Researchers at Cedars-Sinai Medical Center in Los Angeles, USA, have found that in contrast to other studies about regional discrepancies in the utilisation of some surgical procedures, the utilisation of endovascular aneurysm repair (EVAR) was not associated with physician capacity and distribution, socioeconomics or other non-medical factors. Details of this study were reported in the April issue of the Journal of Vascular Surgery, published by the Society for Vascular Surgery.
Bruce L Gewertz, surgeon-in-chief, and chair of the centre’s department of surgery, said highly variable utilisation rates for a diverse group of surgical procedures are commonly attributed to physician practice patterns rather than clinical considerations. “A previous investigation by our research team showed that variations in the rates of carotid endarterectomy actually reflected regional risk factors for atherosclerosis not physician density or other socioeconomic drivers,” said Gewertz. “In this study we examined the use of EVAR from 2001 to 2006 to test our hypothesis that the utilisation of innovative vascular procedures by vascular surgeons more closely reflects disease prevalence and consistent clinical judgment than non-medical considerations.”
Data for the study was taken for the Nationwide Inpatient Samples and State Inpatient Databases. The total number of aneurysms repaired has not changed significantly (from 45,828 in 2001 to 45,111 in 2006). During this same time period the number of open aortic aneurysm repairs nationwide decreased by 48%, while the number of aneurysms repaired endovascularly increased by 105%. “We examined multiple metrics pertaining to clinical risk factors, socioeconomic status, access to care, provider distribution and local healthcare capacity and quantified them for each state,” said Gewertz. He added that regional malpractice pressure, specifically the number of paid claims and mean malpractice premium, both exhibited positive correlations with the EVAR rate.
Researchers noted that in 2005 the utilisation rate of EVAR among 29 states throughout the United States ranged widely from 39.3% to 69.9%. Use of EVAR was highest in states with higher incidences of aneurysms and greater number of deaths from heart disease, as well as in states with the greater number discharges for diabetes, carotid stenosis and chronic obstructive pulmonary disorder; EVAR is well correlated with higher risk populations (the number of diabetic patients and deaths secondary to heart disease).
“Little has been known about what medical and non-medical factors influence the penetration of minimally invasive vascular surgical repair, specifically EVAR, into the healthcare market,” said Gewertz. “Despite the progressive utilisation of this progressive and innovative technique there is still considerable variation between states. Our key observation was that increased EVAR use correlated most closely with higher risk patient populations and increased experience in treating aneurysms, and that use was not strongly influenced by many of the socioeconomic measures thought to be predictive of the new technology. The appropriate matching of EVAR use with clinical indications may be explained by the fact that during the study vascular surgery specialists were responsible for carrying out virtually all treatments for aortic aneurysm disease.”