Hidden health disparities emerge when Asian American data is disaggregated

Two large studies released this month found that commonly used racial categories in U.S. health data obscure significant disparities among Asian American patients. When researchers analyzed heart failure treatment and pregnancy-related high blood pressure by specific ethnic groups, patterns of unequal care and elevated risk emerged. The results suggest that broad data labels may be undermining efforts to prevent serious cardiovascular and maternal complications.

A study published in the Journal of the American College of Cardiology examined heart failure treatment across more than 700,000 hospitalizations at over 800 U.S. hospitals between 2015 and 2023. Researchers found that when Asian American patients were analyzed as a single group, differences in care were largely hidden. After disaggregating the data, Filipino and Vietnamese patients were found to be less likely than other Asian subgroups to receive complete guideline-recommended heart failure care, including certain medications and discharge planning practices.

While the study did not find large differences in overall mortality rates, it identified disparities in care quality that could affect long-term outcomes. Researchers noted that many hospitals continue to rely on broad racial categories that do not reflect cultural, linguistic and socioeconomic differences across Asian American communities. They suggested that factors such as limited English proficiency, access to care and differences in health system navigation may contribute to the observed gaps.

A separate study in the Journal of the American Heart Association analyzed nearly 773,000 pregnancy records from California between 2007 and 2019 involving individuals who identified as Asian American, Native Hawaiian or Pacific Islander. The researchers found substantial variation in pregnancy-related high blood pressure across ethnic subgroups. Chinese individuals had the lowest rate at 3.7 percent, while Guamanian individuals had the highest at 13 percent.

After accounting for age, income, insurance status and preexisting conditions, Filipino and several Pacific Islander groups were found to have two to three times the risk of pregnancy-related hypertension compared with Chinese individuals. Japanese, Korean and Vietnamese individuals generally did not show elevated risk. Jennifer Soh of Stanford University School of Medicine said, “There are known ways to help prevent and treat high blood pressure during pregnancy. Our findings can help health care professionals identify those who are at higher risk.”

Both studies underscore how aggregated racial data can obscure health risks and limit effective prevention strategies. Pregnancy-related hypertension is a leading cause of maternal illness and death in the U.S. and increases long-term risk of heart disease and stroke. Similarly, gaps in heart failure care can affect survival and quality of life. Researchers and public health experts say more precise data collection could help clinicians better identify at-risk patients and tailor interventions earlier. Such findings add urgency to calls for disaggregated health data to improve equity and outcomes across diverse communities.