[Adherence to antiretroviral drug therapy. A systematic review]

We performed a systematic review of the medical literature in order to determine the level of adherence to antiretroviral therapy and its relation with the social, demographic, and clinical characteristics of patients.

Systematic search of published primary studies in MEDLINE, EMBASE and IME and review of reports presented in main congresses related to infectious diseases and AIDS. Observational and intervention studies carried out in adult patients between 1990 and the first semester of 2001 were selected following descriptive and quality criteria. Both English language and Spanish language reports were analyzed.

30 studies fulfilled previously established requirements. Most studies show high adherence levels between 50% and 80% patients, with a range between 28% and 82%. In univariate or multivariate analyses, factors associated with worse adherence levels were as follows: females, younger people, low education level, low income, active drug consumption, lack of self-perception of the efficacy of antiretroviral agents, stress and lack of motivation, high number of tablets and complexity of administration guidelines. Most prospective studies show a good correlation between adherence and control of HIV infection determined by the measurement of the viral load.

The number of primary studies with methodological quality is limited and future works must be performed under strict design conditions. Most studies show that a high proportion of patients, between 20% and 50%, do not have optimal levels of adherence. Patients with higher adherence levels exhibit greater clinical effectivity. Social, demographic, psychological and other factors related to the lack of adherence must be taken into account in order to improve the compliance in these patients.