabilitation effect of water- or land based aerobic exercise was evaluated by subgroup analysis. The proposed systematic review details were registered in PROSPERO (CRD 42020168331).

RESULTS

Eighteen studies (1311 cases of COPD) were included. Meta-analysis results show that compared with the control group, the dyspnea level and functional and endurance exercise capacity in COPD patients were significantly improved after aerobic exercise (P < .05), but there was no significant change in lung function (P > .05). Compared with land-based aerobic exercise, water-based aerobic exercise significantly improved the endurance exercise capacity in COPD patients (mean difference [MD]: 270.18, 95% CI: 74.61-465.75).

CONCLUSION

Medium to high-quality evidence shows that aerobic exercise can effectively improve dyspnea and exercise capacity in COPD patients. Compared with land-based aerobic exercise, water-based aerobic exercise had a significant additional effect in improving the endurance exercise capacity of COPD patients.

Correlates of variability in endurance shuttle walk test time in patients with chronic obstructive pulmonary disease

Background

The endurance shuttle walk test (ESWT) is used to evaluate exercise tolerance in patients with chronic obstructive pulmonary disease (COPD). The recommended pre-intervention tolerated duration (Tlim) is between 3–8 minutes for optimal interpretation of treatment effects. However, this window may be exceeded and factors determining ESWT Tlim are not completely understood. Therefore, we aimed to determine whether pulmonary function, physical and incremental shuttle walk test (ISWT) performance measures are associated with ESWT Tlim in COPD patients.

Methods

Assessment data from patients eligible for pulmonary rehabilitation was retrospectively analyzed. Inclusion criteria were: diagnosis of COPD and complete data availability regarding ESWT and ISWT. Patients performed an ESWT at 85% of ISWT speed and were divided into three groups (ESWT Tlim: <3 minutes, 3–8 minutes, >8 minutes). Subject characteristics, severity of complaints, pulmonary function, physical capacity and activity, exercise tolerance and quadriceps muscle strength were evaluated.

Results

245 COPD patients (FEV₁ 38 (29–52)% predicted) were included. Median ESWT Tlim was 6.0 (3.7–10.3) minutes, 41 (17%) patients walked <3 minutes and 80 (33%) patients walked >8 minutes. Body mass index, maximal oxygen consumption, Tlim on constant work rate cycle test, physical activity level, maximal ISWT speed, dyspnoea Borg score at rest and increase of leg fatigue Borg score during ISWT independently predicted Tlim in multivariate regression analysis (R² = 0.297, p<0.001).

Conclusion

This study reported a large variability in ESWT Tlim in COPD patients. Secondly, these results demonstrated that next to maximal ISWT speed, other ISWT performance measures as well as clinical measures of pulmonary function, physical capacity and physical activity were independent determinants of ESWT Tlim. Nevertheless, as these determinants only explained ~30% of the variability, future studies are needed to establish whether additional factors can be used to better adjust individual ESWT pace in order to reduce ESWT Tlim variability.

[Which physical tests for which objectives in pulmonary rehabilitation?]

Chronic respiratory disease is a major cause of morbidity and mortality worldwide and an important cause of disability including a reduction of exercise, functional and muscle capacity contributing to a decreased quality of life. In the context of pulmonary rehabilitation, a thorough patient-centered outcome assessment, including not only measures of lung function, but also exercise functional and muscle capacity, is imperative for a comprehensive disease management. Assessment of these impairments and dysfunctions with appropriate and change-sensitive procedures is thus necessary for personalizing the physical interventions and assessing the short- and long-term effectiveness of the intervention. The clinician currently has a wide variety of tests and measurements available to assess the physical and functional capacity of people with chronic respiratory disease. The aim of this review is to provide a pragmatic synthesis of the physical, functional and muscle capacity tests most commonly used in pulmonary rehabilitation. Ultimately, it should help the clinician to identify the relevant evaluations according to the objectives of the patients but also according to the available resources, the setting of pulmonary rehabilitation and the specific qualities of each test.

