Racial differences in the effect of a telephone-delivered hypertension disease management program

Abstract

Background: African Americans are significantly more likely than whites to have uncontrolled hypertension, contributing to significant disparities in cardiovascular disease and events.

Objective: The goal of this study was to examine whether there were differences in change in blood pressure (BP) for African American and non-Hispanic white patients in response to a medication management and tailored nurse-delivered telephone behavioral program.

Participants: Five hundred and seventy-three patients (284 African American and 289 non-Hispanic white) primary care patients who participated in the Hypertension Intervention Nurse Telemedicine Study (HINTS) clinical trial.

Interventions: Study arms included: 1) nurse-administered, physician-directed medication management intervention, utilizing a validated clinical decision support system; 2) nurse-administered, behavioral management intervention; 3) combined behavioral management and medication management intervention; and 4) usual care. All interventions were activated based on poorly controlled home BP values.

Main measures: Post-hoc analysis of change in systolic and diastolic blood pressure. General linear models (PROC MIXED in SAS, version 9.2) were used to estimate predicted means at 6-month, 12-month, and 18-month time points, by intervention arm and race subgroups (separate models for systolic and diastolic blood pressure).

Key results: Improvement in mean systolic blood pressure post-baseline was greater for African American patients in the combined intervention, compared to African American patients in usual care, at 12 months (6.6 mmHg; 95 % CI: -12.5, -0.7; p=0.03) and at 18 months (9.7 mmHg; -16.0, -3.4; p=0.003). At 18 months, mean diastolic BP was 4.8 mmHg lower (95 % CI: -8.5, -1.0; p=0.01) among African American patients in the combined intervention arm, compared to African American patients in usual care. There were no analogous differences for non-Hispanic white patients.

Conclusions: The combination of home BP monitoring, remote medication management, and telephone tailored behavioral self-management appears to be particularly effective for improving BP among African Americans. The effect was not seen among non-Hispanic white patients.

Figure 1.

Estimated (Bars represent 95 % CIs. BP = blood pressure. Estimates are based on a longitudinal data model with unstructured covariance matrix) systolic blood pressure from baseline to 18 months, by intervention group – among African American patients, n = 284.

Figure 2.

Estimated (Bars represent 95 % CIs. BP = blood pressure. Estimates are based on a longitudinal data model with unstructured covariance matrix) systolic blood pressure from baseline to 18 months, by intervention group – among white patients, n = 289.