Cost-Effectiveness of Screening Women for AAA

Study Questions:

What are the benefits, harms, and cost-effectiveness of screening programs for abdominal aortic aneurysm (AAA) in women?

Methods:

The investigators developed a decision model to assess predefined outcomes of death caused by AAA, life-years, quality-adjusted life-years, costs, and the incremental cost-effectiveness ratio for a population of women invited to AAA screening versus a population who was not invited to screening. 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 or administrative databases, major AAA surgery trials, and UK National Health Service reference costs. Secondary outcomes included the number of women who were overdiagnosed (screen-detected AAAs in which the disease would without screening have remained without symptoms or incidental detection), and the number of women who were overtreated (repairs of screen-detected AAA that would without screening not have resulted in AAA death or surgery).

Results:

AAA screening for women, as currently offered to UK men (at age 65 years, with an AAA diagnosis at an aortic diameter of ≥3.0 cm, and elective repair considered at ≥5.5 cm) gave, over 30 years, an estimated incremental cost-effectiveness ratio of £30 000 (95% confidence interval, 12 000–87 000) per quality-adjusted life-year gained, with 3,900 invitations to screening required to prevent one AAA-related death and an overdiagnosis rate of 33%. A modified option for women (screening at age 70 years, diagnosis at 2.5 cm and repair at 5.0 cm) was estimated to have an incremental cost-effectiveness ratio of £23 000 (9500–71 000) per quality-adjusted life-year and 1,800 invitations to screening required to prevent one AAA-death, but an overdiagnosis rate of 55%. There was considerable uncertainty in the cost-effectiveness ratio, largely driven by uncertainty about AAA prevalence, the distribution of aortic sizes for women at different ages, and the effect of screening on quality of life.

Conclusions:

The authors concluded that an AAA screening program for women, designed to be similar to that used to screen men, is unlikely to be cost-effective.

Perspective:

This study reports that population AAA screening of women would yield little benefit and is not economically acceptable. Furthermore, screening could lead to more overdiagnosis and overtreatment. Additional research on the population-based aortic size distribution in women is needed, to provide a female-specific definition of AAA, together with better quantitative studies of the effect of screening on both quality of life and hard outcomes.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Prevention, Vascular Medicine, Aortic Surgery, Cardiac Surgery and Arrhythmias, Interventions and Imaging, Interventions and Vascular Medicine

Keywords: Aortic Aneurysm, Abdominal, Cardiac Surgical Procedures, Cost-Benefit Analysis, Diagnostic Imaging, National Health Programs, Outcome Assessment (Health Care), Primary Prevention, Quality of Life, Quality-Adjusted Life Years, Vascular Diseases, Women


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