Decreases in Self-Reported ART Adherence Predict HIV Viremia Among Pregnant and Postpartum South African Women

Abstract

Introduction: Routine HIV viral load (VL) monitoring is recommended for patients on antiretroviral therapy, but frequent VL testing, required in pregnant and postpartum women, is often not feasible. Self-reported adherence can be valuable, but little is known about its longitudinal characteristics.

Methods: We followed women living with HIV from antiretroviral therapy initiation in pregnancy through 18-month postpartum in Cape Town, South Africa, with repeated measurement of VL and self-reported adherence using a 3-item scale. We used generalized estimating equations [with results presented as odds ratios (ORs) with 95% confidence intervals (CIs)] to investigate the association between viremia and change in adherence over pairs of consecutive visits.

Results: Among 2085 visit pairs from 433 women, a decrease in self-reported adherence relative to the previous visit on any of the 3 self-report items, or the combined scale, was associated with VL >50 and >1000 copies per milliliter. The best-performing thresholds to predict VL >50 copies per milliliter were a single-level decrease on the Likert response item "how good a job did you do at taking your HIV medicines in the way that you were supposed to?" (OR 2.08, 95% CI: 1.48 to 2.91), and a decrease equivalent to ≥5 missed doses or a one-level decrease in score on either of 2 Likert items (OR 1.34, 95% CI: 1.06 to 1.69).

Conclusions: Longitudinal changes in self-reported adherence can help identify patients with viremia. This approach warrants consideration in settings where frequent VL monitoring or other objective adherence measures are not possible.

Figure 1.

A) Flow diagram of patient and visit inclusion and B) schematic of visit pairs where the first visit (V0) is the first suppressed visit after ART initiation in pregnancy.

Figure 2.

Proportion of women with adherence scores ≥80 and HIV viral loads ≤1000 copies/mL among 363 women with at least four study visits after V0 (first visit with a viral load ≤50 copies/mL after ART initiation during pregnancy). Data are shown from V0 through 4 additional visits (V1-V4).