This study states that Abdominal aortic aneurysm (AAA) can occur in patients who are ineligible for routine ultrasound screening. A simple AAA risk score was derived and compared to current guidelines used for ultrasound screening of AAA. UK Biobank participants without previous AAA were split into a derivation cohort (n=401,820, 54.6% women, mean age 56.4 years, 95.5% white race) and validation cohort (n=83,816). Incident AAA was defined as first hospital inpatient diagnosis of AAA, death from AAA, or an AAA-related surgical procedure. A multivariable Cox model was developed in the derivation cohort into an AAA risk score that did not require blood biomarkers. To illustrate the sensitivity and specificity of the risk score for AAA, a theoretical threshold to refer patients for ultrasound at 0.25% 10-year risk was modelled. Discrimination of the risk score was compared to a model of US Preventive Services Task Force (USPSTF) AAA screening guidelines. In the derivation cohort there were 1,570 (0.40%) cases of AAA over a median 11.3 years of follow-up. 

Reference link- https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.120.053022