Non-adherence to antiretroviral treatment and associated factors among people living with HIV in Iran: a retrospective cohort study

Introduction: Although combination of antiretroviral therapy (cART) has been successful in improving health outcomes of people living with HIV (PLWH), optimal treatment adherence is required to maintain the benefits. This study aimed to determine factors associated with treatment non-adherence Material and methods: In this cohort study, we included 988 PLWH (1997-2017) living in Southern Iran, Fars Province. Required demographic and clinical data was collected from patients' files. Non-adherence was defined by a physician of the center as skipping a visit or less than 90% intake of prescribed medicines (antiretroviral drugs) in the month preceding to the date of data collection. Results: Of the 988 participants, 70.54% were males. Mean (SD) age of the participants was 35.80 (SD = 8.58) years and treatment non-adherence was found in 17.81% of patients (n = 176). Multiple regression model showed that injection drug use (IDU) (AOR = 2.53, 95% CI: 1.11-5.74%), and history of incarceration (AOR = 4.20, 95% CI: 1.65-10.66%) increased the likelihood of treatment non-adherence, while taking medications for pneumocystis pneumonia (AOR = 0.34, 95% CI: 0.22-0.52%), duration of being under ART (AOR = 0.13, 95% CI: 0.08-0.21%) for 1-5 years, and (AOR = 0.06, 95% CI: 0.02-0.16%) for more than 5 years, decreased the likelihood of treatment non-adherence. Conclusions: These findings show that one in five PLWH did not adhere to cART. On the other hand, the likelihood of non-adherence was directly associated with IDU and incarceration history. Based on the results, tailored programs should be developed to improve adherence among individuals with a history of IDU or incarceration.