Updated US Preventive Services Task Force Recommendations for Abdominal Aortic Aneurysm-Are We Really Up To Date?

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

OBJECTIVE

In 2014, in addition to male smokers aged 65-75, the U.S. Preventive Services Task Force (USPSTF) recommended abdominal aortic aneurysm (AAA) screening for male never-smokers aged 65-75 with cardiovascular risk factors (Grade C). The USPSTF evolved from a negative to neutral position on screening for female smokers aged 65-75 (Grade I). We sought to determine whether 2014 guidelines resulted in more AAA repairs in these populations.

METHODS

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 (intervention group) and 76-85 (control). The second model compared repair numbers between female smokers aged 65-75 (intervention group) and 76-85 (control).

RESULTS

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 compared with 76-85 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).

CONCLUSIONS

The USPSTF 2014 AAA guidelines were associated with modestly increased repairs in male never-smokers aged 65-75 only on Medicare. There was no impact among female smokers. Higher-grade recommendations and improved guideline adherence may be requisites for change.

Costs of abdominal aortic aneurysm care at a regional Veterans Affairs medical center with the implementation of an abdominal aortic aneurysm screening program

BACKGROUND

Abdominal aortic aneurysm (AAA) screening has demonstrated to be cost-effective in reducing AAA-related morbidity and all-cause mortality. However, the downstream care costs of an implemented AAA screening in clinical practice have not been reported. The purpose of this study is to determine direct regional Department of Veterans Affairs (VA) costs in implementing and sustaining an AAA screening program over a 10-year period.

METHODS

A cost data analysis (adjusted to 2021 U.S. dollars) of an AAA screening program was conducted from 2007 to 2016, where 19,649 veteran patients aged 65-75 with a smoking history were screened at a regional VA medical center. A decision support system tracked direct and indirect encounter costs from Medicare billing codes associated with AAA care. Costs from a patient's initial screening, follow-up imaging, to AAA repair or at the end of the analysis period, March 31, 2021, were recorded. Costs for AAA repairs outside the VA system were also tracked.

RESULTS

A total of 1,183 patients screened were identified with an AAA ≥3.0 cm without history of repair. Estimated screening costs were $2.8 million or $280,000 annually ($143/screening) in the care of 19,649 screened patients. There were 221 patients who required repair (143 repairs in VA, 78 repairs outside VA). The average cost of elective endovascular repair was $43,021 and that of open repair was $49,871. The total costs for all elective repairs were $9,692,591. Screening, implementation, maintenance, and surgical repair cost involved in the management of patients with AAA disease was $13.7 million, with $10,686 per life-year lived after repair (5.8 ± 3.5 mean life-years) and $490 per life-year lived after screening (6.9 ± 3.5 mean life-years) for all patients screened. There were 13 deaths of unknown causes and one patient with a ruptured AAA that required emergency repair at a cost of $124,392.

CONCLUSIONS

Despite known limitations, the implementation of an AAA ultrasound screening program is feasible, cost-effective, and a worthwhile endeavor.