Mexico’s new pilot universal health insurance system has dramatically reduced household-crippling expenditure on healthcare for both poor families and the general population, according to a study led by Harvard University researchers. Seguro Popular, as the 2003 program is called, reduced by 23 percent the proportion of households experiencing catastrophic expenditures, defined as when a household’s health spending exceeds 30 percent of its capacity to pay. The program aims to reduce catastrophic health expenditures by providing social protection in health, according to the study in The Lancet.

“That Mexico may now have a validated architecture for delivering health services to the poor seems to be the most surprising and encouraging result from this experiment,” the report says. “We found that the stewardship of Seguro Popular has been successful in reducing overall catastrophic and out-of-pocket expenditures for inpatient and outpatient medical procedures, especially in the poorest individuals.”

The study involved randomly assigning treatment within 174 matched pairs of communities, representing 118,569 households in seven Mexican states, and measured outcomes in a baseline survey (August to September 2005) and a follow-up survey 10 months later (July to August 2006) in 50 of these pairs. The treatment included enrolling in a health-insurance program that was free to the poor as well as upgraded medical facilities and services. Participant states also received funds to improve health facilities and to provide medications for services in treated communities. Meanwhile, control communities received nothing extra.

The reduction in catastrophic-health expenditures seen from Seguro Popular translated into a reduction in health spending across all responders of 426 pesos (US$ 31). Contrary to expectations and previous observation research, no effects were found on medication spending, health outcomes, or utilization of healthcare, researchers say.

Mexico developed Seguro Popular to provide healthcare to 50 million Mexicans—roughly equal to the number of uninsured in the United States—who otherwise would lack coverage. Voluntary enrollment in the program, provided at no cost to the poor, offers access to health clinics, medications, regular and preventive medical care, and the money to pay for it, researchers say.

The researchers add that although resources reached the poor, the program did not show some other effects, possibly due to the short duration of treatment (10 months). They say that further experiments and follow-up studies, with longer assessment periods, “are needed to ascertain the long-term effects of the program.”