Appropriateness of abdominal aortic aneurysm screening with ultrasound: potential cost savings with guideline adherence and review of prior imaging

Objective: To assess the appropriateness of abdominal aortic aneurysm (AAA) screening with ultrasound (US) and potential cost savings by adhering to guidelines and reviewing prior imaging. Methods: Screening aortic US performed in Nova Scotia from January 1 to April 30, 2019, were reviewed. Patient sex, age, risk factors, and study result (negative, <2.5 cm; ectatic, 2.5-2.9 cm; positive for AAA, ≥3 cm) were recorded. Previous imaging tests were reviewed for the presence/absence of aortic ectasia or aneurysm. Appropriateness was based on the Canadian Task Force on Preventive Health Care (CTFPHC) and the Canadian Society of Vascular Surgery (CSVS) guidelines. The number of potentially averted US, subsequent missed positive findings, and cost savings (over the 4-month period) were calculated according to: 1) each guideline; and 2) each guideline combined with review of imaging done 0 to 5 years and 0 to 10 years previously. Results: There were 17 (4.6%) of 369 ectatic aortas and 18 (4.9%) of 369 AAAs. The number of potentially averted examinations, missed ectatic aortas, missed AAAs, and cost savings were as follows, respectively: CTFPHC, 222 (60.2%) of 369, 8, 7, and CAD$20 501.70; CSVS, 117 (31.7%) of 369, 4, 2, and CAD$10 804.95. The model that would yield the greatest cost savings and fewest missed positive findings was the combination of CSVS guidelines with review of prior imaging within 5 years; this would avert 189 (51.2%) of 369 examinations, save CAD$17 454.15 over 4 months, and miss only 2 AAAs and 2 ectatic aortas. Conclusion: Over half of aortic US screening tests can be safely averted by adhering to CSVS guidelines and reviewing imaging performed within 5 years. (author)