Successful HIV treatment is contingent on sustained high levels of treatment adherence. Several barriers to optimal adherence have been documented. In this article, we first review the global burden of non-adherence among HIV/AIDS positive individuals on a public health scale. Second, we synthesized available evidence from different study designs and stratified across the European, African, and Asian literature to determine the factors influencing adherence to scheduled clinic appointments and medication non-adherence. Third, we discuss common measurement techniques that quantify the magnitude of non-adherence, their relative advantages and limitations in current practice. From January to May 2018, we reviewed guidelines, standard operating procedures, journal articles, and book chapters on treatment adherence among HIV patients receiving adherence to antiretroviral therapy (ART) globally. We searched PubMed, Medline, Google Scholar, and Cochrane Database of Systematic Reviews with the search terms "adherence," "adherence behavior," "medication adherence," and "HIV patients," or "HIV/AIDS," and "Antiretroviral Therapy" or "ART" or "ARVs" or "highly active ART " from 2000 to 2017. We also identified articles through searches of authors' files and previous research on HIV. We included only papers published in English in this review. We then generated a final list of reference on the basis of originality and the broad scope of this review. We found rich literature evidence of research findings and best practice recommendations on the importance of adherence in HIV/AIDS management, a general understanding of factors associated with non-adherence and approaches to investigating non-adherence behavior among different populations. We observed significant contextual differences exist with regard to barriers and burden of non-adherence among these populations.
Non-adherence remains a significant barrier to achieving successful HIV treatment outcomes. This review aimed to holistically examine the concept of adherence in the light of current research evidence and to provide a basic and adaptable conceptual framework for investigating and influencing adherence behavior among various HIV populations. We reviewed published journal articles and gray literature within the period from 2000 to 2017. A comprehensive search from major online databases and repositories such as PubMed, Scopus, Medline, Google Scholar, and Cochrane Database of Systematic Reviews was conducted using focused search terms that included "social cognition models" or "theories and models of health behavior change" or "behavior change in health psychology" or "theory-based interventions" or "behavioral frameworks" and "adherence behavior" or "medication adherence," and "HIV patients" or "HIV/AIDS." Only papers published in English were included in this study. We found varied and extensive literature evidence supporting the use of psychobehavioral models to promote conceptual understanding of adherence behavior among HIV-positive patients globally. We observed that certain approaches at investigating nonadherence worked better among certain populations and epidemics than others, largely because of contextual differences in barriers and burden of non-adherence among these populations. We synthesized the evidence and applied social cognition models in explaining and providing a basic, evidence-based and adaptable conceptual framework for investigating and influencing adherence behavior among HIV-positive populations around the world, regardless of geographical and HIV epidemiological context.