Adherence to early pulmonary rehabilitation after COPD exacerbation and risk of hospital readmission: a secondary analysis of the COPD-EXA-REHAB study

Background

Early pulmonary rehabilitation after exacerbation of chronic obstructive pulmonary disease (COPD) has previously been shown to reduce the risk of hospital admission and improve physical performance and quality of life. However, the impact of attendance at early rehabilitation programmes has not been established.

Objectives

To evaluate the impact of increasing attendance to pulmonary rehabilitation on the risk of hospital admission, physical performance and quality of life in patients attending an early rehabilitation programme after an exacerbation of COPD.

Methods

This study was a secondary exploratory analysis of the randomised controlled trial COPD-EXA-REHAB study, involving patients hospitalised with an exacerbation of COPD. The COPD-EXA-REHAB study compared early pulmonary rehabilitation, starting within 2 weeks after an exacerbation, with standard treatment, that is, the same programme starting 2 months later. The present analysis included only the 70 patients allocated to early pulmonary rehabilitation.

Results

At 1-year follow-up, we found an association between the number of sessions attended and a reduction in hospital admissions (incidence rate ratio 0.93 (95% CI 0.88 to 0.99), p=0.02), corresponding to a 7% reduction for each session attended. Similarly, at 2-month follow-up, physical performance was positively associated with sessions attended: the mean Incremental Shuttle Walk Test result improved by 8 m with each session (95% CI 2.54 to 13.56, p=0.005) and the Endurance Shuttle Walk Test result by 44 s (95% CI 18.41 to 68.95, p=0.001). Quality of life, assessed using the COPD Assessment Test, was not significantly associated with the number of attended sessions, with the average score increasing by 0.15 points with each session (95% CI −0.35 to 0.65, p=0.55).

Conclusion

Increased attendance at early pulmonary rehabilitation after exacerbation of COPD was associated with reduced risk of hospital admission and improved physical performance.

Early pulmonary rehabilitation after acute exacerbation of COPD: a randomised controlled trial

Objectives

The aim of this study was to establish whether early pulmonary rehabilitation after severe exacerbation of chronic obstructive pulmonary disease (COPD) reduces mortality and hospital admissions, and increases physical performance and quality of life compared to rehabilitation initiated later in the stable phase of COPD.

Methods

In a randomised controlled trial of 150 patients hospitalised with an exacerbation of COPD, participants were allocated to pulmonary rehabilitation either within 2 weeks after discharge or the same rehabilitation programme but initiated 2 months after discharge.

Results

Early pulmonary rehabilitation did not prolong time to first hospital admission or time to death (hazard ratio 0.79, 95% CI 0.47–1.23, p=0.33) compared to rehabilitation in stable phase. However, 2 months after inclusion, pulmonary rehabilitation resulted in a significantly better improvement in the incremental shuttle walk test (33.9 m, 95% CI 4.18–63.7, p=0.02) compared to that in the stable phase. The difference in the endurance shuttle walk test was of borderline significance (140 s, 95% CI −2.03–282.76, p=0.05), but there was no significant difference concerning the COPD assessment test (−1.43 points, 95% CI −3.44–0.59, p=0.17).

Conclusion

Early pulmonary rehabilitation after acute exacerbation of COPD led to a faster improvement in physical performance compared to rehabilitation initiated later in the stable phase, but did not improve survival or prolong time to hospital readmission.

