Asthma control and severity linked with mortality

By Michelle Rizzo

NEW YORK (Reuters Health) - A report in the Annals of Allergy, Asthma, and Immunology suggests that greater asthma severity and poorer perceived asthma control are associated with an increased risk of death in adults with severe asthma.

"Death caused by asthma is a devastating potential outcome," Dr. Theodore A. Omachi, of the University of California, San Francisco, and colleagues write. It can be prevented "if high-risk patients are identified and appropriately treated."

The researchers examined the mortality risk factors in 865 adults admitted to Kaiser Permanente hospitals for asthma. Sociodemographic data, asthma history and severity, health status, and scores on measures of perceived asthma control were recorded and the impact of each factor on mortality risk was assessed.

Patients were followed for an average of 781 days. During the course of the study, 123 patients died. When the analysis was adjusted to consider other potential influences, the researcher detected an association between higher initial severity of asthma scores plus lower perceived asthma control scores and a greater risk of all-cause mortality. A history of former or current smoking was also associated with an increased risk of death.

African American race was not associated with an increased mortality risk compared with non-Latino white race, a finding that contrasts with the results of previous studies, Omachi told Reuters Health.

"It is difficult to be sure of the reason for this surprising finding, but it appears noteworthy that all of the patients in our population had relatively equal access to care...It is also interesting that Kaiser Permanente rolled out a disease management program targeting asthma in the year prior to this study; one could theorize that this played a role in reducing racial disparities by systematizing care."

"One important implication is that we need to place a high priority on providing access to health care in order to reduce racial disparities," Omachi said. "Other researchers have shown that genetic differences play some role in how patients of different races respond to asthma therapies, and these are important findings," he said.

"It is often difficult to separate out whether African Americans have poorer health outcomes because of worse access to care or potentially worse response to medications because of genetic differences," the researcher said.

"Another important finding is that disease management or rehabilitation programs, which attempt to boost the self-confidence and sense of personal responsibility in patients taking care of their asthma, may be important in reducing the risk of death," Omachi added.

SOURCE: Annals of Allergy, Asthma, and Immunology, August, 2008.