The U.S. Preventive Services Task Force Abdominal Aortic Aneurysm Screening Guidelines Negligibly Impacted Repair Rates in Male Never-Smokers and Female Smokers

Abstract

In 2014, in addition to male smokers aged 65-75 years, the U.S. Preventive Services Task Force (USPSTF) recommended abdominal aortic aneurysm (AAA) screening for male never-smokers aged 65-75 years with cardiovascular risk factors (Grade C). The USPSTF evolved from a negative to neutral position on screening for female smokers aged 65-75 years (Grade I). We sought to determine whether 2014 guidelines resulted in more AAA repairs in these populations. We queried the Vascular Quality Initiative national database (2013-2018) for elective endovascular aortic repairs and open aortic repairs. We implemented difference-in-differences (DID) analysis, a causal inference technique that adjusts for secular time trends, to isolate changes in repair numbers due to the 2014 USPSTF guidelines. Our DID models compared changes in repair numbers in patient groups targeted by the USPSTF updates (intervention group) to those in unaffected, older patient groups (control), before and after 2014. The first model compared changes in repair numbers between male never-smokers aged 65-75 years (intervention group) and 76-85 years (control). The second model compared repair numbers between female smokers aged 65-75 years (intervention group) and 76-85 years (control). There was no significant change in male never-smokers (n=1,295) aged 65-75 (42%) vs. 76-85 (58%) undergoing AAA repairs after guideline updates, averaged over 4.5 years (+2.4 percentage points; 95% Confidence Interval [CI] -.56-5.26). However, when their primary insurer was Medicare, male never-smokers aged 65-75 years compared with 76-85 years underwent significantly more repairs over 4.5 years (+3.69 percentage points; 95% CI.16-7.22; representing a 10.4% relative increase from baseline in the proportion of male never-smokers on Medicare undergoing AAA repair). Comparing female smokers (n=2,312) aged 65-75 (54%) vs. 76-85 (46%), there was no significant change in repairs over 4.5 years (-.66 percentage points; 95% CI -4.57-3.26). The USPSTF 2014 AAA guidelines were associated with modestly increased repairs in male never-smokers aged 65-75 years only on Medicare. There was no impact among female smokers. Higher-grade recommendations and improved guideline adherence may be requisites for change.