Screening for abdominal aortic aneurysm

Ultrasound screening for abdominal aortic aneurysm (AAA) is effective in reducing AAA related mortality and might possibly reduce all cause mortality in men aged 65 to 79 years. There is insufficient evidence to demonstrate benefit in women.

A Cochrane review included 4 studies with a total of 137 233 male and female subjects (only one study included women, n=9 342). Results for men and women were analysed separately. Three to five years after screening there was no significant difference in all-cause mortality between screened and unscreened groups for men or women (for men OR 0.95, 95% CI 0.85 to 1.07; for women OR 1.06, 95% CI 0.93 to 1.21). There was a significant decrease in mortality from AAA in men (OR 0.60, 95% CI 0.47 to 0.78), but not for women (OR 1.99, 95% CI 0.36 to 10.88). In this analysis mortality includes death from rupture and from emergency or elective surgery for aneurysm repair. There was also a decreased incidence of ruptured aneurysm in men (OR 0.45, 95% CI 0.21 to 0.99) but not in women (OR 1.49, 95% CI 0.25 to 8.94). There was a significant increase in surgery for AAA in men (OR 2.03, 95% CI 1.59 to 2.59). This was not reported in women. There were no data on life expectancy, complications of surgery or subjective quality of life. The MASS study has published a cost effectiveness analysis of the benefits of AAA screening. The study identified 47 fewer deaths over 4 years due to AAA, at an additional cost of £2.2 million. This equated to £28,400 per life year gained, and approximately £36,000 per QALY (Quality Adjusted Life Year). After 10 years this is estimated to fall to about £8,000 per life year gained. The Viborg trial identified outline hospital costs with an estimate of costs outside hospital. They derived a figure of DKK 7540 per life year saved (£1 = 12 DKK).

A systematic review including the same 4 studies as the Cochrane review was abstracted in DARE. Conclusions were similar. The review also evaluated repeated screening following negative results on ultrasonography. Overall, a single negative ultrasonography screen at age 65 years appeared to virtually exclude any future risk of AAA rupture or death.

A recent meta-analysis updates the Cochrane review with long-term follow-up data from the four studies. Pooled analysis showed a statistically significant reduction in AAA related mortality (risk difference –0.25%, 95% CI –0.46 to –0.004) and also in all cause mortality (risk difference –1.06%, 95% CI –1.81 to –0.31) with screening relative to control (random effects model).

The following decision support rules contain links to this evidence summary:

• Reminder of opportunistic abdominal aortic aneurysm screening

Ədəbiyyat

1. Cosford PA, Leng GC. Screening for abdominal aortic aneurysm. Cochrane Database Syst Rev 2007 Apr 18;(2):CD002945.
2. Fleming C, Whitlock EP, Beil TL, Lederle FA. Screening for abdominal aortic aneurysm: a best-evidence systematic review for the U.S. Preventive Services Task Force. Ann Intern Med 2005 Feb 1;142(3):203-11.
3. Takagi H, Tanabashi T, Kawai N, Umemoto T. Regarding "Screening for abdominal aortic aneurysm reduces both aneurysm-related and all-cause mortality". J Vasc Surg 2007 Dec;46(6):1311-2; author reply 1312.