Elsevier

The American Journal of Medicine

Volume 119, Issue 1, January 2006, Pages 70.e9-70.e15
The American Journal of Medicine

Clinical research study
AJM Online
Racial Differences in Blood Pressure Control: Potential Explanatory Factors

https://doi.org/10.1016/j.amjmed.2005.08.019Get rights and content

Abstract

Purpose

Poor blood pressure control remains a common problem that contributes to significant cardiovascular morbidity and mortality, particularly among African Americans. We explored antihypertensive medication adherence and other factors that may explain racial differences in blood pressure control.

Methods

Baseline data were obtained from the Veteran’s Study to Improve The Control of Hypertension, a randomized controlled trial designed to improve blood pressure control. Clinical, demographic, and psychosocial factors relating to blood pressure control were examined.

Results

A total of 569 patients who were African American (41%) or white (59%) were enrolled in the study. African Americans were more likely to have inadequate baseline blood pressure control than whites (63% vs 50%; odds ratio = 1.70; 95% confidence interval [CI] 1.20-2.41). Among 20 factors related to blood pressure control, African Americans also had a higher odds ratio of being nonadherent to their medication, being more functionally illiterate, and having a family member with hypertension compared with whites. Compared with whites, African Americans also were more likely to perceive high blood pressure as serious and to experience the side effect of increased urination compared with whites. Adjusting for these differences reduced the odds ratio of African Americans having adequate blood pressure control to 1.59 (95% confidence interval 1.09-2.29).

Conclusions

In this sample of hypertensive patients who have good access to health care and medication benefits, African Americans continued to have lower levels of blood pressure control despite considering more than 20 factors related to blood pressure control. Interventions designed to improve medication adherence need to take race into account. Patients’ self-reports of failure to take medications provide an opportunity for clinicians to explore reasons for medication nonadherence, thereby improving adherence and potentially blood pressure control.

Section snippets

Methods

The setting for this study was the Durham Veterans Affairs Medical Center Primary Care Clinics, which involve two sites (hospital-based general medicine clinic and women’s health clinic). There are 30 primary care providers who provide care in this continuity setting.

Patients were enrolled in an ongoing randomized controlled health services intervention trial to improve blood pressure control. The Veteran Study to Improve the Control of Hypertension is a 4-year trial that evaluates both a

Analyses

We conducted 3 sets of logistic regression analyses to assess possible mediating factors in the relationship between race and blood pressure control. The first set of analyses examined the direct association between race and blood pressure control (pathway a) (Figure). Second, the relationship between race and potential mediators of poor blood pressure control were examined using bivariable analyses (pathway b). Last, we examined the relationship between mediators and blood pressure control

Patient Sample

Patients’ mean age was 63 years, 98% were male, 41% were African American, and 59% were white. The proportion of African Americans enrolled in the current study represent the proportion seen in the Durham Veterans Affairs Medical Center. A majority of the sample (68%) were married, and 22% lived alone. Half of the sample (51%) had a high school education or less, 21% reported having inadequate incomes, and 29% were employed. In terms of clinical information, 69% of the sample reported taking

Discussion

In this sample of veterans with hypertension and minimal financial barriers to medical care, there were strong racial differences in blood pressure control. This racial difference was not fully explained by more than 20 potential mediating factors. Our findings confirm previous reports of racial differences in blood pressure control. The findings also suggest that although poor medication adherence is an important component of poor blood pressure control, racial differences in blood pressure

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    This research is supported by the Department of Veterans Affairs, Veterans Health Administration, HSR&D Service, investigator initiative grants 20-034 and 99-275. The views expressed in this article are those of the authors and do not necessarily represent the views of the Department of Veterans Affairs.

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