Psychiatric morbidity, illicit drug use and adherence to zidovudine (AZT) among injection drug users with HIV disease

Sociodemographic and psychological variables influencing adherence to antiretroviral therapy

OBJECTIVE

To assess the degree of compliance with antiretroviral therapy in HIV-infected patients, and identify which sociodemographic and psychological factors influence it, in order to develop strategies to improve adherence.

DESIGN AND SETTING

Cross-sectional study in a reference HIV/AIDS institution located in Madrid, Spain.

PATIENTS AND METHODS

A total of 366 HIV-infected patients who were on treatment with antiretroviral drugs were invited to complete a questionnaire which recorded sociodemographic data and psychological variables in relation to compliance with the prescribed medication. Clinical information was extracted from the hospital records. The Beck Depression Inventory was used to assess depression, while adherence to treatment was evaluated using patient's self report and the pill count method.

RESULTS

A good adherence to antiretroviral therapy (> 90% consumption of the prescribed pills) was recorded in 211 (57.6%) patients. A good concordance for assessing adherence was found using the patient's self-report and the pill count method in a sub-group of patients. Predictors of compliance in the univariate analysis were age, transmission category, level of studies, work situation, CD4 cell count level, depression and self-perceived social support. In the multivariate model, only age, transmission category, CD4 cell count level, depression, self-perceived social support, and an interaction between the last two variables predicted compliance to treatment; adherence to antiretroviral therapy was better among subjects aged 32-35 years [odds ratio (OR), 2.31; 95% confidence interval (CI), 1.21-4.40], in non-intravenous drug users (IVDUs) (OR, 2.05; 95% CI, 1.28-3.29), subjects with CD4 cell counts from 200-499 x 10(6) cells/l at enrolment (OR, 2.78; 95% CI, 1.40-5.51) and in subjects not depressed and with a self-perceived good social support (OR, 1.86; 95% CI, 0.98-3.53).

CONCLUSIONS

Sociodemographic and psychological factors influence the degree of adherence to antiretroviral therapy. Overall, IVDUs and younger individuals tend to have a poorer compliance, as well as subjects with depression and lack of self-perceived social support. An increased awareness of these factors by practitioners attending HIV-infected persons, recognizing and potentially treating some of them, should indirectly improve the effectiveness of antiretroviral therapy.