Adherence to Antiretroviral Medications among Persons who Inject Drugs in Low and Middle Income Countries: An international systematic review

Background: Adherence to antiretroviral (ARV) medication is vital to reducing overall morbidity and mortality among HIV infected persons. People who inject drugs (PWID) represent a population at an elevated risk for HIV. In this review, we assess adherence levels to ARVs among HIV positive PWID in TLMIC.
Methods: Systematic review was conducted to locate studies documenting adherence to ARVs among samples of PWID in TLMIC. Studies had to include at least 90% drug injectors with longitudinal measures of ARV adherence. Meta-analysis of adherence levels were calculated along with variation among study results.
Results: There were 15 studies were included in the review, representing 7 different countries; n=21258. Follow-up periods ranged from 30 days to 12 years (average: 27 months). Adherence levels ranged from 33% to 97%; the average rate was 72%. Heterogeneity among studies was very high (I² = 99.7%). Meta-regression showed higher adherence was associated with more precise measurement of adherence (over shorter time periods) and in studies conducted in Eastern Europe and East Asia.
Conclusions: The great heterogeneity in results precludes generalization to TLMIC as a whole. Given the critical importance of ART adherence, more research is needed on ARV adherence among PWID in TLMIC. Using standardized methods for conducting the research will be important, and initial recommendations for standardized methods based on this review will be presented. These will include: 1) use of multiple methods for assessing adherence, 2) description of program policies and procedures, and 3) use of guidelines for transparent reporting (CONSORT, TREND, MOOSE).