Cost-utility analysis of total hip arthroplasties. Technology assessment of surgical procedures by mailed questionnaires.

A retrospective study comparing 700 consecutive total hip arthroplasties, utilizing four types of implants, was performed. Questionnaires based on hip scores were sent to 593 living patients. Useful responses were received from 363 (61%) patients. Hip scores and quality-adjusted life-years were calculated. Multiple regression analysis, controlling for all possible biases, demonstrated one cementless implant as superior to all others. We believe that the use of mailed questionnaires is a simple and convenient system of follow-up, saving patients the need for outpatient clinic visits. The validity of such replies, however, has yet to be established.