Rates of antiretroviral therapy (ART) prescription and sustained viral suppression rose in young U.S. adults from 2009 through 2013, according to analysis of a nationally representative sample in the Medical Monitoring Project (MMP). But, by 2013, fewer than two-thirds of young adults had attained viral suppression on their last test.
Prior study of all adults in the MMP determined that the ART prescription rate rose from 89% in 2009 to 94% in 2013. Over those same years, the proportion of people with an undetectable viral load on their last measure climbed from 72% to 80%. But a 2011 MMP study calculated that only 13% of young adults with HIV achieve viral suppression, and young adults are less likely than older adults to take ART, adhere to ART or reach an undetectable viral load. However, a 2002-2010 study in another U.S. cohort charted rising ART use and falling viremia in youth.
Centers for Disease Control and Prevention (CDC) researchers conducted the new study to estimate changes in prevalence of ART prescription, adherence, side effects, single-tablet regimens, regular care utilization and viral suppression among 18- to 24-year-olds receiving HIV care in the United States or Puerto Rico. Participants came from the MMP, a cohort designed to yield annual nationally representative samples of U.S. adults in care for HIV infection. The CDC team collected interview and medical record abstraction data from June 2009 through May 2014. They weighted data based on known probabilities of participant selection at state, facility and patient levels. They used bivariate regression analysis to determine weighted percentages by year for each outcome. The investigators used multivariate linear regression to determine the impact of other significant covariates on viral suppression rates over time.
Of the 636 young-adult participants, 43% were black men, 62% were men who have sex with men, 62% lived in a household below the poverty level and 35% had no health insurance or only Ryan White Program coverage. The proportion of participants prescribed ART rose significantly from 76% in 2009 to 87% in 2013 (P = .01). Among people with an ART prescription, the proportion taking a single-tablet regimen climbed from 49% in 2009 to 62% in 2013 (P = .04). But adherence and side effects rates did not change significantly over the study period. Nor did regular care utilization change significantly in these young adults.
Suppression rate at the last viral load test stood at 65% in both 2009 and 2013. But the proportion of participants with sustained viral suppression (< 200 copies/mL on all tests in the past 12 months) rose from 29% in 2009 to 46% in 2013, P ≤ .01). Multivariate regression identified two factors that attenuated the sustained viral suppression trend: having an ART prescription (P = .02) and using a single-tablet regimens (P = .04). These findings suggest that increasing ART prescriptions and increasing single-tablet regimen use account for some of the improvement in sustained viral suppression.
The CDC researchers stress that the flat 65% suppression rate at the last test falls far short of the 80% goal set in the National HIV/AIDS Strategy. But, they believe the rising sustained suppression rate indicates some progress in HIV care for "this disproportionately affected population" of young adults. The authors speculate that HIV providers may have become less concerned about poor adherence as a reason for delaying ART in young adults "because of increasing evidence of the benefits of early ART and the availability of better regimen options that are more forgiving of nonadherence."