Background As people with HIV infections age, comorbidities and complications have increased and could affect antiretroviral therapy (ART) adherence.

Purpose To determine the comorbidities of patients with HIV infection, as well as to evaluate their contribution to ART adherence.

Materials and methods A twelve-month retrospective observational study (from January 2012 to December 2012) was conducted in HIV-infected patients who were being treated with ART. ART adherence was the dependent variable. We collected the following independent variables: sex, age, HCV coinfection, transmission risk, CD4⁺ T-cell count, HIV viral load, ART-naive, type of ART and comorbidities. We defined polypathological patients as patients with two or more chronic conditions. Adherence was determined through dispensing pharmacy records (Total number of units dispensed/Total number of units needed×100) and the simplified medicines adherence questionnaire (SMAQ). Patients who took at least 90% of their prescribed ART were classified as good adherers. We performed a univariate logistic regression to determine the relationship between the comorbidities and ART adherence.

Results We included 536 patients in the study (80.2% men, mean age 47 ± 7.1 years) of whom 49.2% were HIV-HCV co-infected. Injected drug use was the main mode of HIV transmission. The median CD4⁺ was 574.5 cells/mm³ (IQR: 353.8–776.3) and viral suppression (<20 copies/ml) was noted in 73.5% of the whole study population. 82.5% were ART-naive overall, antiretroviral regimens were mainly NNRTI-based (40.3%), and 31.5% were receiving a PI-based regimen. We identified 51.9% polypathological patients. The most common comorbidities were: dyslipidaemia (19.4%), neuropsychiatric disorders (14.7%), hypertension (13.2%), diabetes (5.6%) and cardiovascular disease (5.2%). The percentage of adherent patients was 86.2%. The variable polypathological patients (OR = 0.44; CI[0.26–.74]; p = 0.002) showed statistically significant relationships with ART adherence.

Conclusions There is an important number of polypathological HIV-infected patients. Despite ART adherence being high, the presence of these comorbidities significantly reduces adherence.

No conflict of interest.