September 2015
Modeling the Burden of Abdominal Aortic Aneurysm (AAA) in the United States in 2013

Mark Stuntz
Annals of Epidemiology / Annual meeting of American College of Epidemiology
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a b s t r a c t

To estimate the number of prevalent cases of abdominal aortic aneurysm (AAA) and deaths attributable to AAA. 

We used disease modeling software, DisMod II (World Health Organization), to assess AAA burden via a multi-state life table method where differential equations define relationships between incidence, prevalence, and disease-specific mortality. Input data included age- and sex-specific population and allcause mortality, cubic spline interpolation of size- and sexspecific AAA prevalence, and relative risk (RR) estimates of death for persons with AAA compared with persons without AAA, which were adjusted for age, ethnicity, height, weight, smoking, and cardiovascular disease history. 
We estimated 2,347,339 prevalent cases of AAA in the United States in 2013 (90% CI: 2,178,188-2,519,827), resultingin 41,371 deaths attributable to AAA (90% CI: 34,888-47,102). Small AAAs (infrarenal diameter 3.0-3.9 cm) accounted for 72.7% of prevalent cases and 59.1% of deaths, compared with large AAAs (infrarenal diameter   4.0 cm) accounting for 27.3% of prevalent cases and 40.9% of deaths. Females constituted 21.1% of prevalent cases and 45.2% of deaths, compared with males constituting 79.0% of prevalent cases and 54.8% of deaths. 

The burden of mortality attributable to AAA is more than twice that of current estimates from the American Heart Association and Centers for Disease Control and Prevention. Our study reveals that females account for a disproportionately high percentage of deaths despite a low percentage of prevalent cases. Consequently, current screening guidelines should target both sexes, rather than males only.