What began as a graduate classroom project at the University of Miami Miller School of Medicine developed into a peer-reviewed study published in the American Journal of Public Health examining how birthplace and national origin shape drug overdose mortality among Black and Hispanic adults in Florida.

Researchers analyzed Florida mortality records from 2021 through 2024 and population estimates from the American Community Survey. Instead of treating Hispanic and Black adults as uniform populations, they examined mortality according to birthplace and national origin. 

U.S.-born Black adults experienced more than six times the overdose mortality of Caribbean-born Black adults. Among Hispanic populations, U.S.-born and Puerto Rican-born adults had the highest mortality, while most foreign-born Hispanic populations experienced substantially lower rates. 

From Classroom Project to Publication

Saurabh Kalra, M.S., M.P.H., a Ph.D. candidate in epidemiology, led the study with senior author Paulo S. Pinheiro, M.D., Ph.D., a research professor in the Department of Public Health Sciences. 

Dr. Pinheiro developed the project for his Chronic Disease Epidemiology course to give students experience using statewide population data to investigate an urgent public health issue.

Kalra worked with Anna Hernandez, M.P.H., and Eduardo L. Hernandez, M.P.H., who were M.P.H. students at the time. Amrit Baral, Ph.D., a graduate of the University of Miami epidemiology doctoral program who is now a postdoctoral fellow at the Johns Hopkins Bloomberg School of Public Health, later joined the research team. 

“One of the strengths of our graduate program is that students work with real population health data to address important public health questions,” Dr. Pinheiro said. “It’s especially rewarding to see a classroom project evolve into a publication in the American Journal of Public Health.” 

Differences Within Population Groups

After accounting for age, sex and educational attainment, overdose mortality among U.S.-born Black adults remained 6.4 times higher than among Caribbean-born Black adults. 

U.S.-born Hispanic and Puerto Rican-born adults each experienced 3.8 times the overdose mortality of South American-born adults. Lower educational attainment was associated with higher mortality across the populations studied, but education did not fully explain the differences associated with birthplace. 

“Florida is one of the most diverse states in the country, yet overdose statistics are typically reported using broad racial and ethnic categories,” Kalra said. “By examining birthplace and national origin, we found that the greatest burden falls on U.S.-born populations. These are disparities that would remain largely invisible if we relied only on traditional racial and ethnic classifications.” 

The researchers said the findings are consistent with the “healthy immigrant effect,” an epidemiologic pattern in which first-generation immigrants may experience better health outcomes than U.S.-born populations despite socioeconomic disadvantages. 

Potential explanations include differences in lifetime exposure to the U.S. illicit drug supply, social environments and generational patterns of substance use. Additional research is needed to understand the factors contributing to these differences. 

Strengthening Overdose Surveillance

Overdose surveillance commonly relies on broad racial and ethnic classifications. Incorporating information about birthplace and national origin could help public health agencies identify populations facing greater risk and direct prevention resources more precisely. 

“Our findings show that birthplace and national origin are not simply demographic characteristics—they identify populations experiencing very different levels of overdose risk,” Dr. Pinheiro said. “Incorporating these measures into routine public health surveillance could help ensure prevention resources reach the communities that need them most.” 

The findings demonstrate how disaggregated population data can strengthen overdose surveillance while illustrating how classroom research can contribute evidence to public health practice. 

Written by Deycha Torres Hernández, published September 19, 2026.