Patients Respond Similarly to Paper and Electronic Versions of the WOMAC and SF-12 Following Total Joint Arthroplasty

The purpose of this study was to determine agreement between responses on electronic and paper versions of the WOMAC and SF-12(v2) questionnaires following total hip and total knee arthroplasty. Patients completed both electronic and paper questionnaires with a one week interval in-between. The order in which they completed the two versions was randomly assigned. A total of 53 patients completed the study, with a mean age of 69 years (range 50-90 years). The intraclass correlation coefficients (ICC) were high, indicating excellent agreement (WOMAC ICC = 0.96, 95% CI 0.94-0.98), SF-12 (PCS) ICC = 0.95, 95% CI 0.92-0.97; SF-12 (MCS) ICC = 0.92, 95%CI 0.86-0.95). Online data collection may be substituted for the traditional paper method with no significant effect on the criterion validity of the questionnaires.