Nonadherence to Any Prescribed Medication Due to Costs Among Adults With HIV Infection — United States, 2016–2017

Linda Beer, PhD; Yunfeng Tie, PhD; John Weiser, MD; R. Luke Shouse, MD

Disclosures

Morbidity and Mortality Weekly Report. 2019;68(49):1129-1133. 

In This Article

Abstract and Introduction

Introduction

The United States spends more per capita on prescription drugs than do other high-income countries.[1] In 2017, patients paid 14% of this cost out of pocket.[2] Prescription drug cost-saving strategies, including nonadherence to medications due to cost concerns, have been documented among U.S. adults[3] and can negatively affect morbidity and, in the case of persons with human immunodeficiency virus (HIV) infection, can increase transmission risk.[4,5] However, population-based data on prescription drug cost-saving strategies among U.S. persons with HIV are lacking. CDC's Medical Monitoring Project* analyzed cross-sectional, nationally representative, surveillance data on behaviors, medical care, and clinical outcomes among adults with HIV infection. During 2016–2017, 14% of persons with HIV infection used a prescription drug cost-saving strategy for any prescribed medication, and 7% had cost saving–related nonadherence. Nonadherence due to prescription drug costs was associated with reporting an unmet need for medications from the Ryan White AIDS Drug Assistance Program (ADAP), not having Medicaid coverage, and having private insurance. Persons who were nonadherent because of cost concerns were more likely to have visited an emergency department, have been hospitalized, and not be virally suppressed. Reducing barriers to ADAP and Medicaid coverage, in addition to reducing medication costs for persons with private insurance, might help to decrease nonadherence due to cost concerns and, thus contribute to improved viral suppression rates and other health outcomes among persons with HIV infection.

The Medical Monitoring Project uses a two-stage sample design: 1) states and territories and 2) persons with a diagnosis of HIV infection. Response rates were 100% (states and territories) and 40% (persons). Data were collected using face-to-face or telephone interviews and medical record abstraction during June 2016–May 2017. Data were weighted for unequal selection probabilities and nonresponse. Using data from 3,948 persons taking prescription drugs, the prevalence of prescription drug cost-saving strategies among U.S. adults with HIV with accompanying 95% confidence intervals (CIs) was estimated overall and by selected sociodemographic characteristics. Differences in clinical outcomes between those who did and did not have prescription drug cost saving–related nonadherence were also assessed. Prevalence ratios with predicted marginal means were used to evaluate significant (p<0.05) differences between groups. SAS software (version 9.4; SAS Institute) was used to conduct all analyses.

Persons taking prescription drugs were asked about their use of six cost-saving strategies over the past 12 months: 1) asking a doctor for a lower-cost medication, 2) buying prescription drugs from another country, 3) using alternative therapies, 4) skipping doses, 5) taking less medicine, and 6) delaying filling a prescription because of cost. Interviewees were asked about all prescription drugs, not solely antiretroviral medications. Cost saving–related nonadherence was defined as using any of the latter three strategies.[3] Persons who reported needing but not receiving medications from ADAP were categorized as having an unmet need for ADAP. All examined covariates were self-reported, except viral suppression and care engagement, which were based on medical record abstraction. All were measured over the previous 12 months except where otherwise noted.

Overall, approximately 14% (95% CI = 12–15) of U.S. adults with HIV used any medication cost-saving strategy, including 7% (95% CI = 6–8) who reported cost saving–related nonadherence; among this group, 4% (95% CI = 3–5) skipped doses, 4% (95% CI = 3–5) took less medicine, and 6% (95% CI = 5–7) delayed a prescription. In addition, 9% (95% CI = 7–10) asked a doctor for lower-cost medicine, 1% (95% CI = <1–1) bought drugs from another country, and 2% (95% CI = 2–3) used alternative medicine. Cost saving–related nonadherence was not associated with age, race/ethnicity, gender, homelessness, or time since HIV diagnosis (Table 1). Household income above the poverty level was associated with nonadherence due to prescription drug costs (8% versus 5%). Nonadherence due to prescription drug costs was higher among persons with a disability (9%) than among those with no disability (5%). Among those with health insurance, cost saving–related nonadherence was more likely among persons with private insurance (8%) than among those who did not have private insurance (6%) and was less likely among those with Medicaid (5%) than among those who did not have Medicaid (8%). Persons who had an unmet need for medications from ADAP were approximately five times as likely to be nonadherent because of cost (32%) than were those who received ADAP (7%, prevalence ratio = 5).

Persons with cost saving–related nonadherence were also less likely to be virally suppressed at their last viral load test (64%) and at all tests during the past year (55%) than were those without cost saving–related nonadherence (76% and 68%, respectively) (Table 2). Nonadherence due to prescription drug costs was also associated with lower likelihood of HIV care engagement and higher numbers of emergency department visits and hospitalizations.

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