Background:
A transition to value-based care requires a thorough understanding of the costs and impacts of various interventions on patients’ overall health utility. The Patient-Reported Outcomes Measurement Information System (PROMIS) has gained popularity and is frequently used to assess physical, mental, and social health domains in clinical and research settings. To assess health utility, the PROMIS-Preference (PROPr) score, a societal preference-based measure, has been proposed to produce a single estimate of health utility. We determined the psychometric properties (validity and responsiveness) of the PROPr score as a health state utility measure in patients undergoing spine surgery. We hypothesized that PROPr score would be lower in the presence of comorbid conditions and lower socioeconomic status and in those with more severe pain-related disability and would be responsive to changes in health status following spine surgery.
Methods:
In this prospective cohort study, 904 adults presented for cervical (n = 359) and/or lumbar (n = 622) conditions, and 624 underwent surgery, from August 2019 through January 2022. To assess concurrent validity, we correlated the PROPr score with Neck Disability Index (NDI)/Oswestry Disability Index (ODI) values. To assess known-groups validity, we regressed the PROPr score on participant age, sex, pain-related disability, and social determinants of health. To assess responsiveness, we used an anchor-based approach, evaluating change from preoperatively to 6 and 12 months postoperatively anchored by the Patient Global Impression of Change. A p level of <0.05 was considered significant.
Results:
The median overall preoperative PROPr score was 0.20 (interquartile range [IQR], 0.10 to 0.32; range, –0.02 to 0.95). The PROPr score was associated with higher educational attainment (p = 0.01), higher household income (p < 0.001), and a greater number of comorbid conditions (p = 0.04). The median PROPr score decreased (worse health utility) with greater disability (NDI, 0.44 [none] to 0.09 [severe/complete], p < 0.001; ODI, 0.57 [none] to 0.08 [severe/complete], p < 0.001). The change in the median PROPr score differed in participants who rated their postoperative health as improved (0.17) compared with little or no change (0.04; p < 0.001) or worse (–0.06; p = 0.025) at 6 months and in those who rated their health as improved (0.15) compared with little or no change (0.02; p < 0.001) or worse (–0.05; p = 0.043) at 12 months.
Conclusions:
The PROPr score is a valid and responsive preference-based assessment of health utility for patients undergoing spine surgery. It can be calculated from PROMIS outcome data.
Level of Evidence:
Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.