Objective: To determine the reliability, minimum detectable change (MDC), and validity of the Get Up and Go (GUG) test.
Design: Repeated-measures test-retest for reliability. Correlational study for validity.
Setting: Institutional practice.
Participants: Convenience sample of 130 people, 105 with knee osteoarthritis (OA) (80 women; mean age, 62+/-9 y) and 25 healthy controls (21 women; mean age, 57+/-8 y).
Interventions: Not applicable. Main outcome measures Western Ontario and McMaster Universities Osteoarthritis Index, the Activity of Daily Living Scale of the Knee Outcome Survey, and the 8 scales of the Medical Outcomes Study 36-Item Short-Form Health Survey.
Results: Intratester and intertester reliability was.95 (95% confidence interval [CI],.72-.98) and.98 (95% CI,.94-.99), respectively. The MDC, based on measurements by a single tester and between testers, was 1.5 and 1.2 seconds, respectively. Time to perform the GUG test was longer for persons with knee OA than it was for the controls (mean difference, 3.3s; 95% CI, 1.8-4.9). Correlations between the GUG test and measures of physical function did not differ significantly from correlations between the GUG test and measures that do not specifically evaluate physical function.
Conclusions: The GUG test is reliable and has an MDC that is adequate for clinical use. Validity of the GUG test as a single measure of physical function was not supported. Further research should include testing a battery of performance-based measures of physical function.