Psychometric evidence for outcome measures used in patients undergoing total knee arthroplasty: a systematic review

Article type
Authors
Gagnier J1, Huang W1, Mullins M1
1University of Michigan, USA
Abstract
Introduction: Total knee arthroplasty (TKA) is a viable treatment option for improving pain and function due to severe osteoarthritis. Current recommendations suggest using patient reported outcome (PRO) data to assess TKA outcomes. Many PRO instruments have been developed and compared, but this research often has questionable quality and does not adhere to methodologic and reporting guidance.
Objectives: 1) to identify currently available PRO questionnaires used in TKA patients; 2) to assess the risk of bias of studies that evaluate psychometric properties of identified instruments; 3) to assess the psychometric evidence of these instruments; and 4) to provide a summary of the overall evidence across each PRO measure.
Methods: We searched MEDLINE, EMBASE, CINAHL, SportDiscus, the Cochrane Library, Scopus (1931 to 2014), reviewed reference lists and contacted experts to identify relevant articles. We included articles on the development or evaluation of a psychometric property of a PRO measure in those undergoing TKA and published in English. The study risk of bias was appraised using the 'consensus-based standards for the selection of health status measurement instruments' checklist and psychometric evidence assessed using criteria proposed by Terwee et al. Finally, we combined these assessments to arrive at a synthesis of overall evidence for each PRO measure.
Results: We included a total of 59 studies on 15 different PRO instruments, with Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index and the Oxford Knee Score (OKS) being the most frequent. Most instruments had poor evidence, and only the OKS and the Osteoarthritis Knee and Hip Quality of Life questionnaire (OAKHQOL) had any excellent evidence. OAKHQOL had the highest overall performance with three properties having positive evidence.
Conclusions: Despite many studies on PRO instruments for TKA, few are of good quality. As a whole, additional studies are needed throughout the literature to produce quality evaluations of PRO instruments for TKA. We recommend that reporting and methodologic guidelines be developed for the assessment of psychometric properties of PRO measures.