BackgroundAdherence to combination antiretroviral therapy (ART) is a key predictor of the success of human immunodeficiency virus (HIV) treatment, and is potentially amenable to intervention. Insight into predictors or correlates of non-adherence to ART may help guide targets for the development of adherence-enhancing interventions. Our objective was to review evidence on predictors/correlates of adherence to ART, and to aggregate findings into quantitative estimates of their impact on adherence.MethodsWe searched PubMed for original English-language papers, published between 1996 and June 2014, and the reference lists of all relevant articles found. Studies reporting on predictors/correlates of adherence of adults prescribed ART for chronic HIV infection were included without restriction to adherence assessment method, study design or geographical location. Two researchers independently extracted the data from the same papers. Random effects models with inverse variance weights were used to aggregate findings into pooled effects estimates with 95% confidence intervals. The standardized mean difference (SMD) was used as the common effect size. The impact of study design features (adherence assessment method, study design, and the United Nations Human Development Index (HDI) of the country in which the study was set) was investigated using categorical mixed effects meta-regression.ResultsIn total, 207 studies were included. The following predictors/correlates were most strongly associated with adherence: adherence self-efficacy (SMD = 0.603, P = 0.001), current substance use (SMD = -0.395, P = 0.001), concerns about ART (SMD = -0.388, P = 0.001), beliefs about the necessity/utility of ART (SMD = 0.357, P = 0.001), trust/satisfaction with the HIV care provider (SMD = 0.377, P = 0.001), depressive symptoms (SMD = -0.305, P = 0.001), stigma about HIV (SMD = -0.282, P = 0.001), and social support (SMD = 0.237, P = 0.001). Smaller but significant associations were observed for the following being prescribed a protease inhibitor-containing regimen (SMD = -0.196, P = 0.001), daily dosing frequency (SMD = -0.193, P = 0.001), financial constraints (SMD -0.187, P = 0.001) and pill burden (SMD = -0.124, P = 0.001). Higher trust/satisfaction with the HIV care provider, a lower daily dosing frequency, and fewer depressive symptoms were more strongly related with higher adherence in low and medium HDI countries than in high HDI countries.ConclusionsThese findings suggest that adherence-enhancing interventions should particularly target psychological factors such as self-efficacy and concerns/beliefs about the efficacy and safety of ART. Moreover, these findings suggest that simplification of regimens might have smaller but significant effects.Electronic supplementary materialThe online version of this article (doi:10.1186/s12916-014-0142-1) contains supplementary material, which is available to authorized users.

In a cohort of largely well suppressed HIV-positive participants and HIV-negative controls, HIV-positive status was significantly and independently associated with worse physical and mental HRQL and with an increased likelihood of depression. Our finding that a higher number of comorbidities was independently associated with worse physical HRQL reinforces the importance to optimize prevention and management of comorbidities as the HIV-infected population continues to age.

HIV infected and tuberculosis (TB) patients need high levels of treatment adherence to achieve optimal treatment outcomes. We conducted a pilot-study on real time medication monitoring (RTMM) in a resource-limited setting. We enrolled five HIV infected and five TB patients from Kilimanjaro, Tanzania. They took their medication using RTMM. When the device was not opened on time, patients received a reminder SMS. After 3 months, we interviewed patients. Six patients (60 %) reached adherence of >95 %. Nine-hundred-twenty-two of 1104 intakes (84 %) were on time. Five-hundred reminders (45 %) were sent, of which 202 (40 %) were incorrect, because of an unstable mobile network. Nine patients found the device helpful and nine mentioned it keeps medication safe. Six patients reported that the size was too big. Five patients mentioned they received incorrect reminders. The device is considered useful in Kilimanjaro. Optimization of the device should consider network connectivity and the size of the device.

Stratifying patients according to their socially desirable response set improved the prediction of virological treatment response by self-reported adherence. This finding emphasizes the importance of discussing medication adherence with patients in a non-threatening and non-judgemental way that normalizes non-adherence in order to reduce socially desirable responding.