A comprehensive theoretical framework for the implementation and evaluation of opt-out HIV testing.

Opt-out HIV testing (in which patients are offered HIV testing as a default) is a potentially powerful strategy for increasing the number of people who know their HIV status and thus limiting viral transmission. Like any change in clinical practice, implementation of opt-out HIV testing in a health service requires a change management strategy, which should have theoretical support. This paper considers the application of three theories to the implementation and evaluation of an opt-out HIV testing programme: Behavioural Economics, the Health Belief Model and Normalisation Process Theory. An awareness, understanding and integration of these theories may motivate health care providers to order HIV tests that they may not routinely order, influence their beliefs about who should be tested for HIV and inform the operational aspects of opt-out HIV testing. Ongoing process evaluation of opt-out HIV testing programmes (based on these theories) will help to achieve individual health care provider self-efficacy and group collective action, thereby improving testing rates and health outcomes.