Assessing performance-related disability in patients with knee osteoarthritis

Abstract

This investigation describes the development and validation of a test battery for evaluating physical activity restrictions (PAR) in patients with knee osteoarthritis (OA). The tasks on the final version of the PAR include (a) a 6-min walk; (b) a stair climb; (c) a lifting and carrying task; and (d) getting into and out of a car. Data from patients with knee OA revealed that the four tasks loaded highly on a single unrotated principal component yielding an alpha internal consistency reliability of 0.92. These data suggest that investigators may choose to use an aggregate score and/or responses from individual tasks. Two week test-retest reliabilities for the four tasks were all in excess of 0.85 and there was support for their concurrent and convergent validity. Specifically, performance on the tasks correlated with time on treadmill, difficulty with self-reported ADLs, and ratings of difficulty following the performance of each task. Additional research is needed on the predictive validity of the measure and its sensitivity to change.

Preoperative predictors of locomotor ability two months after total knee arthroplasty for severe osteoarthritis

“…Construct and concurrent validity of the 6-minute gait test has been extensively demonstrated in populations with cardiopulmonary problems (41,44 -51). In populations with OA, a good concurrent validity was also shown with respiratory measures (52,53), knee extensor strength (53), stride characteristics (44), and timed up and go (54). Moreover, the predictive ability of the 6-minute gait test was studied.…”

“…A poor locomotor ability was predictive of: morbidity-mortality in persons with left ventricular dysfunction (46,48), the need for transplantation in persons with end stage pulmonary disease (55), and poorer surgical results after pulmonary resection (56). A good test-retest reliability was found even without any familiarization trials in different populations (42,46,49,53). With respect to responsiveness, the 6-minute gait test was found to be the most responsive locomotor test among those tested with persons operated for TKA (57,58).…”

Long‐Term Exercise Therapy Resolves Ethnic Differences in Baseline Health Status in Older Adults with Knee Osteoarthritis

“…The validity and reliability of this test has been established for individuals with mobility disability. 27 Participants were asked to walk as far as they could in 6 minutes Each participant began walking at the command ''go'' and continued walking until he or she heard the command ''stop.'' Participants were not given any performance feedback during the trial.…”

Economic evaluation of multidisciplinary rehabilitation after primary total knee arthroplasty based on a randomized controlled trial

“…To score the function scale, we calculated the mean of the item scores (22). The secondary outcome measures were: the WOMAC subscale score for function at the 2-and 6-month followup periods; at all followup periods the 15D score, which is a generic, 15-dimensional, standardized, self-administered instrument that measures HRQOL and that can be used both as a profile and a single-index score measure (the maximum score is 1 [no problems in any dimension] and the minimum score is 0 [equal to being dead] [23]); the WOMAC composite score and subscale scores of pain and stiffness (22); and the results of objectively measured physical performance, based on a 15-meter walk test (24), a stair test (25), and isometric strength of the knee (26), measured with the Lido Active Multijoint Rehabilitation System (Loredan Biomedical).…”