BACKGROUND: The aim was to estimate long-term mortality benefits and cost-effectiveness of screening for abdominal aortic aneurysm (AAA) in men aged 64-73 years.
METHODS: All men aged 64-73 years living in Viborg County were randomized to be controls (n = 6306) or invited for abdominal ultrasonography at a regional hospital (n = 6333). Mortality and AAA-related interventions were recorded in national databases. The cost of initial screening was based on actual costs of the programme. Incremental cost-effectiveness ratios (ICERs) were calculated on gains in life years and Quality Adjusted Life Years (QALY). Discounting (3 per cent) was applied to both costs and effects, and all costs were adjusted to euros at 2007 prices.
RESULTS: The relative risk reduction of the screening programme in AAA-related mortality was 66 per cent (hazard ratio 0.34, 95 per cent confidence interval (c.i.) 0.20 to 0.57). The corresponding risk reduction in all-cause mortality was 2 per cent (hazard ratio 0.98, 95 per cent c.i. 0.93 to 1.03). The ICER was estimated at euro157 (-3292 to 4401) per life year gained and euro179 (-4083 to 4682) per QALY gained. Screening was found to be cost effective at a probability above 0.97 for a willingness-to-pay threshold of only euro5000. One-way sensitivity analysis demonstrated that this result was robust to various alternative assumptions, as the probability did not drop below 0.90 for any scenario.
CONCLUSION: The mortality benefit of screening for AAA in men aged 64-73 years was maintained in the longer term and screening was cost effective.
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 follow-up 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 57%). The degree of benefit seen in earlier years of follow-up was maintained in later years. Based on the 10 year trial data, the incremental cost per man invited to screening was £100 (95% confidence interval £82 to £118), leading to an incremental cost effectiveness ratio of £7600 (£5100 to £13 000) per life year gained. However, the incidence of ruptured abdominal aortic aneurysms in those originally screened as normal increased noticeably after eight years. Conclusions: The mortality benefit of screening men aged 65-74 for abdominal aortic aneurysm is maintained up to 10 years and cost effectiveness becomes more favourable over time. To maximise the benefit from a screening programme, emphasis should be placed on achieving a high initial rate of attendance and good adherence to clinical follow-up, preventing delays in undertaking surgery, and maintaining a low operative mortality after elective surgery. On the basis of current evidence, rescreening of those originally screened as normal is not justified. Trial registration: Current Controlled Trials ISRCTN37381646.
BACKGROUND: Long-term benefits of screening for abdominal aortic aneurysm (AAA) are uncertain. These are the final results of a randomized controlled screening trial for AAA in men, updating those reported previously. Benefit and compliance over a median 15-year interval were examined.
METHODS: One group of men were invited for ultrasonographic AAA screening, and another group, who received standard care, acted as controls. A total of 6040 men aged 65-80 years were randomized to one of the two groups. Outcome was monitored in terms of AAA-related events (surgery or death).
RESULTS: In the group invited for screening, AAA-related mortality was reduced by 11 per cent (from 1.8 to 1.6 per cent, hazard ratio 0.89) over the follow-up interval. Screening detected an AAA in 170 patients; 17 of these died from an AAA-related cause, seven of which might have been preventable. The incidence of AAA rupture after an initially normal scan increased after 10 years of follow-up, but was still low overall (0.56 per 1000 person-years).
CONCLUSION: Screening with a single ultrasonography scan still conferred a benefit at 15 years, although the results were not significant for this population size. Fewer than half of the AAA-related deaths in those screened positive could be prevented.
REGISTRATION NUMBER: ISRCTN 00079388 (http://www.controlled-trials.com).
The aim was to estimate long-term mortality benefits and cost-effectiveness of screening for abdominal aortic aneurysm (AAA) in men aged 64-73 years.
METHODS:
All men aged 64-73 years living in Viborg County were randomized to be controls (n = 6306) or invited for abdominal ultrasonography at a regional hospital (n = 6333). Mortality and AAA-related interventions were recorded in national databases. The cost of initial screening was based on actual costs of the programme. Incremental cost-effectiveness ratios (ICERs) were calculated on gains in life years and Quality Adjusted Life Years (QALY). Discounting (3 per cent) was applied to both costs and effects, and all costs were adjusted to euros at 2007 prices.
RESULTS:
The relative risk reduction of the screening programme in AAA-related mortality was 66 per cent (hazard ratio 0.34, 95 per cent confidence interval (c.i.) 0.20 to 0.57). The corresponding risk reduction in all-cause mortality was 2 per cent (hazard ratio 0.98, 95 per cent c.i. 0.93 to 1.03). The ICER was estimated at euro157 (-3292 to 4401) per life year gained and euro179 (-4083 to 4682) per QALY gained. Screening was found to be cost effective at a probability above 0.97 for a willingness-to-pay threshold of only euro5000. One-way sensitivity analysis demonstrated that this result was robust to various alternative assumptions, as the probability did not drop below 0.90 for any scenario.
CONCLUSION:
The mortality benefit of screening for AAA in men aged 64-73 years was maintained in the longer term and screening was cost effective.
