To assess the cost effectiveness of ultrasound screening for abdominal aortic aneurysms.
Primary analysis: four year cost effectiveness analysis based directly on results from a randomised controlled trial in which patients were individually allocated to invitation to ultrasound screening (intervention) or to a control group not offered screening. Secondary analysis: projection of the data, based on conservative assumptions, to indicate likely cost effectiveness at 10 years.
Four centres in the United Kingdom. Screening delivered in primary care settings with follow up and surgery offered in the main hospitals
Population based sample of 67800 men aged 65-74 years.
Main outcome measures
Mortality from and costs (screening, follow up, elective and emergency surgery) related to abdominal aortic aneurysm; cost per life year gained.
Over four years there were 47 fewer deaths related to abdominal aortic aneurysms in the screening group than in the control group, but the additional costs incurred were £2.2m. After adjustment for censoring and discounted at 6% the mean additional cost of the screening programme was £63.39 ($97.77, €100.48) (95% confidence interval £53.31 to £73.48) per patient. The hazard ratio for abdominal aortic aneurysm was 0.58 (0.42 to 0.78). Over four years the mean incremental cost effectiveness ratio for screening was £28400 (£15000 to £146000) per life year gained, equivalent to about £36000 per quality adjusted life year. After 10 years this figure is estimated to fall to around £8000 per life year gained.
Even at four years the cost effectiveness of screening for abdominal aortic aneurysms is at the margin of acceptability according to current NHS thresholds. Over a longer period the cost effectiveness will improve substantially, the predicted ratio at 10 years falling to around a quarter of the four year figure.
What is already known on this topic
Small trials have suggested that an ultrasound screening programme to detect abdominal aortic aneurysms in older men may be effective
There is uncertainty about the cost effectiveness of routine screening, with widely varying estimates
What this study adds
A cost effectiveness analysis of data from a large randomised trial with follow up over four years showed 47 fewer deaths and additional costs of £2.2m in the group invited to screening
The adjusted net cost per patient was £63.39 and per life year gained was £28400
The projected cost per life year gained after 10 years was £8000, which is substantially lower than the perceived NHS threshold value