INTRODUCTION
The Human Immunodeficiency Virus (HIV) belongs to the family of ‘retroviruses’ and possesses the ability to transform its genetic material from viral ribonucleic acid (RNA) into deoxyribonucleic acid (DNA) and then subsequently integrate the latter into the genome of an infected human cell (Maartens, Celum, & Lewin, 2014). These processes, referred to as reverse transcription and integration, combined with a high mutagenicity currently constitute significant barriers to the creation of a cure for the virus. Antiretroviral medications (ARVs) interfere with replication of the virus in specific cells of the immune system (expressing CD4 receptors on their cell surfaces) through varying mechanisms resulting in virologic suppression; characterized by an undetectable level of the virus in the human circulatory system and represents the primary goal of antiretroviral therapy. Indirect benefits that follow virologic suppression include recovery of the immune system; a reduction in AIDS related morbidity; an improved life expectancy and a significant reduction in the risk of transmission of the virus (Cohen, et al., 2016).
The receipt of antiretroviral medications is therefore a lifelong process and for HIV-infected persons to benefit maximally from ARV therapy, they must be optimally retained in care. Retention in HIV care describes the continuous and uninterrupted receipt of comprehensive HIV care and treatment services following HIV diagnosis and successful linkage to care and is an important health behaviour necessary to ensure continuous receipt of antiretroviral medications; evaluation of drug toxicities; early identification of treatment failure (Geng, et al., 2010); and ongoing receipt of comprehensive health education that in turn promotes medication adherence.
From an individual standpoint, retention in care is important as it is a strong predictor of virologic suppression and prolonged survival for persons living with HIV/AIDS (PLHIV) (Colasanti, et al., 2016). Countries of sub-Saharan Africa, particularly South Africa and Nigeria are disproportionately affected by HIV (UNAIDS, 2016); and in these countries, retention in HIV care is a public health priority as intimated by a study that observed that HIV-infected persons who are poorly retained were the most significant source of new HIV infections in the United States (Skarbinski, et al., 2015). From a health promotion standpoint however, retention in care provides an indirect reflection of the readiness of HIV-infected persons to increase control over, and improve their health. Several studies however, suggest that retention in HIV care is sub-optimal both in developed and developing countries (McCutchan, 2009).
In a recent study conducted in the United States, retention rates were observed to decline from 84% to 60% and 49% at 12, 24 and 36 months post-initiation of antiretroviral therapy, respectively (Colasanti, et al., 2016). In sub-Saharan Africa, the earliest systematic review of retention in HIV care observed that among 74,000 HIV-infected persons across 13 countries, the proportion of persons who were alive and receiving ARVs 24 months post-initiation of treatment was approximately 60% (Rosen, Fox, & Gill, 2007). In an updated meta-analysis published in 2010, the authors observed that 24- and 36-month retention rates for 226,307 persons from 39 patient-cohorts was 70% and 64.6% respectively (Fox & Rosen, 2010). In Nigeria, most studies conducted to assess retention rates have been cross-sectional in nature. In one study, 75% of 3,878 HIV-infected adults who started ARVs between 2005 and 2009 across 37 treatment facilities in Nigeria were retained in care by 2010 (Ugoji, et al., 2015). In another cross-sectional study conducted in Ekiti state, only 63% of HIV-infected persons who started ARVs between 2005 and 2011 at a large tertiary hospital were retained in care by 2012 (Babatunde, et al., 2015). Cross-sectional analyses typically over-estimate retention rates and do not provide information on changes in retention rates over time.
Several studies have also been conducted to determine factors that predict retention in HIV care including demographic factors such as younger age, male gender, lower level of education and socio-economic status; availability of social support; adherence counselling; disclosure of HIV status; presence of severe mental illness; clinic related factors; HIV disease progression and HIV sero-discordance (Bulsara, Wainberg, & Newton-John, 2016). In the study of factors influencing this important health behaviour (retention in HIV care); most studies failed to conceptualize their research using a theory of health behaviour.
It is therefore on the premise of the large disease burden in sub-Saharan Africa particularly Nigeria; coupled with limitations of existing studies that this study sort to determine how retention rates varied over time while also determining barriers and facilitators of retention in HIV care in Nigeria.
The specific objectives are to:
Research questions that guided this study were the following:
Sub-optimal retention in HIV care has deleterious effects both from the individual and public health perspective. Poor retention in HIV care has been linked with poor medication adherence, development of antiretroviral drug resistance and an increased risk of death from Acquired Immunodeficiency Syndrome (AIDS) – the hallmark of HIV infection characterized by severe, debilitating and life-threatening opportunistic infections. From a public health standpoint, interventions to promote retention in HIV care are needed in order to reduce the transmission and incidence of new HIV infections within communities; reduce the burden placed on an already weak healthcare system as well as reduce healthcare costs associated with HIV treatment, prevention and control. HIV-infected persons who are poorly retained in care typically have higher viral loads and are significantly more likely to transmit the virus to others. In high burden settings like Nigeria, there is therefore an important need to employ health promotion strategies that promote health literacy through health education both for infected individuals and the communities they reside in.
This study is unique as it is one of a few studies conducted in Nigeria to estimate retention rates longitudinally, over a 36-month period thus, providing a more accurate estimate of retention among HIV-infected persons on antiretroviral treatment. Furthermore, this study conceptualized using the socio-ecological model also elicited barriers and facilitators of optimal retention in HIV care in Nigeria. The results of this study contribute new knowledge that will act as a roadmap guiding the design and implementation of effective interventions to improve retention in HIV care in Nigeria.
Antiretroviral Treatment (ART): is a combination of at least 3 potent antiretroviral medications used in the lifelong management of HIV
HIV Continuum of Care: is a framework that describes the various steps that persons living with HIV must proceed through in order to achieve virologic suppression namely diagnosis, linkage to HIV care and ART eligibility assessment, initiation and maintenance of ART and the achievement of viral suppression.
Virologic Suppression: is the suppression of HIV viral load to levels below 1,000 viral copies per millilitre (ml) of blood due to inhibition of replication by antiretroviral medications.
Retention in HIV Care: the continuous and uninterrupted receipt of comprehensive HIV care and treatment services following successful linkage to care; operationalized in this study, as ‘4-month hospital visit constancy’ or the ‘number of 4-month intervals with at least 1 clinic visit’.
HIV Treatment Naive: refers to HIV-positive persons who have never been initiated on or taken any antiretroviral medications for HIV.
HIV Treatment Experienced: refers to HIV-positive persons who have been initiated on antiretroviral medications at any time since they were diagnosed with HIV.