Early pulmonary rehabilitation shortly after #AECOPD leads to a faster recovery in physical performance than initiated in the stable phase. Adherence to rehabilitation is significantly higher when initiated shortly after an exacerbation.http://bit.ly/2S7XsT9

Exercise Training in Patients with Chronic Respiratory Diseases: Are Cardiovascular Comorbidities and Outcomes Taken into Account?-A Systematic Review

Patients with chronic obstructive pulmonary disease (COPD), asthma and interstitial lung diseases (ILD) frequently suffer from cardiovascular comorbidities (CVC). Exercise training is a cornerstone intervention for the management of these conditions, however recommendations on tailoring programmes to patients suffering from respiratory diseases and CVC are scarce. This systematic review aimed to identify the eligibility criteria used to select patients with COPD, asthma or ILD and CVC to exercise programmes; assess the impact of exercise on cardiovascular outcomes; and identify how exercise programmes were tailored to CVC. PubMed, Scopus, Web of Science and Cochrane were searched. Three reviewers extracted the data and two reviewers independently assessed the quality of studies with the Quality Assessment Tool for Quantitative Studies. MetaXL 5.3 was used to calculate the individual and pooled effect sizes (ES). Most studies (58.9%) excluded patients with both stable and unstable CVC. In total, 26/42 studies reported cardiovascular outcomes. Resting heart rate was the most reported outcome measure (n = 13) and a small statistically significant effect (ES = -0.23) of exercise training on resting heart rate of patients with COPD was found. No specific adjustments to exercise prescription were described. Few studies have included patients with CVC. There was a lack of tailoring of exercise programmes and limited effects were found. Future studies should explore the effect of tailored exercise programmes on relevant outcome measures in respiratory patients with CVC.

The minimal important difference for the endurance shuttle walk test in individuals with chronic obstructive pulmonary disease following a course of pulmonary rehabilitation

The endurance shuttle walk test (ESWT) is frequently used as an outcome measure for pulmonary rehabilitation (PR). The minimal important difference (MID) for the ESWT after a course of rehabilitation has not been conclusively confirmed in the literature. The aim was to establish the MID for the ESWT following the 6-week PR programme in patients with chronic obstructive pulmonary disease (COPD). Following the completion of the 6-week PR programme, data from 531 participants were included in the analysis to estimate the MID for the ESWT using both anchor-based and distribution-based methods. Mean age (standard deviation (SD)) was 69.4 (9.1) years, 303 male, FEV₁/FVC 0.51 (0.16). The baseline incremental shuttle walk test (ISWT) was 217.7 (SD 139.8) metres and ESWT 195.8 (SD 118.8) seconds, which increased to 279.6 (SD 149.5) metres and 537.4 (SD 378.3) seconds, respectively, following PR. The mean change was 61.8 (95% confidence interval (CI) 56.0–67.5) metres for the ISWT and 342.0 (95% CI 312.4–371.6) seconds for the ESWT. The distribution method (0.5 × SD) yielded an MID of 173.7 seconds, the global rating of change scale method yielded a value of 279.2 (95% CI 244.9–313.5) seconds for those rating themselves as ‘slightly improved’ and the ROC method 207 seconds. There was no agreement between the approaches employed. However, we propose that the MID for the ESWT in COPD following a 6-week PR programme is between 174 and 279 seconds.

People With COPD Who Respond to Ground-Based Walking Training Are Characterized by Lower Pre-training Exercise Capacity and Better Lung Function and Have Greater Progression in Walking Training Distance

PURPOSE

To investigate the characteristics that distinguish responders from nonresponders to ground-based walking training (GBWT) in people with chronic obstructive pulmonary disease (COPD).

METHODS

An analysis was undertaken of data collected during a trial of GBWT in people with COPD. Responders to GBWT were defined in 2 ways: (1) improved time on the endurance shuttle walk test of ≥190 sec (criterion A); or (2) improved ability to walk, perceived by the participant to be at least "moderate" (criterion B). Differences in participant characteristics, pre-training exercise capacity, health-related quality of life, and the improvement in the distance walked during the training program were examined between responders and nonresponders.

