Cost-effectiveness of targeted screening for abdominal aortic aneurysm in siblings.

Background: Population screening for abdominal aortic aneurysm (AAA) in 65­year­old men has been shown to be cost­effective. A risk group with higher prevalence is siblings of patients with an AAA. This health economic model­based study evaluated the potential cost­effectiveness of targeted AAA screening of siblings. Methods: A Markov model validated against other screening programmes was used. Two methods of identifying siblings were analysed: direct questioning of patients with an AAA (method A), and employing a national multigeneration register (method B). The prevalence was based on observed ultrasound data on AAAs in siblings. Additional parameters were extracted from RCTs, vascular registers, literature and ongoing screening. The outcome was cost­effectiveness, probability of cost­effectiveness at different willingness­to­pay (WTP) thresholds, reduction in AAA death, quality­adjusted life­years (QALYs) gained and total costs on a national scale. Results: Methods A and B were estimated to reduce mortality from AAA, at incremental cost­effectiveness ratios of €7800 (95 per cent c.i. 4627 to 12 982) and €7666 (5000 to 13 373) per QALY respectively. The probability of cost­effectiveness was 99 per cent at a WTP of €23 000. The absolute risk reduction in AAA deaths was five per 1000 invited. QALYs gained were 27 per 1000 invited. In a population of ten million, methods A and B were estimated to prevent 12 and 17 AAA deaths, among 2418 and 3572 siblings identified annually, at total costs of €499 500 and €728 700 respectively. Conclusion: The analysis indicates that aneurysm­related mortality could be decreased cost­effectively by applying a targeted screening method for siblings of patients with an AAA.

Five Year Natural History of Screening Detected Sub-Aneurysms and Abdominal Aortic Aneurysms in 70 Year Old Women and Systematic Review of Repair Rate in Women.

OBJECTIVE: The aim of this study was to report on the natural history of a population based cohort of 70 year old women with screening detected dilated aortas, and to systematically review publications reporting the rate of intact infrarenal aneurysm repair in women. MATERIAL AND METHODS: In a previous study, 5140 (74%) of 6925 invited women attended an ultrasound (US) examination of the abdominal aorta at age 70 years. All 52 women with screening detected sub-aneurysms (SA, diameter 25-29 mm) and abdominal aortic aneurysms (AAA, diameter ≥30 mm), were followed for 5 years with US. Infrarenal aortic diameters, AAA repair, all-cause and AAA specific mortality, and risk factors were recorded. In addition, a systematic review was conducted of the rate of intact infrarenal aneurysm repair in women. RESULTS: A total of 33 (0.6%) women had a SA at the age of 70; two (6%) declined follow-up, five (15%) had died, and 26 were re-examined after 5 years follow-up at age 75. Twelve of 26 (46%) had progressed to AAAs, where one was directly qualified for surgery. Smoking (p = .010) and aortic diameter (p = .040) were associated with progression to AAA. A total of 19 (0.4%) women had an AAA at age 70; two (11%) had died, six (32%) had been electively repaired with no 30 day mortality, and 11 (58%) had an AAA still under surveillance after 5 years follow-up at age 75 years. In the systematic search four studies with heterogeneous cohorts were identified and data on natural history were extracted and reviewed. CONCLUSION: Screening detected AAAs and sub-aneurysms are clinically relevant in women. Within 5 years of detection a high proportion of AAAs require elective surgery, and a high proportion of sub-aneurysms progress to AAAs. Consequently, surveillance of sub-aneurysms in women with reasonable life expectancy can be considered. Publications on repair rate in women with intact AAAs are scarce and heterogeneous.

Update on screening for abdominal aortic aneurysm: a topical review.

OBJECTIVES: Serving as the basis for implementation of several national AAA screening programmes, four large randomised controlled trials provided evidence of a reduction in AAA mortality by ultrasound-based screening among elderly men. Recently, reports of falling AAA prevalence and mortality unrelated to AAA screening have emerged, coinciding with major additional epidemiological changes in the population, as well as improvements in AAA repair. These recent changes may individually, and in concert, affect the rationality of AAA screening. The aim of this paper was to present an up-to-date review of AAA-screening within the context of a rapidly changing AAA epidemiology. METHODS: Topical review of the literature focusing mainly on randomised controlled trials, meta-analyses, and contemporary observational AAA-screening studies. CONCLUSIONS: Summarising RCT results and recent studies; contemporary one-time screening of men for AAA appears highly cost-effective, and seems to remain an effective preventive health-measure. However, several issues regarding screening need to be addressed: most importantly; the current degree of incidental detection of AAAs, the threshold diameter for follow-up, targeted screening in risk groups, and the possible need for re-screening in an elderly population with ever increasing longevity.

