Association Between Medicaid Prescription Drug Caps And Antiretroviral Adherence Among People Living With HIV.

To control spending, some state Medicaid agencies "cap" the number of prescriptions that a beneficiary can fill each month, presenting a potential barrier to medication adherence for people with chronic health conditions. To evaluate the association between Medicaid prescription drug cap policies and antiretroviral therapy (ART) adherence among people living with HIV, we compared beneficiaries in four states with caps to beneficiaries in eight states without caps during the period 2016-19. In three of four cap states, cap status was associated with a 9 percent relative reduction in the percentage of days covered by ART over the course of twelve months compared to noncap states, and a 24 percent relative reduction in the likelihood of achieving optimal ART adherence (90 percent or higher) over the course of twelve months. The association was stronger for people with higher baseline ART adherence or more baseline comorbidities. We also identified racial and ethnic disparities, where the magnitude of ART adherence reduction associated with caps was significantly greater for Black and Hispanic people than for White people. Medicaid prescription drug cap policies appear to be both a potential source of racial and ethnic disparity and an impediment to achieving clinical targets for optimal ART adherence among people with HIV.