New study design evaluated the validity of measures to assess change after hip or knee arthroplasty

OBJECTIVE: We propose a study design to evaluate the ability of measures to assess physical function relatively independent of pain. We illustrate the design using data from patients scheduled for total hip (THA) or knee (TKA) arthroplasty. STUDY DESIGN AND SETTING: A repeated-measure study design was developed and applied to patients undergoing THA or TKA. A performance battery (PB) (walking, stair, and timed-up-and-go) was used as the gold …