Slow chest compression acutely reduces dynamic hyperinflation in people with chronic obstructive pulmonary disease: a randomized cross-over trial.

BACKGROUND: Strategies to minimize dynamic hyperinflation (DH) and dyspnea, such as slow chest compression (SCC), are relevant in people with chronic obstructive pulmonary disease (COPD). OBJECTIVES: To analyze the acute effects of SCC after exercise on DH and dyspnea in people with COPD and to identify responders to the technique. METHODS: This is a cross-over study with 40 patients. Two six-minute step tests (6MSTs) were performed followed by a one-minute application of SCC (6MSTSCC) or rest (6MSTCONTROL), at random. End-expiratory lung volume (EELV) and dyspnea were assessed. A difference ≥76 ml in ΔEELV between SCC and control characterized the responders. RESULTS: The performance in 6MSTSCC and 6MSTCONTROL were similar. There was a greater reduction in EELV after 6MSTSCC compared to 6MSTCONTROL (124 ± 193 ml vs. 174 ± 183 ml; p = .049), while there was no difference in change in dyspnea between the SCC and control groups. Twenty-one participants were SCC responders and had higher functional residual capacity [FRC: 5.36 ± 1.09 vs. 4.58 ± 0.94; p = .02; cutoff point: 4.56; sensitivity = 76%; specificity = 53%; AUC = 0.71 (95%CI: 0.54 to 0.87); p = .02]. CONCLUSION: SCC applied immediately after exercise reduced DH, but did not reduce dyspnea in people with COPD. The technique is beneficial only for some patients and FRC can help to identify them.

Functional Tests As Predictors Of Balance, Fear, And Risk Of Falling In Healthy Subjects.

OBJECTIVE: Verify which test, Glitttre-ADL test (TGlittre) or six-minute walk test (6MWT), better predicts balance, fear, and risk of falling in middle-aged and older adults. METHOD: Twenty-eight individuals (15 women) completed the study protocol, which included: anthropometric assessment, spirometry, Falls Efficacy Scale-International-Brazil (FES-I-Brazil), Activities-specific Balance Confidence Scale (ABC), Timed Up and Go Test (TUG), Berg Balance Scale (BBS), TGlittre, and 6MWT. The Shapiro Wilk test investigated the distribution of the data. To verify if there was a correlation between the performance in TGlittre and 6MWT and the balance, fear, and risk of falling variables, the Pearson or Spearman correlation coefficient were used. Simple linear regression and stepwise multiple linear regression were conducted to identify which functional capacity test better predicts balance, fear, and risk of falling. RESULTS: Both TGlittre and 6MWT correlated (r = 0.44, p = .02 and r = -0.59, p = .003, respectively) and were able to predict the TUG (R2 = 0.17 and R2 = 0.26, p < .005, respectively). However, when analyzed in a multiple regression model, the 6MWT was better predictor of TUG (26%). Only TGlittre correlated (r = 0.39 and r = -0.38, p = .04) and was able to predict the FES-I-Brazil and BBS scores (17%), suggesting that TGlittre better reflects the worry about falls and balance in multiple ADL contexts. CONCLUSIONS: The 6MWT and the TGlittre are able to predict balance assessed by the TUG. However, the 6MWT has proved to be more effective in predicting TUG results.

Performance in the Glittre-ADL Test is Associated with the Pulmonary Function of Patients with Chronic Obstructive Pulmonary Disease.

The relationship between lung function and performance in some functional tests, as the six-minute walk test (6MWT) and Glittre-ADL test (TGlittre) are still discrepant in patients with chronic obstructive pulmonary disease (COPD). This study aimed to verify which test better correlates and is better explained by the pulmonary function, and which test better discriminates patients regarding the severity of the disease. Seventy-four patients with moderate to very severe COPD (54 men; 66 ± 9 years; FEV1: 37.2 ± 14.3%pred) were included. Spirometry, 6MWT and TGlittre were performed. The results showed weak to moderate correlation between pulmonary function variables and 6MWT (0.36 ≤ r ≤ 0.45) and TGlittre (-0.44 ≤ r ≤ -0.53). In patients with performance of ≤400 m in the 6MWT, a strong correlation was observed between TGlittre with FEV1 (%pred) (r = -0.82; p < .001). The pulmonary function variable that better predict the functional tests performance was FEV1 (R2 = 0.17). Both functional tests were able to discriminate patients with COPD GOLD 4 from the other classifications. When compared to GOLD 2 patients, GOLD 4 patients presented higher time spent on TGlittre (p < .001). When compared to GOLD 3 patients, GOLD 4 patients had higher TGlittre (p = .001). No statistical differences were found in the 6MWT between GOLD 3 and 4, as well as between GOLD 2 and 3. In conclusion, the pulmonary function presents stronger correlations and better explain the variability of TGlittre than of the 6MWT, especially in patients with greater functional impairment. The TGlittre seems to better discriminate patients with COPD regarding the severity of lung function.

