The applicability of the Theory of Planned Behaviour in predicting adherence to ART among a South African sample.

We sought to determine the extent to which the Theory of Planned Behaviour (TPB) was applicable in predicting medication adherence among South Africans receiving antiretroviral therapy (ART). Regression analyses revealed that the linear combination of attitudes towards adherence, perceived behavioural control and perceived group norms explained 12 percent of the variance in intentions to adhere to ART. We also found a non-significant relationship between intentions to adhere to treatment and self-reported adherence. The results call into question the extent to which TPB is helpful in understanding a health-promoting behaviour such as medication adherence among South Africans receiving ART.