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Published on: March 30, 2014
Medication Adherence and Health Care Use After Medicaid Prescription Cap Removal Among People with HIV: a
Fangli Geng1, Yutong Lu2, Christopher M Santostefano2
1Department of Health Services, Policy and Practice, Brown University School of Public Health, Providence, RI, USA. fangli_geng@brown.edu.
Background:
State Medicaid programs have implemented prescription caps to control pharmacy spending since the early 2000s. Prior evidence suggests that people with HIV may experience reduced antiretroviral therapy (ART) adherence under such policies, even when HIV medications are exempt. Whether removing caps improves medication use and health care utilization remains unclear.
Objective:
To evaluate the association between Medicaid prescription cap removal and changes in medication use, ART adherence, and health care utilization among adult Medicaid beneficiaries living with HIV.
Design, Participants:
We used a difference-in-differences and event-study design with propensity score matching to assess the impact of removing South Carolina's prescription cap, compared with nine control states that maintained caps during 2016-2019. The sample included adults aged 21-64 years with diagnosed HIV and continuous claims in pre- and post-policy periods. We excluded individuals who moved between states, resided in long-term care facilities, and were pregnant.
Main Measures:
The exposure is South Carolina's prescription cap removal on July 1, 2017. Outcomes included prescription fills, days' supply (overall and HIV-related), adherence measured as the proportion of days covered (PDC) by ART, inpatient admissions, outpatient Evaluation and Management visits and emergency department visits.
Key Results:
The matched sample included 1135 individuals in both South Carolina and control states. During the post-policy period, the change in PDC was 4.6 percentage points (95% CI, 2.7 to 6.6) greater in South Carolina than in control states. Effects peaked at 8.4 percentage points at 9 months after removal and were driven by individuals with baseline prescription fills below the cap. This improvement was accompanied by increases in HIV-related prescription fills and days' supply. No consistent changes were observed in health care utilization.
Conclusions:
Removal of prescription cap improved HIV-related prescription fills, days' supply, and ART adherence, while achieving optimal adherence and improvements in health outcomes and health care utilization may require additional strategies.
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