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

Abstract

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.