Validity of a short-term quality of life questionnaire in patients undergoing joint replacement: the Quality of Recovery-40.

One hundred thirty-two patients undergoing total hip or knee arthroplasty were evaluated before and after surgery with the Quality of Recovery-40 (QoR-40) and the Short Form 12 (SF-12) questionnaires seven times over a 4-month period, with the objective of comparing their psychometric properties. Physical dimensions of the QoR-40 and SF-12 were not related in the days after surgery but moderately related over the first month. Only the change in score for the physical independence dimension of the QoR-40 exceeded measurement error. Effect sizes were larger for the QoR-40 within the first month post-surgery and larger for the SF-12 past 1 month. Effect sizes were larger for the physical dimensions of both instruments compared to the psychological dimensions. Only the physical independence dimension of the QoR-40 appears useful to assess the quality of life in the first month following surgery.