- STUDY DESIGN: Single-group repeated-measures study. OBJECTIVE: To examine the test-retest reliability of the timed up and go (TUG) test and its validity for measuring change and predicting length of stay (LOS) on an inpatient orthopaedic rehabilitation ward. BACKGROUND: The TUG test is used to measure functional mobility of persons with musculoskeletal conditions but it has not been thoroughly tested for use in an inpatient orthopaedic rehabilitation ward. METHODS AND MEASURES: The TUG test was administered to 142 patients on admission to an orthopaedic rehabilitation ward 7 to 10 days after admission and on discharge. To test reliability, 24 subjects had these tests repeated 1 day after admission, and the intraclass correlation (ICC) and standard error of measurement (SEM) were calculated. Change scores of the TUG test were evaluated against change scores in pain and function, and the rating of improvement of the patient and therapist. The standardized response mean (SRM) was also calculated. A regression analysis was performed to determine whether the admission TUG test score could predict LOS. RESULTS: The ICC of the TUG test was 0.80 and the SEM was 10.2 seconds. The change in TUG test scores correlated with the changes in pain (r = 0.21, P<.01) and function (r = -0.23, P<.01), and resulted in an SRM of 0.89 for subjects rated as improved. The admission TUG test scores accounted for only 3.4% of the variance in inpatient LOS. CONCLUSION: The TUG test is reliable and valid to assess group change of inpatients on an orthopaedic rehabilitation ward but is not a good predictor of LOS. LEVEL OF EVIDENCE: Prognosis, level 1b.