POPULATION-BASED RECORD LINKAGE STUDY OF THE INCIDENCE OF ABDOMINAL AORTIC-ANEURYSM IN WESTERN-AUSTRALIA IN 1985-1994

Background The incidence of abdominal aortic aneurysm (AAA) has increa sed steadily during the past 30 years. Methods Trends in the incidence and surgical intervention for AAA in Western Australia were reviewed for the interval 1985-1994. A population-based health database was use d to link morbidity and mortality records of all patients aged 55 year s or more who died from rupture or were admitted and treated surgicall y for AAA. Three groups were separated for analysis: patients with a r uptured AAA, those admitted for elective repair and those admitted as an emergency with an acute (non-ruptured) aneurysm. Results There was a decline in the incidence of both emergency and elective procedures f or AAA after 1992. While the mortality rate from ruptured AAA has also fallen since 1991, the overall case fatality rate for ruptured AAA ha s fallen by only 1.3 per cent (from 80.7 to 79.3 per cent). Conclusion The decline in mortality rate and emergency procedures may result fro m a fall in the incidence of ruptured AAA, due to an increasing rate o f elective surgery before 1992. The decline in elective procedures fro m 1992 may be due to a fall in the prevalence of AAA owing to high rat es of elective surgery, or to a fall in the incidence of the disease i tself.