Level of adherence and HIV RNA suppression in the current era of highly active antiretroviral therapy (HAART)

Abstract

The need to achieve ≥95 % adherence to HAART for treatment effectiveness may be a barrier for universal initiation at early stages of HIV. Using longitudinal data collected from 2006 to 2011 from cohort studies of MSM (MACS) and IDUs (ALIVE study), we estimated the minimum adherence needed to achieve HIV RNA suppression (<50 copies/mL), defined as the level at which at least 80 % were virally suppressed, and the odds of suppression was not significantly different than that observed with ≥95 % adherence. In the MACS, ≥80 % suppression was observed with 80-84 % adherence and the odds ratio for suppression (vs. ≥95 % adherence) was 1.43 (0.61, 3.33). In the ALIVE study where <35 % were on newer drugs, only 71.4 % were suppressed among those who reported ≥95 % adherence. Although IDUs on older HAART regimens may need to be ≥95 % adherent, concerns related to non-adherence may be less of a barrier to initiation of modern HAART regimens.

Figure 1. Proportion reporting ≥95% adherence over time in the MACS and ALIVE study (2001-2011)

The red dashed and blue solid lines represent the trends in reporting ≥95% adherence among all persons using HAART, and those seen since 2009, respectively. The thin black line represents the best fit line for those seen since 2009. The error bars represent 95% confidence intervals (CI) for observed proportions for those seen since 2009.

Figure 2. Proportion suppressing HIV RNA (<50 copies/mL) over time among participants with <95% adherence in the MACS and ALIVE study from 2001-2011

The blue thick line represents the observed proportion suppressed, and the black thin line represents the best fit line. The error bars represent 95% CI for the observed proportions.

Figure 3. Proportion suppressing HIV RNA (<50 copies/mL) by HAART adherence category (2006-2011)

The blue thick line represents the observed proportions, and the black thin line represents the best fit line. The error bars represent 95% CI for the observed proportions. The odds ratios and 95% CI were obtained from a random-effects logistic regression model comparing the HIV RNA suppression at lower adherence levels to adherence ≥95%, and adjusting for confounders. In the MACS, confounders were age, race, alcohol use, non-injection drug use, smoking, type of HAART, and CD4 count from previous visit. In the ALIVE study, confounders were age, injection drug use, alcohol use, smoking, CD4 count from previous visit, non-injection drug use, and type of HAART.