Antiretroviral therapy adherence in resource-limited and resource-rich settings: Current status of knowledge and research priorities

Adherence to highly active antiretroviral therapy is one of the most important factors contributing to treatment efficacy. Although it is one of the most modifiable variables in treatment, it is also among the most difficult to measure accurately. Best estimates of adherence demonstrate that adherence in resource-limited settings is equal or superior to resource-rich settings. Although adherence can be adequate in any setting, it is clear that this is no time for complacency regarding adherence to treatment for HIV infection - whether in developing or developed settings. Emerging evidence indicates that as the duration of treatment increases, adherence may decrease. As a result, there is a pressing need for culturally appropriate and effective interventions for increasing and sustaining adherence in all settings. In this manuscript, we mention a few and review one strategy that has been advocated to improve adherence to TB treatment: directly observed therapy. Few studies have incorporated directly observed therapy for HIV treatment, but preliminary evidence shows compelling, albeit inconclusive, findings. Directly observed therapy does not seem to improve adherence in populations with pre-existing high adherence rates. Further research is urgently needed to improve adherence among children, adolescents and adults through community and family support social networks or by using cellular telephone technology in both resource-limited and resource-rich settings.