Population screening for abdominal aortic aneurysm: do the benefits outweigh the costs?

Abstract

To prevent the high mortality rate associated with ruptured abdominal aortic aneurysm (AAA), population screening at or soon after retirement age has been advocated, with elective operations being performed on patients with the appropriate indications. There is considerable pressure on some health authorities to fund such programmes even though there is substantial uncertainty about the consequent benefits. The ultrasound screening test is acceptable and accurate. Also, other health problems may be detected in the same screen. However, screening would lead to a questionable increase in surgery, as most patients with AAA die from other causes and not from a ruptured aneurysm. In addition, there is an elective operative mortality of around 5 per cent. Furthermore, as many of those who have a positive result on screening would never have known that they harbour an aneurysm, there is the possibility of unnecessary anxiety arising from the test. An economic analysis has been conducted for two identical, hypothetical cohorts of men using the best available data. One cohort was assumed to undergo screening and a number of men were indicated for immediate elective aneurysm repair or for follow-up, and surgery if their aneurysms become large. The other cohort was assumed not to be screened and would thereby face the possibility of rupture with its adverse outcome. The survival prospects of the two cohorts were calculated as life expectancies and in terms of life-years: the incremental life-years gained were compared with the incremental costs of the programme. Although there are considerable uncertainties in the analysis parameters, the base-line result and sensitivity analysis indicate that, on the basis of current knowledge, population screening should not be introduced.