OBJECTIVES : The PROMIS Preference score (PROPr) is a new health state utility (HSU) scores for Quality-adjusted life years (QALY) in cost-effectiveness analyses. It is the first HSU score using modern instruments based on Item Response Theory (IRT), claiming a more precise, comprehensive, and flexible measurement. The PROPr showed validity but different HSU measurement in the general population and rheumatological, psychosomatic, and breast cancer patients. Aim of this study is to validate the PROPr in a sample of lower back pain patients.

METHODS : We collected PROPr and EQ-5D-3L from 218 lower back pain patients before surgery at Charité University Medicine Berlin between April 2019 and November 2020. We assessed the PROPr’s validity, agreement, and ceiling and floor effects compared to the EQ-5D-3L.

RESULTS : The mean PROPr (0.20, 95%CI: 0.18; 0.22) and the mean EQ-5D-3L (0.55, 95%CI: 0.51; 0.58) showed significant difference (d = 0.35, p < 0.001) and poor agreement (ICC 0.27, 95%CI: -0.09; 0.59). The Pearson correlation coefficient was moderate (r = 0.66, 95%CI: 0.58; 0.73). Both scores showed similar discrimination across age and sex. The EQ-5D-3L was better able to discriminate groups of higher severity and the PROPr of lower severity in terms of Oswestry Disability Index (ODI), reflecting the PROPr’s high floor effect (52%) and the EQ-5D-3L’s ceiling effect (20%).

CONCLUSIONS : The PROPr measures HSU systematically lower than the EQ-5D-3L in lower back pain patients. This supports earlier results suggesting the PROPr has a different conceptualization of HSU with far-reaching consequences for QALY measurements.