Title: The HIV Care Continuum
Description: The HIV care continuum captures the proportion of people who engage in various steps of the treatment cascade from the time of HIV diagnosis to the achievement of viral load suppression. Viral load suppression is the ultimate goal of HIV treatment as it is the best way to mitigate the spread of HIV and contain the epidemic. The best pathway to viral load suppression is not always clear. There are several factors that aid or hinder HIV patients from engaging in every step of the care continuum until they achieve and sustain viral load suppression. This dissertation aims to measure the underlying enablers of engagement in HIV care, relate them to potential barriers, and assess the effect of each enabler and barrier on future engagement in care and viral load suppression using data collected from people living with HIV (PLHIV) in Eswatini. Firstly, a systematic review was conducted to summarize the methodologies used to measure and analyze barriers and enablers of engagement in HIV care. A search of all peer-reviewed articles published in English globally since 1996 yielded a final selection of 228 articles.

The vast majority of the studies were qualitative and descriptive, and there was a scarcity of quantitative studies utilizing predictive methods that can measure the effect of a barrier or enabler on future engagement in care. Secondly, an empirical analysis was conducted to assess the dimensionality (factor structure) of enablers of engagement in care using a sample largely representative of HIV patients in care in Eswatini. This analysis demonstrated the use of psychometric techniques that can capture underlying latent enablers. These techniques are useful for standardizing the measurements of enablers across studies and programs and can be used to predict future engagement in care. This analysis found financial and access enablers to be the most prominent underlying factors supporting engagement in care in Eswatini, suggesting that these should be an important consideration when designing interventions to retain HIV patients in care in resource-limited settings similar to Eswatini. Thirdly, in an additional empirical analysis, the latent enablers previously identified were used to select potential barriers and assess their effect on linkage to care, retention in care, and viral load suppression.

The analysis also involved an assessment of the mediational pathway from the potential barriers to care to viral load suppression that goes through retention in care. Only perceived HIV stigma was related to any step of the care continuum, with low perceived stigma being marginally associated with less viral load suppression. Retention in care did not mediate the relationship between perceived stigma and viral load suppression. More psychometric studies are needed to standardize the measurement of underlying factors affecting engagement in HIV care. This dissertation demonstrated their utility by measuring latent enablers of engagement in care, assessing the downstream effects of the latent enablers and corresponding barriers, and assessing the mechanisms by which the barriers affect viral load suppression.