Modified Medical Research Council and COPD Assessment Test Cutoff Points.

BACKGROUND: The modified Medical Research Council (mMRC) and COPD Assessment Test (CAT) are assessment instruments associated with level of physical activity of daily living (PADL) in patients with COPD. This study aimed to identify mMRC and CAT cutoff points to discriminate sedentary behavior and PADL level of subjects with COPD and verify whether these cutoff points differentiate pulmonary function, health-related quality of life (HRQOL), functional status, and mortality index in subjects with COPD. METHODS: Subjects (N = 131, FEV1: 36.7 ± 16.1% predicted) were assessed for lung function, mMRC, CAT, HRQOL, functional status, and mortality index. PADL was monitored using a triaxial accelerometer, and subjects were classified as sedentary/nonsedentary (cutoff point of 8.5 h/d in PADL < 1.5 metabolic equivalent of task [MET]), physically active/inactive (cutoff point of 80 min/d in PADL ≥ 3 METs), and with/without severe physical inactivity (cutoff point of 4,580 steps/d), according to variables provided by accelerometer. RESULTS: ROC curve indicated mMRC cutoff point of ≥ 2 (P < .05) for physical inactivity (sensitivity = 66%, specificity = 56%, AUC = 0.62), severe physical inactivity (sensitivity = 81%, specificity = 66%, AUC = 0.76), and sedentary behavior (sensitivity = 61%, specificity = 70%, AUC = 0.65). The identified CAT cutoff points were ≥ 16 and ≥ 20, considering severe physical inactivity (sensitivity = 76%, specificity = 54%, AUC = 0.69, P < .001) and sedentary behavior (sensitivity = 51%, specificity = 90%, AUC = 0.71, P = .001), respectively. Subjects who had mMRC ≥ 2 and CAT ≥ 16 or ≥ 20 presented worse pulmonary function, HRQOL, functional status, and mortality index compared with those who scored mMRC < 2 and CAT <16 or < 20. CONCLUSIONS: mMRC cutoff point of ≥ 2 is recommended to discriminate PADL level and sedentary behavior, whereas CAT cutoff points of ≥ 16 and ≥ 20 discriminated severe physical inactivity and sedentary behavior, respectively. These cutoff points differentiated subjects with COPD regarding all the outcomes assessed in this study.

Reliability and Learning Effect of the Glittre ADL-Test in Patients with Chronic Obstructive Pulmonary Disease.

The Glittre ADL-test (TGlittre) is a multiple-task test designed to assess functional limitation in patients with chronic obstructive pulmonary disease (COPD). Although few studies have investigated the TGlittre learning effect, the results are still conflicting. This study aimed to investigate the test-retest reliability and learning effect on TGlittre and to identify predicting factors of the learning effect in patients with COPD. Patients performed the TGlittre twice with a 30-minutes resting period between trials. TGlittre consists in measuring the time to complete five laps of a multiple ADL-like activities circuit: walking stairs, carrying a backpack, lifting objects, bending down and rising from a seated position. 124 patients with COPD were assessed [81 men; 66 ± 8 years, forced expiratory volume in one second (FEV1) 37.1 ± 15.0%pred; TGlittre 120 ± 60%pred; six-minute walking test 75.5 ± 17.4%pred]. The time spent in TGlittre presented excellent reliability (ICC = 0.96; 95%CI 0.92 - 0.98; p < 0.001; SEM 0.46 min; MDC 1.28 min) and decreased in the retest (5.24 ± 2.31 min to 4.85 ± 2.02 min; p < 0.001). Patients presented a learning effect of 6.11 ± 11.1% in TGlittre. A lower FEV1 (r2=0.10; p < 0.001) and a worse performance in the first TGlittre (r2=0.28; p < 0.001) are related to the improvement in performance of the second TGlittre. Although the TGlittre is reliable, patients improve their performance when performing the second test probably because they underestimate their functional capacity. These results should encourage professionals to assess TGlittre twice when using this test as an outcome measure.

Reproducibility of the 6-Min Step Test in Subjects With COPD.