RESULTS

Of the 95 participants randomized to GBWT (age 69 ± 8 yr, forced expiratory volume in 1 sec [FEV1] % predicted = 43% ± 15%), data were available for analysis on 78 and 73 patients by criterion A and criterion B, respectively. According to criterion A, 32 (41%) participants were responders. The odds of being a responder increased with increasing FEV1 % predicted (OR = 1.2; 95% CI, 1.0-1.5, for every 5% increase) and increased with decreasing pre-training incremental shuttle walk distance (OR = 1.4; 95% CI, 1.0-1.8, for every 50-m decrement). According to criterion B, 42 (58%) participants were responders. There were no differences in characteristics or pre-training measures between the responders and nonresponders. For both criteria, responders demonstrated greater change in the distance walked during the training program (P < .05).

CONCLUSION

Responders to GBWT had lower pre-training exercise capacity, had better lung function, and demonstrated greater change in the distance walked during the training program.

Unravelling the mystery of the 'minimum important difference' using practical outcome measures in chronic respiratory disease

It is important for clinicians and researchers to understand the effects of treatments on their patients, both at an individual and group level. In clinical studies, treatment effects are often reported as a change in the outcome measure supported by a measure of variability; for example, the mean change with 95% confidence intervals and a probability ( p) value to indicate the level of statistical significance. However, a statistically significant change may not indicate a clinically meaningful or important change for clinicians or patients to interpret. The minimum clinically important difference (MCID) or minimally important difference (MID) has therefore been developed to add clinical relevance or patient experience to the reporting of an outcome measure. In this article, we consider the concept of the MID using the example of practical outcome measures in patients with CRD. We describe the various ways in which an MID can be calculated via anchor- and distribution-based methods, looking at practical examples and considering the importance of understanding how an MID was derived when seeking to apply it to a particular situation. The terms MID and MCID are challenging and often used interchangeably. However, we propose all MIDs are described as such, but they could be qualified by a suffix: MIDS (MID - Statistical), MID-C (MID - Clinical outcome), MID-P (MID - Patient determined). However, this type of classification would only work if accepted and adopted. In the meantime, we advise clinicians and researchers to use an MID where possible to aid their interpretation of functional outcome measures and effects of interventions, to add meaning above statistical significance alone.

The Impact of Listening to Music During a High-Intensity Exercise Endurance Test in People With COPD

BACKGROUND

In people with COPD, dyspnea is the primary symptom limiting exercise tolerance. One approach to reducing dyspnea during exercise is through music listening. A constant speed endurance test reflects a high-intensity aerobic exercise training session, but whether listening to music affects endurance time is unknown. This study aimed to determine the effects of listening to music during a constant speed endurance test in COPD.

METHODS

Participants with COPD completed two endurance walk tests, one with and one without listening to self-selected music throughout the test. The primary outcome was the difference in endurance time between the two conditions. Heart rate, percutaneous oxygen saturation, dyspnea, and rate of perceived exertion were measured before and after each test.

RESULTS

Nineteen participants (mean [SD]: age, 71 [8] years; FEV₁, 47 [19] % predicted) completed the study. Endurance time was greater (1.10 [95% CI, 0.41-1.78] min) while listening to music (7.0 [3.1] min) than without (5.9 [2.6] min), and reduced end-test dyspnea (1.0 [95% CI, -2.80 to -1.80] units) (with music, 4.6 [1.7] units; vs without music, 5.6 [1.4] units, respectively). There was not a significant difference in heart rate, percutaneous oxygen saturation, or leg fatigue. There were no adverse events under either condition.

CONCLUSIONS

In COPD, dyspnea was less while listening to music and was accompanied by an increased tolerance of high-intensity exercise demonstrated by greater endurance time. Practically, the effect was modest but may represent an aid for exercise training of these patients.

TRIAL REGISTRY

Australian New Zealand Clinical Trials Registry; No. ACTRN12617001217392.

Non-invasive ventilation during cycle exercise training in patients with chronic respiratory failure on long-term ventilatory support: A randomized controlled trial

BACKGROUND AND OBJECTIVE

The role of non-invasive ventilation (NIV) during exercise training (ET) in patients with chronic respiratory failure (CRF) is still unclear. The aim of this study was to test whether NIV during ET had an additional effect in increasing the 6-min walking distance (6MWD) and cycle endurance time compared with ET alone.

