The test-retest reliability of four functional mobility tests in apparently healthy adults

BACKGROUND: Simple field tests are often used to assess functional mobility in clinical settings. Despite having many benefits, these tests are susceptible to measurement error and individual variation. OBJECTIVES: To examine the test-retest and absolute reliability of the timed up and go test (TUG), five times sit-to-stand (FTSTS), stair climb test (SCT) and 6 minute walk test (6MWT). METHODS: Over two sessions, thirty-five subjects (30-74 years), repeated the four tests approximately four weeks apart. Test-retest reliability (intraclass correlations [ICC]) and absolute reliability (95% limits of agreement [95% LOA]; standard error of measurement [SEM] and minimum detectable change [MDC]) were calculated. RESULTS: All four tests had high test-retest reliability (ICC > 0.95) although significant between session changes were present for the TUG and FTSTS (p < 0.05). FTSTS displayed the greatest measurement error whilst 95% LOA was the most conservative measure of absolute reliability. CONCLUSIONS: The results of this study indicate that the TUG, FTSTS, SCT and 6MWT are reliable when performed four weeks apart. Furthermore, the inclusion of SEM, MDC and 95% LOA provides reference values to aid in identifying changes over time above those of measurement error and individual variation.