Patient Safety Indicators Used to Compare Safety of EVAR and Open AAA Repair

July 9, 2014—A study evaluated the comparative safety of endovascular aneurysm repair (EVAR) versus open aneurysm repair (OAR) of abdominal aortic aneurysms (AAAs) by measuring patient safety indicators (PSIs) associated with each procedure over time. PSIs were established by the US Agency for Healthcare Research and Quality in 2003 to monitor preventable adverse events during hospitalizations. The study by John Rose, MD, et al was published online ahead of print in the Journal of the American Medical Association (JAMA): Surgery.

The investigators concluded that PSIs can be used to monitor the comparative safety of emerging surgical technologies. The study found that EVAR was safer than OAR and that the adoption of minimally invasive technology can improve safety among surgical admissions.

As summarized in JAMA: Surgery, the study’s main measurements were PSIs and mortality rates. The investigators used the Nationwide Inpatient Sample (2003–2010) to extract cases of AAA repair. PSIs were calculated using US Agency for Healthcare Research and Quality software (Win QI, version 4.4). Unadjusted analysis included year, age, sex, race/ethnicity, comorbidities, rupture status, hospital teaching status, and emergency status. Multivariable analysis was stratified by year for any PSI in EVAR versus OAR. Postoperative mortality was analyzed to control for the overall safety. 

The investigators documented 43,385 EVARs with 1,289 (3%) associated PSIs and 27,561 OARs with 3,094 (11.2%) associated PSIs. Compared with those undergoing OAR, patients undergoing EVAR were more likely to be male, older, and of white race/ethnicity; have a lower Charlson Comorbidity Index; and seek care at teaching hospitals (P < .001 for all). Patients were less likely to have a PSI after EVAR than after OAR. 

Overall, multivariable analysis showed that EVAR was associated with a 42.1% decrease in the risk-adjusted odds of any PSI compared with OAR (odds ratio, 0.58; 95% CI, 0.5–0.65). Stratified by year, the risk-adjusted odds of any PSI after EVAR were comparatively less likely than after OAR every year except for 2007, and the odds of death were comparatively less every year. The annual percentage of PSIs among all aortic repairs decreased from 7.4% in 2003 to 4.4% in 2010, while the proportion of total repairs that were EVARs increased from 41.1% in 2003 to 75.3% in 2010, reported the investigators in JAMA: Surgery.