Assessing variation in utilization for acute myocardial infarction in New York State.

BACKGROUND Wide variations exist in healthcare expenditures, though most prior studies have assessed aggregate utilization. We sought to examine healthcare utilization variation in New York State by assessing hospitals in peer groups of similar capabilities. METHODS Using charge data in New York State from the 2008 Statewide Planning and Research Cooperative System (SPARCS) and cost-to-charge ratios at the cost-center level drawn from Institutional Cost Reports, we calculated total, routine, and ancillary costs for patients discharged with an acute myocardial infarction (AMI) diagnosis in 2008. We assessed the correlation of these cost data to Hospital Referral Region (HRR) Medicare reimbursement data from the 2007 Dartmouth Atlas of Health Care. After describing hospital level cost variability, we examined characteristics associated with higher costs within peer groups of similar cardiac care capabilities. RESULTS We found greater costs in hospitals providing the highest level of cardiovascular services, with cardiac surgery capable hospitals and non-invasive hospitals having total costs of $21,166 and $9268 per AMI discharge, and ancillary costs of $12,006 and $4167 per AMI discharge, respectively. Substantial variability in utilization existed in all levels of hospitals and across individual departmental cost centers. The two factors most frequently associated with higher total and ancillary costs across peer groups were patient case mix index and major or minor teaching status. CONCLUSIONS Significant variation in cost per AMI discharge exists even within peer groups of hospitals with similar cardiac care capabilities. IMPLICATIONS These findings support measurement and analysis at the hospital level to further understand the reasons for variation in utilization.