<p>Quality assessment of selected studies.</p>

A random-effects model using restricted maximum likelihood (REML) with Knapp–Hartung adjustment was used to estimate pooled prevalence and odds ratio. Heterogeneity was assessed using I², τ², and Cochran’s Q test.</p> <p>Results</p><p>A total of 39 studies were included in the final analysis. The pooled prevalence of good ART adherence was 79.4% (95% CI: 74.8%–83.4%), while the pooled viral load suppression rate was 77.5% (95% CI: 72.5%–81.8%).

The pooled odds ratio showed that good ART adherence was strongly associated with viral load suppression (OR = 6.30, 95% CI: 4.84–8.19). Substantial heterogeneity was observed across studies for both adherence and viral suppression outcomes (I² > 90%).</p> <p>Conclusions</p><p>ART adherence and viral load suppression among PLHIV in Ethiopia are relatively high but remain below global targets. Good adherence was significantly associated with virologic suppression, highlighting adherence as a critical modifiable factor for achieving optimal treatment outcomes.

Strengthening adherence support interventions is essential to improve virological success and advance progress toward HIV epidemic control.</p></div>