Antiretroviral therapy adherence and associated factors in Latvia: a quantitative study

Background

Latvia has one of the highest HIV incidence rates in Europe. Despite full reimbursement of antiretroviral therapy (ART), fewer than half of the 6,061 people living with HIV (PLHIV) receive treatment. Previous prescription data suggested only 2.5% of long-term ART users achieve optimal adherence, but patient-reported evidence is limited. This study estimated ART adherence prevalence and identified factors associated with non-adherence among PLHIV in Latvia.

Methods

A cross-sectional study was conducted within the national project VPP-VM-Sabiedrības_Veselība-2023/5-0001 (Nov 2024–Jun 2025). Adults (≥18 years) receiving HIV care across Latvia were recruited. A total of 368 participants completed an anonymous questionnaire including the Simplified Medication Adherence Questionnaire (SMAQ). Non-adherence was defined per SMAQ criteria. Binary logistic regression identified factors associated with non-adherence, adjusting for gender, age, education, and residence.

Results

Non-adherence prevalence was 77.45% (95% CI: 72.90–81.42). In univariate analysis, higher odds of non-adherence were associated with primary (OR 3.71, p = 0.002) and secondary education (OR 2.11, p = 0.009) vs. university education; identifying as heterosexual (OR 1.95, p = 0.015) or as a person who injects drugs (OR 9.65, p = 0.027); longer HIV duration (OR 1.06/year, p = 0.004); longer ART use (OR 1.11/year, p < 0.001); and higher pill burden (≥2 vs. 1 pill: OR 2.22, p = 0.016). Identifying as a man who has sex with men (vs. not identifying) was associated with lower non-adherence (OR 0.40, p = 0.004). In adjusted models, lower education, longer HIV and ART duration, and higher pill burden remained significant. Gender, age, residence or identifying as a member of a key-population were not associated.

Conclusions

ART non-adherence among PLHIV in Latvia is highly prevalent and mainly linked to educational level and treatment-related factors rather than demographic characteristics or key population status.

Key messages

• ART non-adherence among PLHIV in Latvia is highly prevalent.

• ART non-adherence among PLHIV in Latvia is mainly linked to educational level and treatment-related factors rather than demographic characteristics or key population status.