Black people with diabetes have worse health outcomes and diabetes management compared to white people. In this study, the researchers wanted to understand if there were certain risk factors for poor diabetes control/outcomes that were more prevalent in black people than white people. The researchers used a case-control study and enrolled 764 black and white patients with diabetes who received care. Cases in the study had poor control over at least two of these three outcomes: HbA1c levels, systolic blood pressure, and cholesterol. Controls were patients with good control over all three. The researchers investigated the following risk factors: depression, low health literacy, poor medication adherence, patients’ capacity to reduce their own cardiovascular risk, and poor communication between patients and their healthcare provider. The researchers found that for black people and not white people, depression and poor medication adherence were associated with a greater chance that they would be labeled as a “case” rather than a “control.” This means that depression and poor medication adherence are risk factors for poor diabetes control in black patients. These risk factors may be important targets to address racial disparities in diabetes control and management.
The researchers wanted to understand if certain risk factors played more of a role in poor diabetes control/outcomes in black patients than in white patients.
Black patients have higher rates of certain diabetes complications than white patients. Studies have found few disparities in the delivery of diabetes care, but substantial disparities in health outcomes still exist especially in HbA1c levels, blood pressure, and cholesterol. These disparities contribute to disproportionate morbidity for black patients compared to white patients.
Self-management of diabetes is critical for preventing complications. There are many factors that increase the risk of poor self-management. For black patients, previous studies have linked depression, low health literacy, poor medication adherence, low capacity to reduce their own cardiovascular risk, and poor communication between patients and their healthcare provider to poor health outcomes. However, there have been no studies that determined which of these factors are most prevalent and predictive of poor health outcomes for black patients with diabetes.
In the Translating Research Into Action for Diabetes (TRIAD) study, black patients have poor HbA1c, blood pressure, and cholesterol compared to whites. In this study, the researchers collected data from a case-control study of patients with diabetes. They examined how the above three health outcomes are associated with certain individual-level risk factors. They hypothesized that each risk factor examined would be more strongly associated with poor diabetes control in black patients than white patients.
764 survey respondents were included in the study. 34% of 557 white patients were cases. 56% of 205 black patients were cases. Differences in the three health outcomes measured were similar for black and white patients.
Without adjusting for demographic factors, missed medication doses and low scores for patient-provider communication quality were significant predictors of case or control status. In adjusted models, no risk factors were associated with case/control assignment for white patients. For black patients, however, depression and missed medication doses were associated with increased probability of being a case.
For patients who reported missing medication doses, black patients gave an average of 2.3 reasons why white patients gave 1.4. In addition, black patients were more likely to endorse the following reasons for poor medication adherence: issues related to lack of knowledge, complexity of medication regimen, dislike of medication and/or side effects, clinical barriers, and forgetfulness.
In this study, depression and missing doses of medication were strongly associated with poor diabetes management in black patients. These risk factors can be modified, and interventions targeting them could be effective in narrowing health disparities between black and white patients with diabetes.
The stronger link between depression and poor diabetes management may be explained by differing depression-related experiences between black and white patients. For example, black patients with diabetes and depression are more likely to report racial discrimination and high levels of stress than those only with diabetes. Interactions between depression and discrimination could influence medication adherence and self-management, especially if recommendations for both are made by a distrusted healthcare system. Developing culturally competent interventions to treat depression in black patients with diabetes may be important in narrowing disparities in diabetes outcomes.
Poor medication adherence in black patients may have resulted from low reported rates of nonadherence in black patients labeled as controls. Or, good adherence in a subset of black patients creates good control over health outcomes, and explains how “resilient” patients are able to overcome other risk factors such as socioeconomic status. Finally, black patients were more likely to report more reasons for missing medication doses, indicating they may have to overcome multiple obstacles to achieve adherence. Enhancing medication adherence could be another effective strategy to eliminate disparities in diabetes health outcomes.
Limitations include lacking statistical power, the case-control design (poor generalizability), and that the study was not longitudinal.
In conclusion, depression and missing medication doses are more prevalent risk factors for developing complications of diabetes in black patients even after adjusting for other demographic factors. The importance of these risk factors must undergo further study in larger populations. These risk factors may be important points for interventions that address racial disparities in diabetes outcomes.
TRIAD is a study of diabetes care in 10 health plans in 6 metropolitan cities in the U.S, including for-profit, non-profit, Medicare, and Medicaid providers. Cases were defined as people with poor control for at least two of the following outcomes: HbA1c, blood pressure, and cholesterol. Controls had good control of all three of these outcomes.
The researchers recruited 1305 eligible patients. 1139 completed the researchers’ survey.
Study variables were drawn from the surveys except for the three health outcomes and BMI. Participants were included if they identified as white or African American. 375 participants were excluded because they were not black or white.
Medication adherence was measured by running out of medication or missing medication doses in the past 6 months. Four reliable scales were used to measure patients’ perceptions of the quality of their communication with healthcare providers. Depression was measured using the PHQ-8. Low capacity for reducing cardiovascular risk was defined as an acknowledgement of high risk of heart disease with the belief that patients could not reduce this risk on their own. A summary score of 4 health literacy items was created. Finally, demographic characteristics including age, sex, education, income, and BMI were also evaluated.
The researchers used SAS’s PROC GLIMMIX program for analysis. They conducted both adjusted and unadjusted analyses to examine associations between risk factors and case/control status. Adjustments were made for age, sex, education, income, and study site.