People in poorer countries in Latin America and the Caribbean adhere better to HIV treatment

16 February 2018

New study provides insights into the factors that influence HIV treatment adherence in Latin America and the Caribbean. Results show that individuals from lower resource settings often achieve higher levels of adherence, contrary to predictions. 

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The Journal of the International AIDS Society has just published the first systematic review of antiretroviral treatment (ART) adherence in Latin America and the Caribbean. The study shows new and unexpected links between countries’ income and adherence.

Understanding ART adherence can provide insights into the expected health outcomes of individuals living with HIV; and in the age of ‘treatment as prevention’, ART adherence can also help us to understand trends in new infections. This is of particular interest in Latin America and the Caribbean where the rate of new infections in the region has remained stable since 2010, with a 5% decrease in the Caribbean and a 0% decrease in Latin America. Identifying low levels of ART adherence, and therefore poor rates of viral suppression in the region could potentially explain why rates of infection have remained so high in Latin America and the Caribbean. 

The researchers reviewed 53 studies from across 25 countries, measuring levels of self-reported adherence. Across the studies, the average adherence rate was 70%. While different thresholds have been used to define optimal adherence, it is estimated that to achieve viral suppression an adherence rate of 95% is needed. The studies, however, varied in how they defined optimal adherence ranging from 65% to 100%. 

Previous studies have found similar levels of ART adherence in sub-Saharan Africa (77%) and India (70%). While lower levels were found in some studies conducted in North America (55%) and Spain (55%).  These results alone suggest that the links between a country’s economy and ART adherence might be more complicated than expected. 

The systematic review revealed that lower-income countries in Latin America and the Caribbean were able to achieve equal if not greater levels of ART adherence. This relationship stood when comparing country income, gross national income and human development index score. 

The researchers note, however, that the ideal trial conditions of the included studies may have been a far cry from the normal level of care received in these countries - meaning that adherence levels reported here could be artificially high. Participants of all the included studies received adherence counselling and other support. The findings showed that social support such as this as well as a good relationship with the physician and satisfaction with the healthcare service were, indeed, all related to improved levels of adherence. 

Furthermore, the study revealed other factors that may have led to poorer levels of adherence among participants in higher-resource settings, including substance misuse, stigma, depressive symptoms and high pill burden.

As encouraging as these results are, the authors were keen to note that previous research has shown that high levels of adherence, such as these, have been found to be less likely to lead to viral suppression in poorer countries. It is thought that the reason for this is that the lack of available viral load monitoring in these settings means that patients in poorer countries can often end up adhering to non-suppressive treatment regimes. So even though these countries have shown that they are able to achieve high levels of adherence, this won’t be enough to bring the rate of new infections down unless coupled with effective viral load monitoring. 

Research like this is important to better understand the gaps in regional HIV responses. Monitoring adherence alongside viral suppression and rates of new infection will allow nations to better target interventions, so that they are able to plug the specific gaps in their response. Targeted responses such as these will help countries to achieve the goals set in the UNAIDS’  political declaration to end AIDS by 2030. For Latin America and the Caribbean, these include reducing new infections to below 40,000 a year and achieving a 90% viral suppression rate among those on ART.

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Written by Francesca Harrington-Edmans

Content Editor