A comparison of SF-6D and EQ-5D utility scores in a study of patients with schizophrenia

Economic evaluations of healthcare interventions increasingly measure outcomes using quality-adjusted life years (QALYs). The SF-6D and the EQ-5D are alternative ways of generating utility scores for use in QALY estimations. This study compares these measures in a sample of patients with schizophrenia. Mean utility scores were very similar at baseline (EQ-5D 0.68, SF-6D 0.67) and follow-up (EQ-5D 0.71, SF-6D 0.68). The SF-6D scores followed a normal distribution whilst the EQ-5D scores were negatively skewed with a clustering at 1.00. There were few differences in sensitivity to change between the EQ-5D and SF-6D. From an analytical perspective the SF-6D has advantages over the EQ-5D due to its normal distribution and lack of ceiling effect. However, both measures produce similar mean utility scores. Overall the SF-6D appears more suitable as a measure if utility in this patient group.