Paul W. Stratford, Deborah M. Kennedy and Daniel L. Riddle
This article proposes a study design to evaluate the ability of measures to assess physical function relatively independent of pain for total hip (THA) or knee (TKA) arthroplasty. 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 standard measure for â€œphysical function.â€ Recent evidence indicates physical performance deteriorates 1 month after surgery compared to presurgical measures and patients with THA deteriorate to a greater extent than patients with TKA. Our design assessed whether the results from self-report measures (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] and the Lower Extremity Functional Scale [LEFS]) of physical function were consistent with changes found using the PB.
Our findings support the proposed design in that the PB was more sensitive to change than the self-report measures.
Journal of Clinical Epidemiology, 2009, 62(3), 347-352