Date of Award


Document Type

Campus Access Dissertation


Health Services and Policy Management

First Advisor

Sudha Xirasagar


Background: Coronary artery bypass graft (CABG) is a widely used revascularization procedure in coronary artery disease treatment. Previous studies have investigated costs among patients receiving CABG; however, none have addressed differences in mean costs of care related to payer source and time to CABG surgery. We posit that greater resource use is associated with the payer providing the most favorable reimbursement rates. This study will determine whether greater hospital resource use is associated with commercial fee-for-service plans compared to Medicare and Medicaid plans. We studied the association of in-hospital cost with plan type after stratifying by time to CABG (early, delayed and late per prevailing literature) among patients with non-ST segment elevated AMI (NSTEMI) using secondary claims data.

Objective: This research investigates in-hospital costs to treat patients with NSTEMI by analyzing a.) the association between cost and payer source and b.) the association between cost and time to CABG.

Methods: A retrospective analysis of claims data from 429 member hospitals of the largest healthcare organization consortium in the U.S., including all 31,138 adult AMI (NSTEMI) patients aged 18-89 years who received CABG from January 2006 through December 2010. Time to CABG was defined as early (< days, n=9,149), delayed (3-7 days, n=13,550), and late (>7 days, n=8,439). Generalized linear and multinomial logistic regression models were used. Independent variables include payer source, PTCA provision, hospital bed size, geographic region, APR-DRG (patient severity measure), age group, race, and gender.

Results/Conclusion: Hospital costs are significantly higher for Medicare and Medicaid plans compared to patients with Commercial Fee-For-Service (FFS) plans (p=0.0018 and <0.0001, respectively). Patients with Medicare and Medicaid plans are more likely to have late CABG than Commercial FFS plans (Odds ratio=1.354 and 1.359, respectively). Mean in-hospital costs are higher for patients receiving late CABG compared to early CABG ($65,234 vs. $40,934, p=<0.0001). More research is needed in order to explore the association between hospital and payer characteristics relating to the optimum time to coronary bypass.