From family medical practices 15775 men and women of men). Aortic surgery was offered to the screened group aged 65-80 years were identified and randomized into two if certain criteria were met and no patient died from groups: one group was invited for ultrasonographic rupture who was fit for operation and accepted elective screening for abdominal aortic aneurysm (AAA), and the treatment. The incidence of rupture was reduced by 55 other acted as age-and sex-matched controls. Of the 7887 per cent in men in the group invited for screening, invited for screening 5394 (68.4 per cent) accepted. AAA compared with controls. The incidence of rupture in was detected in 218 (4.0 per cent overall and 7-6 per cent women was low in both groups. Patients and methodsMen and women aged 65-80 years were identified for each general practice in this district from a combination of the practice register and Family Health Service lists. The patients in each practice were then randomized by computer to 'control' and 'screening' groups. Patients randomized to screening were invited for abdominal ultrasonographic scanning by letter from their family practice; one reminder was sent if there was no reply. Maximum aortic diameter in the anteroposterior and transverse planes was measured as previously described". A diameter of 3 cm or more was considered aneurysmal. Patients with an aneurysm of 3.0-4.4 cm diameter were rescanned annually and those with an aneurysm of 45-59 cm diameter were rescanned at intervals of 3 months. This protocol was continued for the duration of the study to February 1994 or until the patient either died, underwent surgical intervention or declined further followup. The criteria for considering surgical repair were applied prospectively: an aortic diameter of 6 cm or more, an increase of diameter of 1 cm or more per year, or the development of symptoms attributable to the aneurysm. Abnormal scans and batches of normal scans were reviewed by a consultant radiologist for quality control. Patients were assessed in outpatient clinics at their third scan or if an abnormality was detected; a further confirmatory scan was Paper accepted 3 March 1995 1066 performed by the consultant vascular surgeon at this visit. Patients who fulfilled the criteria for surgery were assessed and elective aneurysm repair planned if they were deemed fit and consented to operation. If patients were unfit or declined surgery, ultrasonographic surveillance was continued. Criteria for fitness for surgery were based on those of Bernstein and Chan".Mortality data were obtained weekly from the Registrar of Births and Deaths in Chichester district before coding was undertaken, and those labelled as aortic aneurysm were checked by a clinician. The causes of death for the study population were noted, including ruptured AAA. Details of those dying outside the district but who lived locally were included. Details of operative mortality and morbidity were obtained from a prospective study started in 19814. Results Population screened and acceptance rate...

Screening women for AAA is neither clinically indicated nor economically viable.

Objectives To assess whether the mortality benefit from screening men aged 65-74 for abdominal aortic aneurysm decreases over time, and to estimate the long term cost effectiveness of screening. Design Randomised trial with 10 years of follow-up. Setting Four centres in the UK. Screening and surveillance was delivered mainly in primary care settings, with followup and surgery offered in hospitals. Participants Population based sample of 67 770 men aged 65-74. Interventions Participants were individually allocated to invitation to ultrasound screening (invited group) or to a control group not offered screening. Patients with an abdominal aortic aneurysm detected at screening underwent surveillance and were offered surgery if they met predefined criteria. Main outcome measures Mortality and costs related to abdominal aortic aneurysm, and cost per life year gained. Results Over 10 years 155 deaths related to abdominal aortic aneurysm (absolute risk 0.46%) occurred in the invited group and 296 (0.87%) in the control group (relative risk reduction 48%, 95% confidence interval 37% to

Background:The long-term effects of abdominal aortic aneurysm (AAA) screening were investigated in extended follow-up from the UK Multicentre Aneurysm Screening Study (MASS) randomized trial.Methods:A population-based sample of men aged 65–74 years were randomized individually to invitation to ultrasound screening (invited group) or to a control group not offered screening. Patients with an AAA (3·0 cm or larger) detected at screening underwent surveillance and were offered surgery after predefined criteria had been met. Cause-specific mortality data were analysed using Cox regression.Results:Some 67 770 men were enrolled in the study. Over 13 years, there were 224 AAA-related deaths in the invited group and 381 in the control group, a 42 (95 per cent confidence interval 31 to 51) per cent reduction. There was no evidence of effect on other causes of death, but there was an overall reduction in all-cause mortality of 3 (1 to 5) per cent. The degree of benefit seen in earlier years of follow-up was slightly diminished by the occurrence of AAA ruptures in those with an aorta originally screened normal. About half of these ruptures had a baseline aortic diameter in the range 2·5–2·9 cm. It was estimated that 216 men need to be invited to screening to save one death over the next 13 years.Conclusion:Screening resulted in a reduction in all-cause mortality, and the benefit in AAA-related mortality continued to accumulate throughout follow-up. Registration number: ISRCTN37381646 (http://www.controlled-trials.com).

Male sex, smoking and hypertension are strong risk factors for the development of AAA. In this study hypertension did not significantly increase the growth rate of existing aneurysms. Smoking remains the most important avoidable risk factor for AAA. The analyses presented here suggest that selection for screening, other than by age and sex, is not worthwhile.