METHODS

All patients underwent 20 sessions of cycle training over 3 weeks and were randomly assigned to ET with NIV or ET alone. Outcome measures were 6MWD (primary outcome), incremental and endurance cycle ergometer exercise time, respiratory muscle function, quality of life by the Maugeri Respiratory Failure questionnaire (MRF-28), dyspnoea (Medical Research Council scale) and leg fatigue at rest.

RESULTS

Forty-two patients completed the study. Following training, no significant difference in 6MWD changes were found between groups. Improvement in endurance time was significantly greater in the NIV group compared with the non-NIV training group (754 ± 973 vs 51 ± 406 s, P = 0.0271); dyspnoea improved in both groups, while respiratory muscle function and leg fatigue improved only in the NIV ET group. MRF-28 improved only in the group training without NIV.

CONCLUSION

In CRF patients on long-term NIV and long-term oxygen therapy (LTOT), the addition of NIV to ET sessions resulted in an improvement in endurance time, but not in 6MWD.

Minimal important difference of target lobar volume reduction after endobronchial valve treatment for emphysema

BACKGROUND AND OBJECTIVE

Target lobar volume reduction (TLVR) is an important efficacy outcome measure for bronchoscopic lung volume reduction (BLVR) treatment using one-way endobronchial valves (EBV) in patients with severe emphysema. The commonly used cut-off value for TLVR that expresses a perceivable clinical benefit is -350 mL. However, a scientifically determined minimal important difference (MID) for TLVR never has been published. The objective of the present study was to determine the MID for TLVR on HRCT in patients who were treated with EBV.

METHODS

A total of 318 patients with severe emphysema from two BLVR trials were analysed. Anchor-based methods were used to define the TLVR MID at 6 months follow-up. Forced expiratory volume in 1 s (FEV₁ ), residual volume (RV) and St. George's Respiratory Questionnaire (SGRQ) were used as anchors.

RESULTS

The calculated TLVR MID with each anchor was: FEV₁ -587 mL, RV -534 mL and SGRQ -560 mL. The combined MID (average of the three anchor-based MIDs) was -563 mL.

CONCLUSION

Using the anchor-based method, we established a TLVR MID of -563 mL in patients with severe emphysema at 6 months follow-up after EBV treatment. This value can be useful for both interpreting the results from trials and clinical practice, as well as for designing future studies on lung volume reduction.

Efficacy of a multidisciplinary pulmonary rehabilitation outpatient program on exacerbations in overweight and obese patients with asthma

BACKGROUND

Even though many studies have investigated the effectiveness of weight loss interventions, the efficacy of pulmonary rehabilitation (PR) has not yet been proven in obese patients with asthma. The aims of this study were to investigate the efficacy of PR on asthma exacerbations in the first year after PR and to evaluate the efficacy of PR in exercise capacity, quality of life, psychosocial symptoms and control of asthma in overweight patients.

METHODS

The exercise capacity, health-related quality of life scores, psychosocial symptoms, asthma control test (ACT) data, number of emergency admissions and hospitalizations of 35 overweight patients with asthma who completed a 1-year multidisciplinary PR program were recorded and analyzed.

