A field test of functional status as performance of activities of daily living in COPD patients.

Patients with chronic obstructive pulmonary disease (COPD) frequently experience activity restrictions and discomfort during activities of daily living (ADL). Functional status refers to the capacity to perform ADL. Available tests only partly measure this domain. Our aim was therefore to establish an assessment tool for functional status in COPD, the Glittre ADL-test. This field test includes a standardised set of ADL-like activities: Walking stairs, carrying, lifting objects, bending down and rising from a seated position. The primary variable was time to complete the test (ADL-time). Validity was investigated in 57 COPD patients by correlating ADL-time to pulmonary function, 6-min walking distance (6MWD) and questionnaires addressing health-related quality of life. Responsiveness was investigated in another 40 patients comparing ADL-time before and after rehabilitation. Median ADL-time was 4.16 min (range 2.57-14.47). Spearman rho=0.93 for test-retest reliability. ADL-time correlated with forced expiratory volume in 1s (rho=-0.61), St. George's Respiratory Questionnaire activity subscore (rho=0.43), dyspnoea during ADL (rho=0.35) and hospitalisation rate (rho=0.35). Despite a close overall correlation with 6MWD (rho=-0.82), variability was substantial, particularly for the more disabled patients. ADL-time improved significantly after rehabilitation. Glittre ADL-test yields information complementary to 6MWD. It is a valid and reliable measure of functional status, useful for assessment of individual patients and rehabilitation programs.