Socioeconomic Differences in Glaucoma Medication Spending Under Medicare Part D: Evidence on Price vs Utilization

Objective To examine whether socioeconomic differences in Medicare Part D glaucoma medication spending are more strongly associated with price exposure (spending per claim) than with utilization intensity. Design Ecologic observational study using state-year–level data. Participants Medicare Part D beneficiaries receiving glaucoma medications across 50 states and the District of Columbia from 2019 through 2023 (255 state-years). Methods We analyzed Centers for Medicare 95% CI, 1. 30–35. 06) and per claim (6. 99; 95% CI, 1. 95–12. 03). Higher ADI was associated with lower spending per claim, although estimates were imprecise (–3. 69 per 10-point increase; 95% CI, –7. 51 to 0. 13). Utilization intensity varied minimally across socioeconomic strata (claims per beneficiary, 3. 8–4. 0), and neither ADI nor income was consistently associated with brand spending or claims share. Conclusions State-level socioeconomic context was associated with modest differences in glaucoma medication spending per claim, with minimal differences in utilization intensity. These findings suggest that socioeconomic variation in Medicare Part D glaucoma drug spending is more consistent with differences in price exposure than with differences in volume of use.