WOMAC Physical Function Scores Research Articles

Validation of the Western Ontario and McMaster University Osteoarthritis Index in Asians with Osteoarthritis in Singapore

Objective To assess the reliability and validity of the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) as an outcome measure in Asian patients with knee or hip osteoarthritis (OA) in Singapore.Design The WOMAC was administered twice 7 days apart to 66 consecutive English-speaking Chinese, Malay or Indian inpatients and outpatients with knee or hip OA seen at a tertiary referral centre through a structured interview, which also assessed demographic and other characteristics. Internal consistency was assessed using Cronbach's alpha, reliability using Spearman's correlations, intraclass correlations and repeatability coefficients, and relationships between WOMAC domains and known determinants of function using Spearman's correlations and the Mann–Whitney U-test.Results The WOMAC showed good internal consistency (α=0.70 to 0.93) and good reliability, with intraclass correlations of 0.83 to 0.90 and mean test–retest score differences of 0.02 to 0.13 points (possible range 4 points). Results of Likert scoring assessment supported the validity of the WOMAC when interpreted in the context of the close association between pain and physical function. Eight of nine a priori hypotheses relating WOMAC Pain and Physical Function scores to known determinants of function were present, supporting construct validity of this scale.Conclusion The WOMAC is a valid and reliable outcome measure in Asian patients with OA in Singapore.

Correlation of measured range of hip motion following total hip arthroplasty and responses to a questionnaire

Twenty-eight patients (with 30 primary and 8 revision total hip arthroplasties) completed a standardized questionnaire containing the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index and Harris hip score questions prior to an office visit a minimum of 1 year after surgery. The range of hip motion measured by an orthopaedic surgeon was compared with the responses to questions on stiffness and function as well as with global scores in the WOMAC osteoarthritis index. Patient responses to the questions asking if they could cut their toenails on the operated side and the Harris hip score question asking if they could put on socks and tie a shoe correlated significantly with postoperative hip motion ( P < .005). The WOMAC global pain and stiffness scores did not correlate with range of motion. The WOMAC physical function score correlated significantly only with hip flexion ( P < .05). Of the WOMAC physical function questions, difficulty bending to pick an object off the floor ( P < .05) and getting on and off the toilet ( P < .05) correlated with the sum of the range of motion in all planes and weighted Harris hip score range of motion calculation. These data suggest that the points allocated in the Harris hip score for range of motion can be estimated reasonably accurately from questionnaire or phone response to a series of questions on a standardized questionnaire. The question on ability to cut toenails or the Harris hip score question regarding ability to put on socks and tie a shoe correlated with the most individual planes of motion, but several WOMAC physical function questions also correlated with total and weighted range of motion calculations.