Surveillance outcomes of small abdominal aortic aneurysms identified from a large screening program.

ABSTRACT

OBJECTIVE: Surveillance of patients identified with small abdominal aortic aneurysm (AAA) from an AAA screening program poses a challenge for health systems because of numerous patient follow-ups. This study evaluates the surveillance outcomes of patients identified with small AAA from a large screening program. METHODS: A retrospective chart review of all patients screened for small AAA (3.0-5.4 cm) from 2007 to 2011 was conducted. Patients with small AAA and no previous history of repair were tracked for follow-up using the 2013 RESCAN follow-up guidelines according to aortic diameter (3.0-3.9 cm, 3 years; 4.0-4.4 cm, 2 years; 4.5-5.4 cm, 1 year). Socioeconomic factors that may influence the follow-up rate and all-cause mortality after screening, including marital status, distance to hospital from residence, estimated household income, and employment disability status, were also evaluated. RESULTS: A total of 568 patients (mean ± standard deviation, 73.4 ± 7.2 years old) with small AAA (3.6 ± 0.6 cm) were analyzed. Patient follow-up rate was 65.1% (n = 370 of 568). Reasons for follow-up failure were lack of the physician's ordering a scan (n = 139; 70.2%), delayed ordering of scans (n = 36; 18.2%), patient no-show (n = 18; 9.1%), or patient death before follow-up (n = 5; 2.5%). Of all patient-specific factors, patients with smaller diameters were unlikely to achieve follow-up scans (P < .001). A significantly higher risk of all-cause mortality was found for patients with no ultrasound follow-up scan (hazard ratio [HR], 0.369; P < .001), assisted living (HR, 0.381; P < .001), older age (HR, 1.04; P = .001), and lower household incomes (HR, 0.989; P = .01). CONCLUSIONS: The follow-up rate of patients with small AAA was poor at 65.1%. The data indicate that socioeconomic factors do not significantly affect follow-up success. Therefore, physician ordering of scans may exert the greatest influence on follow-up rates in patients with small AAA. Automatic ordering of follow-up scans for patients with small AAAs is proposed to improve follow-up rates.