Optimal Adherence Window for ART May be Larger in HIV Treatment

A recent study found that optimal adherence for antiretroviral therapy (ART) for HIV infection could possibly be a larger window than the traditional ≥95%.

Although treatment for HIV is effective, suboptimal adherence to treatment can result in viral suppression and promote drug-resistant strains, which can then lead to regimen failure and progression to AIDS, according to a study published by Medicine.

An optimal adherence rate of ≥95% is needed to be met by patients taking newer medications. This high adherence rate has proven to be a barrier for the initiation of treatment in the early stages of HIV.

Researchers conducted a meta-analysis to evaluate the association between reaching optimal adherence to ART and virologic outcomes. They used meta-regression in order to determine the factors that could moderate the relationship between adherence and virologic outcomes, according to the study.

Researchers evaluated a total of 43 studies with 27,905 participants that met the inclusion criteria. Included were 25 prospective studies that reported virologic failure according to adherence. The remaining studies were randomized controlled trials and retrospective analyses.

Of the 27,905 participants included in the analysis, 22,740 had a viral load and adherence measurement. There were 7056 participants with virologic failure. Only 23% of participants had optimal adherence to ART and 47% were classified as having suboptimal adherence and virologic failure.

Researchers said their findings suggest an adherence level of 80 to 90% may be adequate for viral suppression in patients taking new ART drugs, which may encourage the prescribing of the drugs earlier, according to the study.

Overall, researchers found that virologic failure occurred much more often in patients with suboptimal adherence compared with those who had optimal adherence.

Researchers concluded that adherence is key to better clinical outcomes, however, the data analyzed suggests the threshold for optimal adherence is wider than the common ≥95%. While researchers suggest patients should be instructed to attain this adherence, slightly lower adherence should not stop the prescribing of ART during an early stage of HIV infection.