Screening for abdominal aortic aneurysm in 65-year-old men remains cost-effective with contemporary epidemiology and management.

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.

Editor's choice: five-year outcomes in men screened for abdominal aortic aneurysm at 65 years of age: a population-based cohort study.

OBJECTIVE: Acquiring contemporary data on prevalence and natural history of abdominal aortic aneurysms (AAA) is essential in the effort to optimise modern screening programmes. The primary aim of this study was to determine the fate of a 65-year-old male population 5 years following an invitation to an aortic ultrasound (US) examination. METHODS: In this population-based cohort-study, men were invited to US examination at age 65, and were re-invited at age 70. Mortality, AAA repair, and risk factors were recorded. An AAA was defined as a diameter ≥30 mm, and a sub-aneurysmal aorta as 25-29 mm. RESULTS: In 2006-2007, 3,268 65-year-old men were invited, and 2,736 (83.7%) were examined. After 5 years, 24 had completed AAA repair (6 died within 0-4 years), an additional 239 had died, and 194 had moved. Thus, 2,811 70-year-old men were re-invited, and 2,247 (79.9%) were examined. The AAA prevalence increased from 1.5% at 65 to 2.4% (95% CI: 1.8 to 3.0) at 70, and of sub-aneurysmal aortas from 1.7% at 65 to 2.6% (2.0 to 3.3), at 70. Of 2,041 with <25 mm at 65, 0.7% had an AAA at 70. Of 40 with a sub-aneurysmal aorta at 65, 52.5% progressed to AAA at 70. In a Cox regression analysis, sub-aneurysmal aorta at 65 (hazard ratio [HR] 59.78) and smoking (HR 2.78) were independent risk factors for AAA formation. Among 44 with AAA at 65, 22 completed AAA repair with no 30-day mortality. CONCLUSION: AAA screening in a contemporary setting was safe at 5 years, with a single AAA rupture observed among non-attenders. Men with a screening detected AAA had a high repair rate and high non-AAA related mortality. AAA-formation was common among men with sub-aneurysmal dilatation, indicating a possible need for surveillance of this group.

Current prevalence of abdominal aortic aneurysm in 70-year-old women.

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.

Screening for abdominal aortic aneurysm--areas where information is still inadequate.

Abdominal aortic aneurysm (AAA) fulfils the criteria for a disease suitable for screening. However, important aspects need to be further analysed; the optimal age of the male population considered for screening has not yet been established, and whether women or specific high risk groups would benefit from screening has not been sufficiently evaluated. The impact of the current shift toward a high proportion of AAA repair done with endovascular technique and the long-term effect on QoL are additional issues that have not been adequately studied. Furthermore, therapeutic options for small AAA as well as secondary prevention programmes have to be developed.

Thoracic and thoracoabdominal aortic aneurysm and dissection: an investigation based on autopsy.

The city of Malmö (population approximately 230,000) has a fairly stable urban population and a high autopsy rate (83 per cent of all deaths). Autopsy records for the period from 1958 to 1985 were scrutinized and three groups of patients were defined: those with asymptomatic thoracic aortic aneurysm (TAA), those with rupture of the thoracic aorta, and those with dissection. The findings were used to calculate prevalence and incidence according to age and sex. Asymptomatic TAA was found in 205 patients (109 men). There was a predominance of men in higher age groups and about 5 per cent of the lesions were thoracoabdominal. Rupture of the thoracic aorta was the cause of death in 63 patients; no age difference between the sexes was observed. Death as a result of dissection occurred in 216 patients, women dying on average 7 years later than men. The incidence of rupture was 0.9 per 100,000 for men and 1.0 per 100,000 for women; the incidence of dissection was 3.2 per 100,000 for both sexes. Prevalence and incidence of fatal complications of TAA are low; this may influence decisions about where these patients should be treated.