RESULTS

Of the participants 30 were female, the mean age was 45 ± 9 years, 13 (37%) patients were overweight and 22 (63%) were obese. The average number of emergency admissions (from 1.2 ± 1.1 to 0.3 ± 0.8) and hospitalizations (from 0.6 ± 0.9 to 0.0 ± 0.1) decreased significantly 1 year after PR (both p<0.001). After PR, statistically significant improvements in exercise capacity as measured by the incremental shuttle walking test (ISWT) from 281 ± 104 m to 339 ± 95 m (p < 0.001), the endurance shuttle walking test (ESWT) from 13.3 ± 7.4 min to 17.5 ± 4.5 min (p = 0.005), quality of life measured by the St. George's respiratory questionnaire (SGRQ total from 64 ± 14 to 28 ± 10, p < 0.001), dyspnea sensation with the Medical Research Council (MRC) scale (from 2.6 ± 0.6 to 2.1 ± 0.4, p <0.001) and hospital anxiety depression scores (HADS, anxiety score from 9.9 ± 1.6 to 7.1 ± 2.1, depression score from 9.4 ± 1.9 to 7.2 ± 2.3, both p < 0.001) were found. A reduction in body mass index (BMI) was found in obese patients only, but the fat-free mass index (FFMI) improved in both overweight and obese patients (from 19.00 ± 1.90 to 19.45 ± 2.04, p = 0.01). The mean ACT score increased significantly (from 18 to 21 points, p < 0.001). The number of patients with poorly controlled asthma decreased from 21 (60%) to 10 (28%).

CONCLUSION

This study showed that comprehensive multidisciplinary PR was associated with a decreased number of emergency admissions and hospitalizations for asthma exacerbations in 1 year, and improvements of dyspnea sensation, quality of life, exercise capacity, and psychosocial status in overweight and obese patients.

Reliability and validity of an audio signal modified shuttle walk test

Background:

The audio signal in the conventionally accepted protocol of shuttle walk test (SWT) is not well-understood by the patients and modification of the audio signal may improve the performance of the test.

Objectives:

The aim of this study is to study the validity and reliability of an audio signal modified SWT, called the Singla-Richa modified SWT (SWT_SR), in healthy normal adults.

Patients and Methods:

In SWT_SR, the audio signal was modified with the addition of reverse counting to it. A total of 54 healthy normal adults underwent conventional SWT (CSWT) at one instance and two times SWT_SR on the same day. The validity was assessed by comparing outcomes of the SWT_SR to outcomes of CSWT using the Pearson correlation coefficient and Bland–Altman plot. Test-retest reliability of SWT_SR was assessed using the intraclass correlation coefficient (ICC). The acceptability of the modified test in comparison to the conventional test was assessed using Likert scale.

Results:

The distance walked (mean ± standard deviation) in the CSWT and SWT_SR test was 853.33 ± 217.33 m and 857.22 ± 219.56 m, respectively (Pearson correlation coefficient - 0.98; P < 0.001) indicating SWT_SR to be a valid test. The SWT_SR was found to be a reliable test with ICC of 0.98 (95% confidence interval: 0.97–0.99). The acceptability of SWT_SR was significantly higher than CSWT.

Conclusions:

The SWT_SR with modified audio signal with reverse counting is a reliable as well as a valid test when compared with CSWT in healthy normal adults. It better understood by subjects compared to CSWT.

The minimal important difference for the St George's Respiratory Questionnaire in patients with severe COPD

The St George's Respiratory Questionnaire (SGRQ) is a validated, commonly used questionnaire for measuring quality of life in patients with chronic obstructive pulmonary disease (COPD). The current established minimal important difference (MID) for SGRQ scores in an average COPD population is -4 units. However, for patients with severe COPD, the MID has not been thoroughly validated. We re-determined the SGRQ MID for this patient group.115 severe COPD patients (forced expiratory volume in 1 s (FEV1) 26±9% of predicted, SGRQ score 62±11 units; mean±sd,) who participated in seven different bronchoscopic lung volume reduction clinical trials were included in the analysis. Anchor- and distribution-based methods were used to define the MID for SGRQ scores. FEV1, 6-min walk distance and residual volume were used as anchors.Combining both anchor- and distribution-based methods, we identified a SGRQ MID of -8.3 units at 1 month and -7.1 units at 6 months.This study proposes an alternative SGRQ MID for patients with severe COPD of -8.3 units at 1 month and -7.1 units at 6 months follow-up after intervention. Our new MID estimates could be applied for both interpreting SGRQ outcomes as well as sample size determination in future clinical trials investigating interventions in severe COPD patients.