HIV Viral Suppression Rates Improved From 1997 to 2015 in the United States

New research shows that viral suppression rates have nearly tripled since 1997 in people living with HIV in the United States, according to a study published in the Annals of Internal Medicine. However, gaps in viral suppression are still evident among younger people and African Americans, as indicated by the detectable viral load levels reported in these populations.

This longitudinal observational cohort study sought to evaluate viral suppression trends in people living with HIV and to identify associated factors, such as demographic and clinical characteristics. Patient data were analyzed for predictors of viral suppression, including substance use patterns, medication adherence, integrase strand transfer inhibitor use, and demographic information.

The study included 31,930 adults living with HIV recruited from 8 HIV clinics across the United States. All participants had their viral load levels measured as part of their clinical care between 1997 and 2015.

As a primary outcome, researchers determined viral suppression rates for each year by calculating viral load values. The study investigators then categorized viral load trends by various factors. Trend analysis was repeated by administering 1 random test per person per year to address potential loss to follow up.

Investigators then used a joint longitudinal and survival model to examine the associations between viral suppression, or detectable viral load levels, and demographic and clinical factors. Analyses were repeated for subgroups including patients who were naïve to antiretroviral therapy at enrollment and for the study period between 2010 and 2015, after treatment guidelines had been expanded.

Study results based on overall viral load levels showed that viral suppression increased from 32% in 1997 to 86% in 2015. In analyses adjusted for demographic and clinical characteristics, being older and integrase strand transfer inhibitor use were associated with lower odds of having a detectable viral load, whereas being black was associated with higher odds.

Specifically, being older was associated with an odds ratio (OR) of 0.76 per decade (95% CI, 0.74-0.78; P =.001); integrase strand transfer inhibitor use was associated with an OR of 0.54 (95% CI, 0.51-0.57; P =.001); and black race was associated with an OR of 1.68 (95% CI, 1.57-1.80; P =.001). Subgroup analyses and sensitivity analyses revealed patterns consistent with these findings.

A limitation of the study was only including people living with HIV who were receiving clinical care. Data from lower-resource clinical settings may have similarly limited the generalizability of the study. In addition, self-reported adherence data may have lacked sensitivity in detecting changes in adherence. Although statistical techniques were used to account for loss to follow up or unmeasured factors, possible bias may have further limited results.

Overall, the HIV viral suppression rates have improved in the United States, which is attributable in part to improved antiretroviral therapies, including integrase strand transfer inhibitor use. Future studies are needed to address the disparities among younger people and black people living with HIV, who are more likely to have a detectable viral load.

Reference                                                                                                                       

1. Nance RM, Delaney JAC, Simoni JM, et al. HIV viral suppression trends over time among HIV-infected patients receiving care in the United States, 1997 to 2015 [published online August 21, 2018]. Ann Intern Med. doi: 10.7326/M17-2242.
2. Marston HD, Dieffenbach CW, Fauci AS. Ending the HIV epidemic in the United States: closing the implementation gaps [published online August 21, 2018]. Ann Intern Med. doi: 10.7326/M18-1944.