Screening for abdominal aortic aneurysm.
BACKGROUND
Abdominal aortic aneurysm (AAA) is found in 5% to 10% of men aged 65 to 79 years. The major complication is rupture which presents as a surgical emergency. The mortality after rupture is high, 80% for patients reaching hospital and 50% for those undergoing surgery for emergency repair. Currently elective surgical repair is recommended for aneurysms discovered to be larger than 5.5 cm to prevent rupture. There is interest in population screening to detect, monitor and repair abdominal aortic aneurysms before rupture.


OBJECTIVE
To determine the effects of screening asymptomatic individuals for AAA on mortality, subsequent treatment, quality of life and cost effectiveness of screening.


METHODS
The Cochrane Peripheral Vascular Diseases Group searched their Trials Register (last searched 26 January 2007) and CENTRAL (last searched Issue 1, 2007).


METHODS
Randomised controlled trials of population screening for AAA.


METHODS
Two authors independently assessed trials and extracted data.


RESULTS
Four studies involving 127,891 men and 9,342 women were included in this review. Only one study included women. 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 (men, odds ratio (OR) 0.95; 95% Confidence interval (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.


CONCLUSIONS
There is evidence of a significant reduction in mortality from AAA in men aged 65 to 79 years who undergo ultrasound screening. There is insufficient evidence to demonstrate benefit in women. The cost effectiveness may be acceptable, but needs further expert analysis. These findings need careful consideration in judging whether a co-ordinated population-based screening programme should be introduced.
Cosford
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Victoria House, East of England Strategic Health Authority, Capital Park, Fulbourn, Cambridge, UK, CB1 5XB. Paul.Cosford@eoe.nhs.uk
Leng
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GC
D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis* / Q000401:mortality / Q000601:surgery; D003362:Cost-Benefit Analysis; D005260:Female; D006801:Humans; D008017:Life Expectancy; D008297:Male; D008403:Mass Screening / Q000191:economics; D016032:Randomized Controlled Trials as Topic; D012737:Sex Factors