A SHORTER FORM HEALTH SURVEY - CAN THE SF-12 REPLICATE RESULTS FROM THE SF-36 IN LONGITUDINAL-STUDIES

Background The SF-36 is a generic health status measure which has gain ed popularity as a measure of outcome in a wide variety of patient gro ups and social surveys, However, there is a need for even shorter meas ures, which reduce respondent burden. The developers of the SF-36 have consequently suggested that a 12-item sub-set of the items may accura tely reproduce the two summary component scores which can be derived f rom the SF-36 [the Physical Component Summary Score (PCS) and Mental H ealth Component Summary Score (MCS)]. In this paper, we adopt scoring algorithms for the UK SF-36 and SF-12 summary scores to evaluate the p icture of change gained in various treatment groups. Methods The SF-36 was administered in three treatment groups (ACE inhibitors for conges tive heart failure, continuous positive airways therapy for sleep apno ea, and open vs laparoscopic surgery for inguinal hernia). Results PCS and MCS scores calculated from the SF-36 or a sub-set of 12 items (th e 'SF-12') were virtually identical, and indicated the same magnitude of ill-health and degree of change over time. Conclusion The results s uggest that where two summary scores of health status are adequate the n the SF-12 may be the instrument of choice.