BACKGROUND: Test-retest reproducibility of the 6-min step test (6MST) is controversial in patients with COPD because the decision to perform a second test is influenced by interruptions, physiological overload, and the patient's exercise tolerance. The aim of this study was to analyze the reproducibility of performance on the 6MST (ie, number of steps climbed and interruptions) and physiological variables in subjects with COPD, with and without poor exercise tolerance, and with and without interruptions during the test. METHODS: Subjects performed 2 6MST (6MST1, 6MST2) with a minimum of 30 min rest between tests. Physiological variables were assessed with a gas analyzer. Subjects who performed ≤ 78 steps in the 6MST1 and ≤ 86 steps in the test with the higher number of steps performed (6MSTBEST) were considered to have poor exercise tolerance. Subjects were also stratified according to those who interrupted the 6MSTBEST and those who did not interrupt the 6MSTBEST. RESULTS: 40 subjects (31 men; FEV1 percent of predicted = 50.4 ± 13.5) participated in the study. The number of steps, interruptions, and physiological variables showed moderate to high reliability (intraclass correlation coefficient: 0.70-0.99, P < .001). Thirty-one (77.5%) subjects had a better performance during 6MST2 than 6MST1 (mean difference: 4.65 ± 5.59, P < .001). Although the number of times subjects were interrupted was similar between the 2 tests (P = .66), the duration of these interruptions was shorter during 6MST2 (mean difference: -0.12 ± 0.39 s, P = .040). The difference in the number of steps (6MST2 - 6MST1) did not differ between subjects who performed ≤78 steps (mean difference: 5.64 ± 5.32 steps; 10.3%; P < 0.001) and ≥ 79 steps (3.00 ± 5.82 steps; 6.13%; P = 0.08) on the 6MST1 (P = 0.15) and between subjects who performed ≤ 86 steps (5.39 ± 5.14 steps; 9.39%; P < 0.001) and ≥ 87 steps (2.92 ± 6.43 steps; 2.74%; P = 0.14) steps on the 6MSTBEST (P = 0.20). CONCLUSIONS: Performance and physiological variables in the 6MST were reproducible, and a second test did not impose greater physiological overload. Two tests were essential for patients with poor exercise tolerance.

Performance difference on the six-minute walk test on tracks of 20 and 30 meters for patients with chronic obstructive pulmonary disease: validity and reliability.

BACKGROUND: Functional capacity assessment is important in patients with chronic obstructive pulmonary disease (COPD). It can be performed by the six-minute walk test (6MWT) on a 30-meter track. However, such space is not always available in clinical settings. OBJECTIVES: To compare the performance between the 6MWT on a 30- (6MWT30) and 20-meter (6MWT20) track; to evaluate the validity and reliability of the 6MWT30 and the 6MWT20; and to determine for which patients track length has the greatest impact on performance. METHODS: Patients with COPD randomly performed two 6MWT30 and two 6MWT20 on two different days and were also assessed using the COPD Assessment Test (CAT) and modified Medical Research Council (mMRC) scale. RESULTS: Thirty patients (23 men; mean ±â€¯standard deviation FEV1%pred: 45.6 ±â€¯12.1) participated in the study. They walked a greater distance on the 6MWT30 than on the 6MWT20 [mean difference: 22.1 m (95% CI: 12, 32 m)]. The longer the 6MWT30 distance, the greater the difference between the 2 tests (r = 0.51; p = 0.004). The 6MWT20 showed high reliability [ICC: 0.96 (95% CI: 0.77, 0.99)] and the results were associated with the distance walked on the 6MWT30 (r = 0.86), CAT (r = -0.53), and mMRC (r = -0.62). Patients who walked ≥430 m in the 6MWT30 presented a difference between the tests greater than those who walked <430 m (34.5 ±â€¯23.3 m vs. 12.6 ±â€¯24.1 m; respectively; p = 0.01). CONCLUSIONS: Performance was higher on the 6MWT30, with the difference increasing as performance improved. Therefore, the 6MWT20 is valid and reliable to evaluate functional capacity but should not be considered interchangeable with the 6MWT30, especially for the less disabled patients with COPD.

The minimal important difference for Glittre-ADL test in patients with chronic obstructive pulmonary disease.

OBJECTIVE: To determine Glittre-ADL test minimal important difference in patients with chronic obstructive pulmonary disease. METHODS: This is quasi-experimental study. Sixty patients with moderate to very severe chronic obstructive pulmonary disease (age 64.1, SD=9.09 years; forced expiratory volume in the first second 37.9, SD=13.0% predicted participated in a pulmonary rehabilitation program based on physical training, conducted over 24 sessions supervised, three times a week, including aerobic training in treadmill and resistance training for upper limbs and lower limbs. The main outcomes were the Glittre-ADL test and six-minute walk test, before and after 24 sessions of pulmonary rehabilitation. The minimal important difference was established using the distribution and anchor-based methods. RESULTS: Patients improved their functional capacity after the pulmonary rehabilitation. The effect sizes of Glittre-ADL test and six-minute walk test improvement were similar (0.45 vs 0.44, respectively). The established minimal important differences ranged from -0.38 to -1.05. The reduction of 0.38min (23s) corresponded to a sensitivity of 64% and a specificity of 69% with an area under the curve of 0.66 (95%CI 0.51-0.81; p=0.04). Subjects who achieved the minimal important difference of -0.38min for the Glittre-ADL test had a superior improvement of approximately 42m in the six-minute walk test when compared to patients who did not. CONCLUSIONS: The present findings suggest -0.38min as the minimal important difference in the time spent in the Glittre-ADL test after 24 sessions of pulmonary rehabilitation in patients with chronic obstructive pulmonary disease. TRIAL REGISTRATION: NCT03251781 (https://clinicaltrials.gov/ct2/show/NCT03251781).

