Is the Harris hip score system useful to study the outcome of total hip replacement?

Although the Harris hip score frequently is used to assess the outcome of total hip replacement, only a few minor validity tests have been presented. The aim of this study was to perform a validity test of the Harris hip score and to test its reliability. Two cohorts were studied. First, 58 patients who had undergone total hip replacement 2 to 10 years earlier were evaluated by an orthopaedic surgeon and an experienced physiotherapist using the Harris hip score. The patients also answered the Western Ontario and McMaster University Osteoarthritis Index and the Medical Outcomes Study 36-Item Short-Form Health Survey. Second, 1,056 patients answered the Western Ontario and McMaster University Osteoarthritis Index and the Medical Outcomes Study 36-Item Short-Form Health Survey questionnaires. The results were compared with those of a subcohort of 344 patients who were evaluated using the Harris hip score. The following items were tested: content validity, convergent and divergent construct validity, criterion validity, test and retest reliability, internal consistency reliability, and interobserver reliability. The Medical Outcomes Study 36-Item Short-Form Health Survey, Western Ontario and McMaster University Osteoarthritis Index, and the Harris hip score showed high validity and reliability. The Harris hip score can be used by a physician or a physiotherapist to study the clinical outcome of hip replacement.