Yale Study Finds Hospitalization Rates for Acute Hypertension Have Increased With Widening Racial Disparities

Hospitalizations for acute hypertension among Medicare beneficiaries more than doubled between 1999 and 2019 with the largest increase among African Americans, a Yale-led study has found.

Despite a nationwide effort to promote blood pressure control, health disparities remain persistent among vulnerable populations. For the new study, researchers at Yale’s Center for Outcomes Research and Evaluation (CORE) analyzed national data from almost 400,000 Medicare fee-for-service beneficiaries over age 65 from the Center for Medicare and Medicaid Services (CMS).

The researchers found that overall annual hospitalization rate for hypertensive emergencies increased by 5.64%. Hospitalizations among African Americans increased by 6% during that time. African Americans also had a three times higher hospitalization rate between 2017 and 2019.

The study was published on Nov. 8 in the journal Circulation.

Hypertension control is a national priority for the U.S. Despite greater awareness of the importance of blood pressure management, the national blood pressure control rate declined from 55% to 44% in the past five years. Less than half of all U.S. patients with hypertension achieved their target blood pressure control rate.

“In this paper we looked at hospitalizations for acute hypertension, including hypertension emergency and urgency. These marked elevations in blood pressure require attention and interventions immediately, otherwise they could lead to target organ damage including heart attack and stroke,” said Yuan Lu, ScD, MSc, the lead author of the study and an assistant professor at the Section of Cardiovascular Medicine. “We used the national database from the CMS to evaluate whether we have made any progress in the last 20 years about preventing hospitalization for acute hypertension. And the answer is no.”

Lu trained as an epidemiologist at the Harvard T.H. Chan School of Public Health. She joined CORE six years ago and works with Harlan M. Krumholz, MD, at the intersection of cardiovascular disease prevention, health equity, and digital health.

Hypertensive emergencies often occur in patients with a history of elevated blood pressure. Patients with an elevated risk for target organ damage, including in the heart, kidney, and brain, have a blood pressure at 180 over 120 or higher. Patients with hypertension often do not experience symptoms, so medication nonadherence is common.

“The marked increase in hospitalization rate for acute hypertension represents many more people suffering a potentially catastrophic event that should be preventable,” Lu added.

The study found widening racial disparities in hospitalization for acute hypertension. In 2019, Black Medicare beneficiaries had the highest hospitalization rate across age, sex, race, and dual-eligible subgroups.

“What is most striking is that the rapid increase in racial disparities of hospitalization for acute hypertension between Black and White beneficiaries, with Black people persistently having the higher rates during the last 20 years. This occurred in a time when there has been a tremendous increase in healthcare spending and important national efforts to eliminate disparities,” said senior author Krumholz, the Harold H. Hines Jr. Professor of Medicine and professor of investigative medicine and of public health (health policy) at the Yale School of Public Health and director of CORE.

“The lack of progress in reducing racial disparities in hospitalizations for acute hypertension highlight the need for new approaches to address both medical and nonmedical factors that contribute to such disparities,” Krumholz said.

Using the CMS data, the team made a second discovery by looking at geographical variation in patterns of hospitalization. The highest rates of hospitalization were in the South.

“One of the advantages of our database is that we have data for each county in the U.S.” said Lu. “We found that a vast majority of counties in U.S. have increased hospitalization rates. This suggests the increase in hospitalization rates was nationwide and not strongly associated with a county’s baseline rates. Geographically, the hospitalization rate is highest in the South, which is consistent with what is called a stroke bell in the literature.”

After further analysis, the team hopes to better understand how the U.S. can do a better job in prevention of acute hypertensive admissions.

“For example, we can look at health care utilization in years before patients were hospitalized to understand who are at risk of acute hypertensive admissions and how can events be pre-empted,” Lu added.

The study team also included Yun Wang, Erica S. Spatz, Oyere Onuma, Khurram Nasir, Fatima Rodriguez, and Karol E. Watson.