Jian Liang Tan (Crozer-Chester Medical Center), Jugeet Kanwal (Crozer-Chester Medical Center), Joanne Connaughton (Crozer-Chester Medical Center)
Abdominal aortic aneurysm (AAA), defined as aortic diameter ≥ 3.0 cm, affects an estimated 1.5% to 1.7% of men aged 65 or older. It was estimated that a ruptured AAA has a mortality rate of 75% – 90%.1 Screening for AAA with an abdominal ultrasound is relatively cost-effective.2
The aims of this study are to determine patterns of AAA screening in an internal medicine resident-run clinic and to identify resident physician knowledge associated with AAA screening.
This is a retrospective chart review study of a total of 130 male patients, between the age of 65 to 75, who had visited our clinic over the period from July 2007 to July 2017. Inclusion criteria: Male patients only, age 65 to 75 years. Exclusion criteria: Age <65 or >75 years, all female patients, inactive status for ≥2 years or deceased. The data were collected and analyzed for the rates of the AAA screening in eligible patients, the rates of AAA screening ordered intentionally with abdominal ultrasound and incidentally with other imaging modality (CAT or MRI scan of the abdomen), and the rates of redundant screening. A survey consisting of 8 questions was distributed to 23 Internal Medicine resident physicians. We focused on assessing their understanding of AAA screening in accordance with the U.S. Preventive Services Task Force (USPSTF) recommendations.
Out of 130 patients, 112 (86.2%) patients met the study criteria. Of these 112 patients, 39.3% had never smoked, 42% were former smokers and 18.7% were active smokers. According to the USPSTF grade B recommendation (male patient, aged between 65-75, who has ever smoked), a total of 68 patients were eligible for AAA screening. Of those who were eligible for screening only 36.7% (25/68) were screened for AAA. Of those who underwent screening, 64% (16/25) had AAA screening done by abdominal ultrasound and another 36% (9/25) had other imaging modality done for AAA screening. 36% (9/25) did not have their AAA screening result available in the outpatient EMR. In addition, 12.5% (2/16) patients, who have had other imaging modality performed, had unnecessary AAA screening with abdominal ultrasound. Of the 23 completed resident surveys, 22 of them were aware of the USPSTF guidelines on AAA screening. However, only 10 out of 23 residents had demonstrated sufficient familiarity with the AAA screening in accordance with the USPSTF recommendations.
In our study, we found that the AAA screening remained as an underutilized screening test in our clinic. The lack of familiarity with the USPSTF recommendation on AAA screening among the residents might have been the main reason of low AAA screening rate in our clinic.
Implications for the Patient
Appropriate screening for AAA in high-risk population provided a moderate benefit in decreasing AAA-related mortality with an absolute risk reduction of 0.14%. Hence, a separate message was sent to our resident physicians as a reminder to screen appropriate high-risk patient with ultrasound for AAA.