Screening for AAA in women not very effective

Reference

Sweeting MJ, Masconi KL, Jones E, et al. Analysis of clinical benefit, harms, and cost-effectiveness of screening women for abdominal aortic aneurysm. Lancet 2018;392(10146):487-495.

Synopsis

These authors used a Markov decision analysis as the framework for conducting a cost-effectiveness analysis of screening women for AAA. A Markov analysis models how outcomes change over time. They adapted a previously validated analytic structure for screening men. They used data from published literature, hospital databases, and registries to gather such information as the frequency of prevalence of AAA at various ages, rupture rates by AAA size, surgical effectiveness, and so forth. Because these data may not reflect the "truth," the authors performed sensitivity analyses to determine thresholds at which the data would change the "final answer." The authors' synthesis suggests that screening women starting at age 65 years, using 3 cm as a diagnostic cutoff, and 5.5 cm as the cutoff for surgery would detect 0.31% of AAAs in the population (roughly 25% more than would otherwise have been detected), which would lead to an additional 452 surgeries per one million women. Approximately one-third of the screen-detected AAAs are overdiagnosed (actually present but will never cause problems) and 13% are overtreated. The authors estimated that over 30 years of screening, it would cost 30,000 pounds sterling (about US$38,000) for each quality-adjusted life year gained. One would have to invite nearly 4000 women to be screened to prevent one death. Altering their cutoffs to older than 70 years, diagnosis at 2.5 cm, and surgery at 5 cm was more cost-effective and only required 1800 invitations to prevent one death, but it had an overdiagnosis rate of 55%.