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.

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.