Driven by rising health care costs at home, nearly 1 million Californians cross the border each year to seek medical care in Mexico, according a new paper by UCLA researchers and colleagues published in the journal Medical Care.

An estimated 952,000 California adults sought medical, dental or prescription services in Mexico annually, and of these, 488,000 were Mexican immigrants, according to the research paper, "Heading South: Why Mexican Immigrants in California Seek Health Services in Mexico."

The paper is the first large-scale population-based research ever published on U.S. residents who travel to Mexico for health services. It is based on an analysis of 2001 data from the California Health Interview Survey (CHIS), the nation's largest state health survey.

"What the research shows is that many Californians, especially Mexican immigrants, go to Mexico for health services," said lead author Steven P. Wallace, associate director of the UCLA Center for Health Policy Research, which conducts CHIS. "We already know that immigrants use less health care overall than people born in the U.S. Heading south of the border further reduces the demand on U.S. facilities."

Cost and lack of insurance were primary reasons both Mexican and non-Mexican U.S. residents sought health services across the border.

Both "long-stay" Mexican immigrants (those in the U.S. for more than 15 years) and "short-stay" immigrants (less than 15 years) have high rates of uninsurance: 51.5 percent of short-stay immigrants and 29 percent of long-stay immigrants do not have medical insurance.

"This points to the importance of expanding work-based insurance in health care reform, since virtually all Mexican immigrants are in working families," said co-author Xochitl Castenada, director of the Health Initiative of the Americas at the University of California, Berkeley.

Both short-stay and long-stay immigrants have even higher rates of uninsurance for dental care: 77.6 percent and 51.6 percent, respectively.


Not surprisingly, dental care was the most common service obtained by immigrants.

Among non-Latino whites, prescription drugs were the most common medical service obtained in Mexico.

Long-stay immigrants used Mexican health services the most, with 15 percent reporting crossing the border during a year's time for health services. Half of these long-stay immigrants lived far "” more than 120 miles "” from the border.

Long-stay immigrants are more likely to be documented than short-stay immigrants, Wallace noted, which makes it easier for them to travel back and forth to Mexico.

Short-stay immigrants "” those most likely to be undocumented "” were also the least likely to need medical care in all areas, with one exception: mental health.

"Undocumented immigrants tend to be younger, stronger and consequently healthier," Wallace said. "But they are also the most stressed out, as many are struggling economically, culturally and linguistically."

Short-stay immigrants who sought treatment in Mexico were more often women and were more likely to tell their doctor they were feeling "sad or down."

Other findings: Immigrants who travel to Mexico for health services are not necessarily the poorest. One explanation: The cost of travel may offset any financial savings, creating a disincentive for the very poor to travel. Although cost was the primary factor in seeking health services, cultural and linguistic barriers and immigration factors were also important motivators.

How often immigrants cross the border to Mexico for health services is particularly relevant to efforts to create and expand binational health insurance plans, Wallace said.

Since 2000, several private insurance companies and at least one employer group have developed such plans, which cover an estimated 150,000 California workers who use Mexican medical facilities near the border.

These plans may be both more cost-effective for employers and more culturally relevant for participants, Wallace said.

"To the extent that binational plans encourage more people to access preventative and other health care, they should be encouraged," he said.