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 30meter track. However, such space is not always available in clinical settings. Objectives: To compare the performance between the 6MWT on a 30-(6MWT 30 ) and 20-meter (6MWT 20 ) track; to evaluate the validity and reliability of the 6MWT 30 and the 6MWT 20 ; and to determine for which patients track length has the greatest impact on performance. Methods: Patients with COPD randomly performed two 6MWT 30 and two 6MWT 20 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 ± standard deviation FEV 1 %pred: 45.6 ± 12.1) participated in the study. They walked a greater distance on the 6MWT 30 than on the 6MWT 20 [mean difference: 22.1 m (95% CI: 12, 32 m)]. The longer the 6MWT 30 distance, the greater the difference between the 2 tests (r = 0.51; p = 0.004). The 6MWT 20 showed high reliability [ICC: 0.96 (95% CI: 0.77, 0.99)] and the results were associated with the distance walked on the 6MWT 30 (r = 0.86), CAT (r = −0.53), and mMRC (r = −0.62). Patients who walked ≥430 m in the 6MWT 30 presented a difference between the tests greater than those who walked <430 m (34.5 ± 23.3 m vs. 12.6 ± 24.1 m; respectively; p = 0.01).
The study objective was to determine a cut-off point for the Glittre activities of daily living (ADL)test (TGlittre) to discriminate patients with normal and abnormal functional capacity. Fifty-nine patients with moderate to very severe COPD (45 males; 65 ± 8.84 years; BMI: 26 ± 4.78 kg/m; FEV: 35.3 ± 13.4% pred) were evaluated for spirometry, TGlittre, 6-minute walk test (6 MWT), physical ADL, modified Medical Research Council scale (mMRC), BODE index, Saint George's Respiratory Questionnaire (SGRQ), and COPD Assessment Test (CAT). The receiver operating characteristic (ROC) curve was used to determine the cut-off point for TGlittre in order to discriminate patients with 6 MWT < 82% pred. The ROC curve indicated a cut-off point of 3.5 minutes for the TGlittre (sensitivity = 92%, specificity = 83%, and area under the ROC curve = 0.95 [95% CI: 0.89-0.99]). Patients with abnormal functional capacity had higher mMRC (median difference 1 point), CAT (mean difference: 4.5 points), SGRQ (mean difference: 12.1 points), and BODE (1.37 points) scores, longer time of physical activity <1.5 metabolic equivalent of task (mean difference: 47.9 minutes) and in sitting position (mean difference: 59.4 minutes) and smaller number of steps (mean difference: 1,549 minutes); p < 0.05 for all. In conclusion, the cut-off point of 3.5 minutes in the TGlittre is sensitive and specific to distinguish COPD patients with abnormal and normal functional capacity.
The aim of this study was to investigate whether the chronic obstructive pulmonary disease (COPD) assessment test (CAT) reflects the functional status of patients with COPD. Forty-seven patients underwent anthropometric assessment, spirometry, the 6-minute walk test (6MWT), the Glittre-activity of daily living (ADL) test (TGlittre), the London Chest ADL (LCADL) scale, and the CAT. The total score of the CAT correlated with 6MWT distance, TGlittre time spent, and LCADL %total (r ¼ À0.56, 0.52, and 0.78, respectively; p < 0.05 for all). There was significant difference in 6MWT distance (490 + 85.4 m vs. 387 + 56.8 m), TGlittre time spent (3.67 + 1.07 min vs. 5.03 + 1.32 min), and LCADL %total (24.2 + 3.02% vs. 44.4 + 13.3%) between the low and high impacts of COPD on health status (respectively, p < 0.05 for all) as well as in the LCADL %total between medium and high impact of COPD on health status (31.3 + 7.35% vs. 44.4 + 13.3%; p ¼ 0.001). In conclusion, the CAT reflects the functional status of patients with COPD.
The TGlittre time and ventilatory parameters are reproducible, while DH is variable in COPD patients. A 6-7% learning effect was shown, and it is recommended to perform two tests.
Purpose:
To describe physiological responses during the 6-min step test (6MST) in patients with chronic obstructive pulmonary disease (COPD), to investigate whether COPD severity and test interruptions could determine different physiological responses, and to test the reproducibility of 6MST performance.
Methods:
Cross-sectional study. Patients with moderate to very severe COPD underwent lung function assessment and 2 6MSTs, with physiological responses measurement by a gas analyzer and a near-infrared spectroscopy device.
Results:
Thirty-six patients (29 men; forced expiratory volume in the first second of expiration [FEV1] = 51.1 ± 13.6%pred) participated in the study. Most of the physiological variables stabilized between the second and fourth minutes of the 6MST, except the respiratory rate and heart rate (HR), which stabilized after the fifth minute. The patients who interrupted the 6MST showed higher minute ventilation to maximal voluntary ventilation ratio (
JOURNAL/jcprh/04.03/01273116-202001000-00010/10FSM1/v/2023-09-11T232142Z/r/image-gif
e/mvv; all test minutes) and HR (first and second minutes) (P < .05) and worse pulmonary function (FEV1 = 1.37 ± 0.37 L vs 1.82 ± 0.41 L, P = .002, and 47.2 ± 13.2%pred vs 56.6 ± 12.4%pred, P = .04, respectively) than those who did not interrupt the 6MST. However, their performance was similar (P = .11). 6MST performance and physiological variables were reproducible, and there was a learning effect of 6.28%.
Conclusions:
The 6MST showed a stabilization of the most physiological variables. In addition, interruptions were usually made by patients with a greater impairment of lung function and they presented greater increased ventilatory demand during the 6MST. However, these interruptions do not interfere with 6MST physiological responses. Moreover, the 6MST is a reliable test to evaluate the functional capacity of patients with COPD.
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 (FEV 1 : 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 FEV 1 , 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 (R 2 : 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. Recently, a study demonstrate that patients with better baseline
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