Abstract 866: Screening for Abdominal Aortic Aneurysms - Benefit and Cost Effectiveness Analysis Based on 14 Years Results From a Single-centre Randomised Controlled Trial
Background: Long-term benefits and cost-effectiveness for abdominal aortic aneurysm (AAA) screening are uncertain.
Objective: To estimate the benefits, in terms of AAA-related and all-cause mortality, and cost-effectiveness of ultrasonography screening for AAA.Design: Randomised trial. Setting: Single centre in Denmark. Patients: Population-based sample of 12,639 men aged 64 –73 years. Intervention: Patients with an AAA detected at screening had surveillance and referred for operative evaluation of AAA > 5 cm.
Methods: Average survival time and AAA related health care costs were compared based on the individuals in the sample. Mortality data and incidence of AAA related surgery were obtained from national databases. Costs for screening and surveillance was based on the actual cost of the screening programme and was estimated at 28€ per screened patient. Average cost related to elective surgery, acute surgery without rupture and acute surgery with rupture was estimated at 14,530, 25,150 and 31,750€ (2007 price levels) based on a detailed costing study. Mortality and surgery rates were estimated per 100.000 and hazard rates estimated by Cox regression. In the cost-effectiveness analysis average gains in life-years and quality-adjusted life years (QALY) were compared with average costs.
Results: The age-adjusted hazard ratio was 0.35 ((95% CI: 0.20; 0.58); p<0.001) for AAA-related mortality in the group invited for screening. In terms of all-cause mortality, the observed hazard ratio was 0.98 (0.93–1.03); p=0.36). After 14 years follow-up the average incremental gain in life years were and QALY were estimated at 0.09 life years and 0.08 QALY. The incremental cost per life year gained was estimated at 148€ (Bootstrap 95% CI, −4059;3838), and 222€ (CI, −3544;4886) per quality of life adjusted life-year gained. In a subgroup analysis of men aged 65, the hazard rate for AAA-related mortality was 0.36 (p=0.03). For this sub-group the incremental cost effectiveness rate was estimated at − 416€ (CI −17684;19084) per life year gained and 59€ (CI −23573;28807) per QALY gained.
Conclusions: The early mortality benefit of screening for AAA is maintained in the longer term and the cost-effectiveness of screening improves over time.