Should we screen women for abdominal aortic aneurysm? Analysis of clinical benefit, harms and cost-effectiveness

Background: One-third of UK deaths from ruptured abdominal aortic aneurysm (AAA) are in women. In men, national screening programmes reduce deaths from AAA and are cost-effective. The benefits, harms and cost-effectiveness in offering a similar programme to women have not been formally assessed. Methods: A discrete event simulation model was set up for AAA screening, surveillance and intervention. Relevant women-specific parameters were obtained from sources including systematic literature reviews, national registry/administrative databases, major AAA surgery trials, and UK National Health Service reference costs. Findings: AAA screening for women, as currently offered to UK men (at age 65, AAA diagnosis at an aortic diameter of ≥3.0cm and elective repair considered at ≥5.5cm) gave, over a 30-yeartime horizon, an estimated incremental cost effectiveness ratio (ICER) of £30,000 (95% CI 12,000 to 87,000) per quality adjusted life-year (QALY) gained, with 3,900 invitations to screening required to prevent one AAA-death and an over-diagnosis rate of 33%. A modified option for women (screening at age 70, diagnosis at 2.5cm and repair at 5.0cm) was estimated to be more cost-effective, with an ICER of £23,000 (9,500 to 71,000) per QALY and 1,800 invitations to screening required to prevent one AAA-death, but an over-diagnosis rate of 55%. There was considerable uncertainty in the ICER, largely driven by uncertainty about AAA prevalence, the distribution of aortic sizes for women at different ages and the impact of screening on quality-of-life. Interpretation: By UK standards an AAA screening programme for women, mimicking that in men, is unlikely to be cost-effective. Further research on the aortic diameter distribution in women and potential quality of life decrements associated with screening are needed to assess the full benefits and harms of modified options.