The HIV continuum of care paradigm uses a single viral load test per patient to estimate the prevalence of viral suppression. We compared this single-value approach with approaches that used multiple viral load tests to examine stability of suppression.
The retrospective analysis included HIV patients who had at least two viral load tests during a 12-month observation period. We assessed (1) percent with suppressed viral load (<200 copies/ml) based on a single test during observation; (2) percent with suppressed viral loads on all tests during observation; (3) percent who maintained viral suppression among patients whose first observed viral load was suppressed; and (4) change in viral suppression status comparing first with last measurement occasions. Prevalence ratios compared demographic and clinical subgroups. RESULTS
Of 10,942 patients, 78.5% had a suppressed viral load based on a single test, whereas 65.9% were virally suppressed on all tests during observation. Of patients whose first observed viral load was suppressed, 87.5% were suppressed on all subsequent tests in next 12 months. More patients exhibited improving status (13.3% went from unsuppressed to suppressed) than worsening status (5.6% went from suppressed to unsuppressed). Stable suppression was less likely among women, younger patients, black patients, those recently diagnosed with HIV, and patients who missed ≥1 scheduled clinic visits.
Using single viral load measurements overestimated the percent of HIV patients with stable suppressed viral load by 16% (relative difference). Targeted clinical interventions are needed to increase the percent of patients with stable suppression.