Nonoptimal Virological Response Among Adults Living With HIV After Initiation of Combined Antiretroviral Therapy at a Tertiary Hospital in Oman: A Retrospective Cohort Study, 1992-2024.

backgroundCombined antiretroviral therapy (cART) has transformed HIV infection from a life-threatening condition into a manageable chronic disease by reducing viral replication, preserving immune function, and lowering HIV-related morbidity and mortality. Nevertheless, achieving and maintaining viral suppression remains an important challenge. Evidence regarding factors associated with nonoptimal virological response among people living with HIV in Oman remains limited.

aimThis study investigated factors associated with nonoptimal virological response among adults living with HIV who initiated cART and received follow-up at the Royal Hospital, Oman, between 1992 and 2024.

methodsA retrospective cohort study was undertaken at the Royal Hospital, Muscat, Oman, the national tertiary referral center for HIV care. The analysis included 549 adults aged ≥ 18 years who initiated cART and had the laboratory and clinical information required for the study. Participants were eligible if they had two consecutive HIV RNA measurements, both obtained at least 6 months after cART initiation. Optimal viral suppression was defined as HIV RNA ≤ 20 copies/mL, whereas nonoptimal virological response was classified only when both consecutive HIV RNA measurements were > 20 copies/mL, based on the laboratory and clinical monitoring threshold used at the Royal Hospital and Ministry of Health guidance. Participants with only one eligible measurement or discordant measurements were not classified as having a nonoptimal virological response. Clinical information was retrospectively retrieved from electronic medical records. Data were analyzed using IBM SPSS Statistics Version 28. Multivariable Poisson regression with robust variance was used to estimate adjusted risk ratios (aRRs) and corresponding 95% confidence intervals (CIs). Statistical significance was considered at p ≤ 0.05.

resultsOf the 549 participants, 321 (58.5%) had HIV RNA ≤ 20 copies/mL and 228 (41.5%) had HIV RNA > 20 copies/mL. Compared with individuals diagnosed in 2020 or later, the risk of nonoptimal virological response was higher among those diagnosed in 2008 or earlier (aRR: 2.166, 95% CI: 1.160-4.043) and those diagnosed between 2009 and 2014 (aRR: 2.273, 95% CI: 1.258-4.107). Male participants had a higher risk than female (aRR: 2.154, 95% CI: 1.172-3.960). Diagnosis through antenatal care was also associated with nonoptimal virological response (aRR: 3.662, 95% CI: 1.263-10.618), although the estimate should be interpreted cautiously because of the small number of participants in this category. WHO clinical Stage 3 was associated with a lower estimated risk compared with Stage 4, although the association was not statistically significant (aRR: 0.592, 95% CI: 0.349-1.005; p = 0.052). Participants with hemoglobin levels ≤ 10 g/dL also had an increased risk of nonoptimal virological response (aRR: 1.676, 95% CI: 1.020-2.753).

conclusionFive sociodemographic and clinical factors were independently associated with detectable HIV RNA among adults receiving cART in Oman: sex, period of HIV diagnosis, antenatal testing, WHO clinical stage, and hemoglobin concentration. These findings support continued efforts to identify patients who may require closer clinical monitoring and individualized support to achieve and maintain viral suppression.