: The Alfred Hospital
: Bolton Clarke HIV Program, Melbourne
: Royal District Nursing Service HIV Program, Melbourne was c-author on the first edition
The importance of adherence to antiretroviral therapy
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 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.
Many factors contribute to successful antiretroviral therapy adherence and these include careful assessment, good clinical care, and adherence counselling.  The World Health Organization(WHO) advises assessing adherence with each patient interaction. Nurses are integral to this process given the dynamic role they play in patient care.
The START Study findings (May 2015) demonstrated that starting antiretroviral therapy earlier, when CD4 count is above 500 cells/μL, is preferable to delaying commencing treatment as previously and is reflected in national and international guidelines. With strong evidence to support early treatment initiation and the rationale behind strict adherence, adherence support must remain a component of care from the outset for every person living with HIV.