Adherence to a medication regime can be defined as ‘the extent to which patients take medication as prescribed by health care providers. Continuous adherence to combination antiretroviral therapy (ART) is paramount to its success in effectively treating human immunodeficiency virus (HIV), achieving virological suppression, preserving immune function, avoiding drug resistance, and preventing opportunistic infections. More broadly, it can confer a public health benefit by reducing what is referred to as community viral load (CVL). Community viral load can be defined as an aggregation of individual viral loads of HIV-infected persons within a defined community. A decrease in community viral load will considerably reduce the likelihood of HIV transmission in that community.

Missed doses, treatment breaks or interruptions, drug holidays, non-use or reluctance to commence antiretroviral therapy pose considerable challenges for clinicians.  The consequences of inadequate adherence to antiretroviral therapy can include the development of drug resistance, limiting the person’s later choice of effective antiretroviral therapy regimes; development of opportunistic illnesses, and increased risk of morbidity and mortality.