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BACKGROUND:

Screening elderly men with ultrasound is an established method to reduce mortality from ruptured abdominal aortic aneurysm (AAA; Evidence Level 1a). Such programs are being implemented and generally consist of a single scan at 65 years of age. We report the results from screening 65-year-old men for AAA in middle Sweden.

METHODS AND RESULTS:

All 65-year-old men (n=26,256), identified through the National Population Registry, were invited to an ultrasound examination. An AAA was defined as a maximum infrarenal aortic diameter of ≥30 mm. In total, 22 187 (85%) accepted, and 373 AAAs were detected (1.7%; 95% confidence interval, 1.5 to 1.9). With 127 previously known AAAs (repaired/under surveillance) included, the total prevalence of the disease in the population was 2.2% (95% confidence interval, 2.0 to 2.4). Self-reported smoking (odds ratio, 3.4; P<0.001), coronary artery disease (odds ratio, 2.0; P<0.001), and hypertension (odds ratio, 1.6; P=0.001) were independently associated with AAA in a multivariate logistic regression model. Thirteen percent of the entire population reported to be current smokers, one third of the frequency reported in the 1980s. The observed low prevalence of AAA was explained mainly by this change in smoking habits.

CONCLUSIONS:

On the basis of the observed reduced exposure to risk factors, lower-than-expected prevalence of AAA among 65-year-old men, unchanged AAA repair rate, and significantly improved longevity of the elderly population, the current generally agreed-on AAA screening model can be questioned. Important issues to address are the threshold diameter for follow-up, the possible need for rescreening at a higher age, and selective screening among smokers.

BACKGROUND:

Screening elderly men for abdominal aortic aneurysm (AAA) to reduce mortality from rupture is evidence-based. For women epidemiological data on AAA are scarce, and the evidence for screening is insufficient. The aim of this population-based study was to determine the current prevalence of AAA and risk factors among 70-year-old women.

METHODS:

All 70-year-old women identified through the National Population Registry in the two neighbouring counties of Uppsala and Dalarna were invited to a free ultrasound examination of the abdominal aorta. An AAA was defined as a maximum infrarenal aortic diameter of at least 30 mm.

RESULTS:

Of 6925 women invited, 5140 (74·2 per cent) accepted the invitation to be screened. Among these, 19 AAAs were detected (0·4 (95 per cent confidence interval (c.i.) 0·2 to 0·5) per cent). In the invited cohort 12 women (0·2 (0·1 to 0·3) per cent) had undergone previous AAA repair (11) or had a known AAA under surveillance (1). Thus, the total prevalence was estimated at 0·5 (0·4 to 0·7) per cent. Smoking was strongly associated with AAA; 18 (95 per cent) of 19 women with a screen-detected AAA had a history of smoking compared with 44·2 per cent of those with a normal aorta (odds ratio 20·29, 95 per cent c.i. 2·70 to 152·65). The prevalence of AAA was 0·03 (0 to 0·1) per cent among never smokers, 0·4 (0·2 to 0·8) per cent among former smokers and 2·1 (1·0 to 3·7) per cent among current smokers.

CONCLUSION:

Screening 70-year-old women who do not smoke is likely to be futile, thus ruling out population screening of women for AAA.

Objectives

The epidemiology and management of abdominal aortic aneurysms (AAA) has changed significantly, with lower prevalence, increased longevity of patients, increased use of endovascular aneurysm repair (EVAR), and improved outcome. The clinical and health economic effectiveness of one-time screening of 65-year-old men was assessed within this context.

Methods

One-time ultrasound screening of 65-year-old men (invited) versus no screening (control) was analysed in a Markov model. Data on the natural course of AAA (risk of repair and rupture) was based on randomised controlled trials. Screening detected AAA prevalence (1.7%), surgical management (50% EVAR), repair outcome, costs, and long-term survival were based on contemporary population-based data. Incremental cost-efficiency ratios (ICER), absolute and relative risk reduction for death from AAA (ARR, RRR), numbers needed to screen (NNS), and life-years gained were calculated. Annual discounting was 3.5%.

Results

In base case at 13-years follow-up the ICER was €14,706 per incremental quality-adjusted life-year (QALY); ARR was 15.1 per 10,000 invited, NNS was 530, and QALYs gained were 56.5 per 10,000 invited. RRR was 42% (from 0.36% in control to 0.21% in invited). In a lifetime analysis the ICER of screening decreased to €7,570/QALY. The parameters with highest impact on the cost-efficiency of screening in the sensitivity analysis were the prevalence of AAA (threshold value <0.5%) and degree of incidental detection in the control cohort.

Conclusions

In the face of recent changes in the management and epidemiology of AAA, screening men for AAA remains cost-effective and delivers significant clinical impact.