Phillips TK, Wilson IB, Brittain K, Zerbe A, Mellins CA, Remien RH, Orrell C, Abrams EJ, Myer L.
J Acquir Immune Defic Syndr. 2018 Nov 5. doi: 10.1097/QAI.0000000000001909. [Epub ahead of print]
Routine HIV viral load (VL) monitoring is recommended for patients on antiretroviral therapy (ART) 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.
We followed women living with HIV from ART initiation in pregnancy through 18 months postpartum in Cape Town, South Africa, with repeated measurement of VL and self-reported adherence using a three-item scale. We used generalized estimating equations (with results presented as odds ratios [OR] with 95% confidence intervals [CI]) to investigate the association between viremia and change in adherence over pairs of consecutive visits.
Among 2085 visit pairs from 433 women, a decrease in self-reported adherence relative to the previous visit on any of three self-report items, or the combined scale, was associated with VL >50 and >1000 copies/mL. The best performing thresholds to predict VL >50 copies/mL 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 1.48-2.91), and a decrease equivalent to ≥5 missed doses or a one level decrease in score on either of two Likert items (OR 1.34 95% CI 1.06-1.69).
Longitudinal changes in self-reported adherence can help identify patients with viremia. This approach warrants consideration in settings where frequent viral load monitoring or other objective adherence measures are not possible.