Is the cost of care for Coronary Artery Bypass Graft (CABG) patients among Acute Myocardial Infarction patients associated with payer and plan type and time to CABG?

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 health plan type and time to CABG surgery. We posit that greater resource use is associated with plan types 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.

Research Objectives:

To investigate mean in-hospital costs to treat patients with NSTEMI by analyzing: A) The association between cost and health plan type 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 31,413 adult AMI (NSTEMI) patients aged 18-89 years who received CABG from January 2006 through December 2010. Time to CABG was defined as early (<48 hours, n=6,741), delayed (3-7 days, n=13,552), and late (>7 days, n=2,946). Generalized linear and multinomial logistic regression models were used. Independent variables include plan type, 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 fee-for-service and Medicaid plans compared to patients with commercial fee-for-service plans (p=0.0001 and 0.0222, respectively). Patients with Medicare and Medicaid plans are more likely to have late CABG than commercial fee-for-service plans (OR=1.487 and 1.507). Mean in-hospital costs are higher for patients receiving late CABG compared to early CABG ($100338 vs. $84379, p=<0.0001). Additional analyses are underway to verify the findings.