(Reuters Health) - More than one in four doctors in the United States were born in another country, and a new study suggests many nurses, dentists, pharmacists, and home health aides are also immigrants.

Researchers who analyzed U.S. census data on 164,000 health care professionals found that overall, almost 17 percent weren’t born in America and almost five percent were not U.S. citizens.

“The American health care system relies very heavily on individuals who were born in other countries,” said senior study author Dr. Anupam Jena of Harvard Medical School and Massachusetts General Hospital in Boston.

Past studies have focused on doctors who trained abroad, “but our research shows that skilled immigration from other countries is an important contributor to nearly every occupation within the broader health care industry,” Jena said by email.

Doctors were more likely to be foreign born than other health care professionals, researchers report in JAMA.

About 29 percent of physicians were born in other countries, and almost seven percent were not U.S. citizens, the study found.

Roughly 24 percent of dentists were immigrants to the U.S., and four percent were not citizens.

Among pharmacists, 20 percent were born elsewhere and almost four percent were not citizens.

And 16 percent of registered nurses were immigrants; three percent were not citizens.

Slightly more than 23 percent of home health, psychiatric and nursing aides were born outside the U.S., and almost nine percent were not citizens, the study also found.

Asia sends the most health care professionals to the U.S., accounting for about six percent of the total workforce, followed by Mexico, Central America and the Caribbean, accounting for about five percent of health workers.

The survey was conducted in 2016 by mail, phone, and in person by the U.S. Census Bureau.

It’s possible that some health care professionals surveyed didn’t disclose their immigration or citizenship status, so the study may have underestimated the proportion of workers in the industry who were born outside the U.S., the authors note.

Even so, the results offer fresh evidence that people trained outside the U.S. are helping to expand access to care for many Americans, said Dr. Ahmad Masri of the University of Pittsburgh Medical Center.

“There are shortages in many sectors of healthcare, especially in the underserved communities, which many foreign-born graduates end up serving,” Masri, who wasn’t involved in the study, said by email.

Making it harder for foreign professionals to move to the U.S. and train here would lead to a significant shortage, especially in the most vulnerable underserved areas, Masri said.

“Besides, as we focus more on the wellness of healthcare professionals, the days of working 24/7 non-stop, at least for physicians, are over,” Masri added. “The majority of physicians nowadays value a reasonable work life balance, and that shift would only lead to increase in demand for more healthcare professionals.”

There are also advantages for patients when the health care workforce mirrors the diverse languages and cultures of the population as a whole, said Dr. Vineet Arora of the University of Chicago Pritzker School of Medicine.

“With the increasing diversity of the U.S. population, it’s important our healthcare workforce reflect that diversity,” Arora, who wasn’t involved in the study, said by email. “Certain patients, such as immigrants or those who speak a different language, may prefer or do better with doctors born outside the U.S. due to cultural or language factors.”

SOURCE: bit.ly/2rjq39l JAMA, online December 4, 2018.