Asthma disproportionately affects low-income populations

Low-income Californians with asthma experience more frequent symptoms, end up in the emergency room or hospital more often, and miss more days of work and school, researchers found.

Of the more than 600,000 Californians who experience frequent -- daily or weekly -- symptoms that can signal uncontrolled asthma, a significant proportion (39.1 percent) earn less than 200 percent of the federal government's poverty standard (FPL). In 2007, 200 percent of the FPL for a family of four was $41,300. By contrast, 19.3 percent of those with incomes of 400 percent of the FPL or higher suffer frequent symptoms from their asthma.

Analyzing data from the California Health Interview Survey from 2001 to 2007, the report's authors also found a relationship between poverty and a lack of access to quality health care and repeated exposure to environmental triggers for asthma symptoms, such as smoking and second-hand smoke.

The study calculates the prevalence of asthma among adults and children in California's counties. Those counties with a high percentage of families living in poverty had some of the highest proportions of people currently suffering from asthma. In all counties, however, poverty was associated with asthma.

"The poorest among us suffer most because they lack quality health care and live in high-risk environments," said Ying-Ying Meng, a senior research scientist with the center and co-author of the report. "That disparity also burdens our health system with costly emergency care and hospitalizations and extracts the additional high cost of millions of lost days of work and school.

"Asthma has the potential to be debilitating," Meng added, "but it can be effectively controlled through appropriate medical care and avoidance of triggers."

Health insurance can provide access to the kind of continuous care needed to manage a complex chronic condition like asthma. Yet low-income Californians suffering from the disease were five times as likely to be uninsured (22.1 percent) as their counterparts with asthma earning twice as much (4.4 percent). They were also twice as likely to not have a usual source of care (19.0 percent vs. 8.6 percent) -- a factor that also affects continuity and quality of asthma care.

Health care reforms should provide some relief by extending needed insurance to many low-income asthma sufferers, the report's authors say. But they also encourage policymakers to support asthma education and quality health care that includes access to a patient-centered medical home, case-management programs, specialty referrals and access to around-the-clock advice from a health professional, as well as multilingual and culturally appropriate programs and education.

"These findings are illustrative of how where you live impacts your health. Low-income communities carry the highest disease burden, largely due to inequities that result in unhealthy environments," said Dr. Robert K. Ross, M.D., president and CEO of the California Endowment, which funded the study. "For example, you won't see diesel trucks driving through high-income communities, but you will see many driving through poor communities, spewing exhaust full of particulates that serve as asthma triggers."

The report's authors also call for improvements in sub-standard housing, restrictions on second-hand smoke and other policies that address the environmental factors that contribute to asthma.

Among the findings:

Asthma increasing in California

The prevalence of asthma in California has increased from 11.3 percent in 2001 to 13.0 percent in 2007.

Higher rates in Northern, Central Valley counties

Many Northern and Central California counties -- Lake, Tehama/Glenn, Sutter, Yuba, Contra Costa, Solano, Sacramento, Fresno, Kern, Merced, Madera and San Bernardino -- have asthma rates significantly higher than the state average.

Lost productivity

Californians missed an estimated 1.2 million days of work and 1.6 million days of school because of asthma in 2007. Income was a significant factor: Low-income sufferers missed an average of 2.2 days of work, compared with an average of 0.6 days of work missed by those with higher incomes. Low-income children missed twice as many days of school due to asthma as children from higher-income families.

Preventable urgent care

Rates of emergency department visits for asthma were twice as high among lower-income adults as their higher-income counterparts (18.8 percent vs. 8.8 percent). Low-income children also sought emergency treatment more frequently (23.9 percent vs. 12.5 percent). Hospitalization rates were six times higher for low-income adults.

Read the full report, "Income disparities in Asthma Burden and Care in California."