Socioeconomic status and response to antiretroviral therapy in high-income countries: a literature review

It has been shown that socioeconomic factors are associated with the prognosis of several chronic diseases; however, there is no recent systematic review of their effect on HIV treatment outcomes. We aimed to review the evidence regarding the existence of an association of socioeconomic status with virological and immunological response to antiretroviral therapy (ART). We systematically searched the current literature using the database PubMed. We identified and summarized original research studies in high-income countries that assessed the association between socioeconomic factors (education, employment, income/financial status, housing, health insurance, and neighbourhood-level socioeconomic factors) and virological response, immunological response, and ART nonadherence among people with HIV-prescribed ART. A total of 48 studies met the inclusion criteria (26 from the United States, six Canadian, 13 European, and one Australian), of which 14, six, and 35 analysed virological, immunological, and ART nonadherence outcomes, respectively. Ten (71%), four (67%), and 23 (66%) of these studies found a significant association between lower socioeconomic status and poorer response, and none found a significant association with improved response. Several studies showed that adjustment for nonadherence attenuated the association between socioeconomic status and ART response. Our review provides strong support that socioeconomic disadvantage is associated with poorer response to ART. However, most studies have been conducted in settings such as the United States without universal free healthcare access. Further study in settings with free access to ART could help assess the impact of socioeconomic status on ART outcomes and the mechanisms by which it operates.