Utilities Estimated from PROMIS Scales for Cost-Effectiveness Analyses in Stroke

Abstract

Background

The EQ-5D and Health Utilities Index Mark 3 (HUI-3) are preference-based measures used in cost-effectiveness studies. The Patient Reported Outcomes Measurement Information System (PROMIS) Preference scoring system (PROPr) is a new preference-based measure. In addition, algorithms were previously developed to map PROMIS Global Health (PROMIS-GH) items to HUI-3 using linear equating (HUI_LE) and 3-level EQ-5D using linear (EQ5D_LE). We sought to evaluate and compare estimated utilities based on PROPr and PROMIS-GH in adult stroke survivors.

Methods

We performed a retrospective cohort study of adults diagnosed with 1 of ischemic stroke, intracerebral hemorrhage, or subarachnoid hemorrhage seen in an outpatient clinic between 2015 and 2019. Patients completed PROMIS scales and other measures. We computed a modified version of PROPr (mPROPr) and compared the distributional characteristics and correlations with stroke outcomes for mPROPr, HUI_LE, and EQ5D_LE.

Results

T toal of 4,159 stroke survivors (average age 62.7 ± 14.7 y, 48.4% female, 77.6% ischemic stroke) were included. Mean utility estimates for mPROPr, EQ5D_LE, and HUI_LE were 0.333 ± 0.244, 0.739 ± 0.201, and 0.544 ± 0.301, respectively. Correlations between the modified Rankin Scale and each of mPROPr and HUI_LE were both −0.48 and −0.43 for EQ5D_LE. Regression analyses indicated that mPROPr scores may be too low for stroke patients in good health and that EQ5D_LE scores may be too high for stroke patients in poor health.

Conclusions

All 3 PROMIS-based utilities were associated with measures of stroke disability and severity, but the distributions of utilities were very different. Our study highlights the problem cost-effectiveness researchers face of valuing health states with certainty. For researchers using utilities estimated from PROMIS scales, our study indicates that mapping PROMIS-GH item scores to HUI-3 via linear equating may be most appropriate in stroke patients.

Highlights

• A new preference-based measure has been developed from the Patient Reported Outcomes Measurement Information System (PROMIS), known as the PROMIS-Preference (PROPr) scoring system, and published equations mapping PROMIS Global Health (PROMIS-GH) items to the Health Utilities Index Mark 3 (HUI-3) and EQ-5D-3L are available for use in cost-effectiveness studies.

• Our study provides distributional characteristics and comparisons of utilities estimated using a modified version of PROPr and equations mapping PROMIS-GH items to EQ-5D-3L and HUI-3 in a sample of stroke survivors.

• The results of our study show large differences in the distributions of utilities estimated using the different health state measures, and these differences highlight the ongoing difficulty researchers face in valuing health states with certainty.