The London Chest Activity of Daily Living scale cut-off point to discriminate functional status in patients with chronic obstructive pulmonary disease.

OBJECTIVE: To determine the cut-off point for the London Chest Activity of Daily Living scale in order to better discriminate functional status. Secondarily, to determine which of the scores (total or %total) is better associated with clinical outcomes of a pulmonary rehabilitation program. METHODS: Sixty-one patients with chronic obstructive pulmonary disease performed the following tests: spirometry; Chronic Obstructive Pulmonary Disease Assessment Test; Saint George's Respiratory Questionnaire; modified Medical Research Council, the body-mass index, airflow obstruction, dyspnea, and exercise capacity index; six-minute walk test; physical activity in daily life assessment and London Chest Activity of Daily Living scale. Thirty-eight patients were evaluated pre- and post-pulmonary rehabilitation . The cut-off point was determined using the receiver operating characteristic curve with six-minute walk test (cut-off point: 82%pred), modified Medical Research Council (cut-off point: 2), level of physical (in)activity (cut-off point: 80min per day in physical activity ≥3 metabolic equivalent of task) and presence/absence of severe physical inactivity (cut-off point: 4580 steps per day) as anchors. RESULTS: A cut-off point found for all anchors was 28%: modified Medical Research Council [sensitivity=83%; specificity=72%; area under the curve=0.80]; level of physical (in)activity [sensitivity=65%; specificity=59%; area under the curve=0.67] and classification of severe physical inactivity [sensitivity=70%; specificity=62%; area under the curve=0.70]. The patients who scored ≤28% in %total score of London Chest Activity of Daily Living had lower modified Medical Research Council , Chronic Obstructive Pulmonary Disease Assessment Test, Saint George's Respiratory Questionnaire, body-mass index, airflow obstruction, dyspnea and exercise capacity index and sitting time than who scored >28%, and higher forced expiratory volume in the first second, time in physical activity ≥3 metabolic equivalent of task, steps per day and six-minute walk distance. The %total score of London Chest Activity of Daily Living correlated better with clinical outcomes than the total score. CONCLUSIONS: The cut-off point of 28% is sensitive and specific to distinguish the functional status in patients with chronic obstructive pulmonary disease. The %total score of the London Chest Activity of Daily Living reflects better outcomes of chronic obstructive pulmonary disease when compared to total score.

Baseline characteristics associated to improvement of patients with COPD in physical activity in daily life level after pulmonary rehabilitation.

BACKGROUND: Knowing the patients with chronic obstructive pulmonary disease (COPD) that increase the physical activity of daily living (PADL) after pulmonary rehabilitation (PR) is a challenge. AIMS: to compare baseline characteristics between patients who achieved and failed to achieve the minimal important difference (MID) of PADL post-PR; to verify which baseline variables better predict the change and identify a cut-off point to discriminate MID achievers. METHODS: Fifty-three patients with COPD (FEV1: 38.3; 95%CI 34.4-42.2%pred) were evaluated for spirometry, dyspnea, quality of life, functional capacity, mortality risk and PADL level. After 24 sessions of PR had their PADL level revaluated. RESULTS: The MID achievers presented lower FEV1, functional capacity, time walking, number of steps, active time, energy expenditure (EE) walking, time on PADL≥3 metabolic equivalent of task (METs) and higher time on PADL<1.5MET. Inactive patients and with severe physical inactivity presented a hazard ratio of 4.27 and 6.90 (95%CI: 1.31-13.9, p = 0.02; 95%CI: 1.99-23.9, p = 0.002; respectively) for achieving the MID. The variables of predictive model for the change in the PADL were EE walking and time on PADL<1.5MET (R2: 0.37; p = 0.002). The cut-off point of 6525 steps [sensitivity = 95%; specificity = 61%; AUC = 0.82 (95%CI: 0.71-0.93), p < 0.001] was able to discriminate patients who achieved and failed to achieve the MID. CONCLUSION: Patients with worse lung function, functional capacity and lower PADL level before PR are those that improve the PADL level. EE walking and time on PADL<1.5MET better predict this change. The cut-off point of 6525 steps can help to identify patients with higher chances of improving the PADL level.