Measurement Properties of Short Lower Extremity Functional Exercise Tests in People With Chronic Obstructive Pulmonary Disease: Systematic Review

Background: An increasing variety of short functional exercise tests are reported in people with chronic obstructive pulmonary disease (COPD). Systematic review of the psychometric properties of these exercise tests is indicated. Purpose: The aim of this study was to determine the reliability, validity, and responsiveness of short (duration < 6 min) lower extremity functional exercise tests in people with COPD. Data Sources: Five databases were searched: MEDLINE, Embase, Scopus, AMED, and CINAHL. Study Selection: Studies reporting psychometric properties of short functional exercise tests in people with COPD were included. Data Extraction: Two reviewers independently extracted data and rated the quality of each measurement property using the COnsensus-based Standards for the Selection of Health Measurement INstrument (COSMIN). Data Synthesis: Twenty-nine studies were identified reporting properties of 11 different tests. Four-meter gait speed [4MGS] and 5 repetition sit-to-stand [5STS] demonstrated high reliability (ICC = .95-.99; .97) with no learning effect (COSMIN study ratings = good--excellent). Their validity for use as a stratification tool anchored against an established prognostic indicator (area under receiver operator characteristics curve [AUC] = 0.72-0.87; 0.82) and responsiveness to change after pulmonary rehabilitation was greatest in more frail people with COPD. Studies of the Timed "Up and Go" [TUG] test support use of a practice test and show discriminative ability to detect falls history and low six-minute walk distance (AUC = 0.77; 0.82, COSMIN ratings = fair-excellent). Limitations: Earlier studies were limited by small sample size. Limited data of lower study quality was identified for step tests and the Two-Minute Walk Test. Conclusions: Selected short functional exercise tests can complement established exercise capacity measures, in stratification and measuring responsiveness to change especially in people with COPD and lower functional ability.