In this analysis of pooled data from 13 studies in the United States, racial/ethnic disparities in adherence persisted even after controlling for key demographic variables (ie, sex, age, income, education, and site), depression, and substance use. The underlying mechanisms leading to these racial/ethnic disparities remain unclear, although we can speculate based on the experience of individuals of minority race/ethnicity in the United States.
The marginalization experienced by racial/ethnic minorities is the United States can be understood as involving overt discrimination as well as “microaggressions”, which are “brief and commonplace daily verbal, behavioral, or environmental indignities, whether intentional or unintentional, that communicate hostile, derogatory, or negative racial slights and insults toward people of color”.35
As discrimination is related to worse health outcomes and maladaptive health behaviors,36
it may be implicated in worse ART adherence.37
For example, among 152 HIV-positive African American men who have sex with men, Bogart et al38
found that 40% reported racial discrimination in the last 6 months, which was significantly associated in longitudinal analyses with lower adherence. Racial/ethnic minorities who experience discrimination may find it more difficult to trust their providers, a distrust which may also negatively impact adherence. For example, Saha et al39
found that compared with white patients (n = 201), African Americans (n = 1104) expressed lower levels of trust in their provider, which was associated with worse adherence.
Levels of trust in providers may have a basis in experience. A study of 1886 participants (54% white, 28% black, 14% Hispanic) from the HIV Cost and Services Utilization Study21
found that 40% reported having a discriminatory health care experience since their HIV diagnosis and that 24% failed to “completely” or “almost completely” trust their health care providers. In a structural equation model in the same study, discrimination predicted distrust, weaker treatment benefit beliefs, and, in turn, poorer adherence. Distrust seemed to operate on medication adherence by increasing treatment-related psychological distress and weakening treatment benefit beliefs.
Related recent work from Bogart et al38
has pointed to conspiracy beliefs as possible explanations. Among 177 blacks, they identified 2 distinct belief categories: genocidal beliefs (eg, HIV was created by humans) and treatment-related beliefs (eg, people on ART are the government’s guinea pigs). Although both genocidal and treatment-related conspiracy beliefs were related to electronically monitored adherence in univariate analyses, in multivariate tests only the latter were linked to a lower likelihood of optimal adherence at 1 month. Most of this work has been done with African Americans; more work with Latinos is needed.
Health literacy is another possible explanation for racial/ethnic disparities in ART adherence. People with low literacy may not be able to read or identify their medications, which makes it difficult for them to adhere to their prescribed regimens.40
HIV-positive African Americans with low levels of educational literacy have been found to be more nonadherent to ART.41
In addition, Osborn et al42
found that when health literacy was included as a mediator in their analyses, the association of African American race and worse 4-day self-reported ART adherence was reduced to nonsignificance. More specifically, Waldrop-Valverde et al22
investigated numeracy or the ability to understand and use numbers in daily life. They found that poor management of a simulated ARV regimen among African American men and women with HIV was mediated by lower numeracy.
The current research points to many possible directions for future intervention. As Bogart et al43
have pointed out, adherence interventions designed to address culturally specific roots of nonadherence may help to overcome medical mistrust. These might involve culturally tailored components delivered ideally by peer advocates or community-level interventions with recognized popular opinion leaders. Also, future work will need to disaggregate the racial/ethnic categories summarized for convenience here into the broad groupings of “African Americans” and “Latinos.” Earlier work based on the Multi-site AIDS Cohort Study, for example, indicated that blacks of Caribbean descent had worse adherence than those from other regions.12
There may be important Latino subgroup differences as well. We know of no work that has begun to investigate these differences.
Limitations of the present study include the reliance on self-report measures of depression and substance use and their lack of uniformity in measurement across studies. For example, a consistent duration for substance-use assessment across all studies (instead of the actual range of 30–365 days) would have been preferable but would have necessitated our limiting the analyses to the few studies that used the same duration for measurement. Our current analysis represents a conservative estimate of controlling for any substance use at all but may mask the adherence-reducing effects of more intensive substance use. This could potentially affect our main findings if this higher severity of substance use was more common in one racial/ethnic group than another. Our approach to combining the different depression measures, though recommended per Anastasi,30
is limited by the quality of the normative estimates available (Wagner et al31
) and the degree to which the different scales’ items tapped different aspects of depression. The threat to validity is thought to be minimal; however, as the norms are based on very large population samples and there is good overlap of items on these scales. Furthermore, in the prior study we demonstrated that the findings observed using this approach approximated findings obtained from using a more conservative approach of converting raw scores using standard cut-offs for mild/moderate/severe depression across all measures. As such, we are confident in this recoded variable’s ability to control for the effects of depression in the analyses presented here.
Another limitation is that data on all variables were not available from each study, although participants with missing data on depression and substance use were retained in the analyses by creating a category for missing data (ie, a missing indicator approach). A broader assessment of mental health would have been helpful, perhaps validated by clinician rating. Importantly, the MACH14 data set had a limited array of variables available for investigation. Factors we could not include here—such as self-efficacy, social support, housing status, food insecurity, or insurance status—may have accounted for the race/ethnicity and adherence association.
In conclusion, this study of pooled data from 13 different US studies confirmed prior reports of racial/ethnic disparities in ART adherence, even when adherence was more objectively measured and analyses adjusted for key demographic variables, substance use, and depression. The findings may help to explain the worse health outcomes for racial/ethnic minorities with HIV in the United States and suggest a need for interventions targeting their adherence to achieve the US National HIV/AIDS Strategy goal to reduce HIV-related health disparities. There is a need for more research on the mechanisms of these racial/ethnic disparities to inform intervention development and better address these inequities.