Background The complexity of highly active antiretroviral treatment (HAART) may be one of the main causes of discontinuation of HAART. Martin et al. in 2007 developed a score which calculates a complexity index considering number of pills taken per day, dosing schedule, dosage form and any specific instructions related to drug use.

Purpose To determine the effect of treatment complexity on medicines persistence in treatment-naive HIV patients.

Material and methods We conducted a retrospective observational study. Treatment-naive HIV patients who started HAART between January 2012 and December 2013 in a secondary hospital were included. The data collected were: age, gender, antiretroviral treatment, complexity index and persistence with the HAART regimen. The complexity index was calculated based on the score developed by Martin et al. Persistence was defined as the length of time from initiation to discontinuation of treatment. Data were collected through outpatient electronic medical records and by reviewing each patient’s medical history. The Kaplan-Meier method was performed using SPSS 20.0.

Results 68 patients were included (93% male, mean age 37 ± 10 years). The most common treatments were a nucleoside reverse transcriptase inhibitor (NRTI) in combination with a non- nucleoside (NNRTI) (72%) followed by a NRTI with a protease inhibitor (PI) (22%). The mean complexity score for the combination of NRTI + NNRTI, 2.1 ± 0.5, was significantly lower than that of the combination NRTI + PI, 4.4 ± 0.5 (difference -2.3, 95% CI: -2.5 to -2.05, p < 0.001). 36 (53%) patients discontinued treatment. The median overall persistence was 55 [95% CI: 37–73] weeks. Persistence with HAART was significantly higher (p = 0.006) for NRTI + NNRTI, 57 [95% CI: 54–60] weeks, in comparison with NRTI + PI, 28 [95% CI 23 to 34] weeks.

Conclusion Patients treated with less complex antiretroviral treatment are significantly more persistent with HAART.

References and/or Acknowledgements 1 AIDS 2011;25:279–90

No conflict of interest.