SAN DIEGO – Between 1999 and 2010, age-adjusted deaths from asthma in the United States declined modestly but significantly, deaths from angioedema increased significantly, and deaths from anaphylaxis remained stable.
Those are key findings from an analysis of Centers for Disease Control and Prevention (CDC) data presented by Dr. Susan J. Kim at the annual meeting of the American Academy of Allergy, Asthma, and Immunology.
Dr. Kim, a first-year allergy fellow at Kaiser Permanente Los Angeles Medical Center, and her associate, Jordan C. Brooks, Ph.D., set out to document the number of deaths in the United States in which asthma or allergy played a role between 1990 and 2010, and to determine if there have been secular trends in the incidence of such deaths. The researchers queried the CDC’s online Multiple Cause of Death compressed mortality file for International Classification of Disease (ICD-10) codes relating to asthma, urticaria, angioedema, and anaphylaxis, and proceeded to calculate age-adjusted death rates for 1999-2004 (early period) and 2005-2010 (late period).
Dr. Susan J. Kim
During the overall time period, there were 113,778 deaths from asthma of all types, 908 from angioedema, and 2,448 from anaphylaxis. Dr. Kim reported that the total number of deaths from asthma of all types (including status asthmaticus) dropped from 57,935 in the early period to 55,843 in the late period. This represented a significant decline, from a rate of 3.38 per 100,000 persons to 2.95 per 100,000 persons.
Blacks had a significantly higher rate of mortality from asthma than whites (5.85 per 100,000 persons vs. 2.55 per 100,000 persons). "This racial disparity might be attributed to a discrepancy in access to quality medical care and use of medications," Dr. Kim said.
She went on to note that women had a higher rate of mortality from asthma than men (3.61 per 100,000 vs. 2.56 per 100,000). "This is interesting, because when taking all causes of mortality in the United States – cardiovascular disease, malignancy, et cetera – men have a higher mortality rate," she said. "The cause may be due to estrogen and progesterone’s effects on airway contractility and immune function."
The researchers observed a significant increase in total deaths from angioedema, from 0.0157 per 100,000 persons during the early period to 0.0289 per 100,000 persons during the late period. "Perhaps an explanation is that there is a lack of awareness that life-threatening laryngeal attacks and asphyxiation can occur," Dr. Kim hypothesized.
At the same time, no significant trends in anaphylaxis death occurred between the early and late periods. Overall, the death rate from anaphylaxis was 0.0637 per 100,000, or 0.6 per million people. "This mortality rate remained stable between our two time periods," she said. "Previous estimates have ranged from 0.5 and 5.5 per million people."
Dr. Kim acknowledged certain limitations of the study, including the fact that the CDC database used for the analysis is subject to missing data, variability in coding, and miscoding. "There’s also no way for us to know how race was identified," she said. "It also lacked clinical details, including the sequence of events leading to death, and medication reconciliation."
Dr. Kim had no relevant financial conflicts to disclose.