A recent study in The Lancet investigated whether the abdominal aortic aneurysm screening program in Sweden is associated with reduced morbidity and mortality.
Abdominal aortic aneurysm refers to the enlargement of the abdominal aorta to a size greater than 50% its original diameter. The enlargement of an individual’s aorta can weaken the vessel’s wall, increasing the risk of aortic rupture and death.
In the 1980s and 1990s, studies found that systematic screening for abdominal aortic aneurysm (AAA) was an effective method of reducing the risk of AAA-associated morbidity and mortality. More recently, however, studies have questioned these findings, and several suggest that nationwide screening for AAA is outdated and unnecessary.
A recent study led by Minna Johansson investigated whether the nation-wide AAA screening program for Swedish men over the age of 65 should be reconsidered. Their study included 25,265 participants that were invited for AAA screening and 106,087 participants that were not. They published their results in The Lancet.
For the study, they compared AAA incidence, mortality rate, and surgery rates between the two groups. The results demonstrated that 49 of every 10,000 men screened were over-diagnosed, while 19 of every 10,000 men screened underwent avoidable surgery.
Over-diagnosed patients include individuals that have had an AAA but will likely never experience any symptoms from their condition. Once diagnosed, however, these patients are more likely to undergo unnecessary and avoidable surgical procedures that can increase the risk of morbidity, mortality, and psychological harm.
Interestingly, the authors note that AAA-associated mortality in Sweden has steadily decreased by nearly 70% between 2000 and 2015. They argue this reduction in mortality rate can be attributed to a decline in smoking rates, rather than as a result of nation-wide AAA screening efforts.
Overall, the study suggests that the harms of screening for abdominal aortic aneurysm outweigh the benefits and that the implementation of nation-wide screening programs should be seriously reconsidered.
Written by Haisam Shah, BSc
(1) Mayor, S. (2018). Harms of screening for abdominal aortic aneurysm outweigh benefits, says study. BMJ.
(2) Johansson, M., Zahl, P. H., Siersma, V., Jørgensen, K. J., Marklund, B., & Brodersen, J. (2018). Benefits and harms of screening men for abdominal aortic aneurysm in Sweden: a registry-based cohort study. The Lancet, 391(10138), 2441-2447.