Appropriate questionnaires for knee arthroplasty - Results of a survey of 3600 patients from the Swedish Knee Arthroplasty Registry

The Swedish Knee Arthroplasty Registry (SKAR) has recorded knee arthroplast ies prospectively in Sweden since 1975, The only outcome measure available to date has been revision status. While questionnaires on health outcome ma y function as more comprehensive endpoints, it is unclear which are the mos t appropriate. We tested various outcome questionnaires in order to determi ne which is the best for patients who have had knee arthroplasty as applied in a cross-sectional, discriminative, postal survey. Four general health questionnaires (NHP, SF-12, SF-36 and SIP) and three di sease/site-specific questionnaires (Lequesne, Oxford-12, and WOMAC) were te sted on 3600 patients randomly selected from the SKAR, Differences were fou nd between questionnaires in response rate, time required for completion, t he need for assistance, the efficiency of completion, the validity of the c ontent and the reliability. The mean overall ranks for each questionnaire w ere generated. The SF-12 ranked the best for the general health, and the Ox ford-12 for the disease/site-specific questionnaires. These two questionnai res could therefore be recommended as the most appropriate for use with a l arge knee arthroplasty database in a cross-sectional population.