CABG utilization and Medicare referral patterns in VISN 1

Session number: 1138

Abstract title: CABG utilization and Medicare referral patterns in VISN 1

Author(s):
William Weeks, MD, MBA - Veterans Rural Health Initiative Senior Scholar, VA Quality Scholars Program VISN 1 Patient Safety Center of Inquiry White River Junction VAMC
Rebecca P Lamkin, MA - Massachusetts Veterans Epidemiological Research and Information Center (MAVERIC)
Steven M Wright, PhD - Office of Quality and Performance (VAHQ) &, Massachusetts Veterans Epidemiological Research and Information Center (MAVERIC) CHEQER, Boston, MA

Objectives: The additional travel distance required for veterans to obtain regionalized Coronary Artery Bypass Grafting (CABG) surgery through VHA may implicitly restrict access to that care. When veterans have access to multiple systems of care, such as when they are enrolled in Medicare, their utilization patterns may be influenced by the availability of local care. We wanted to examine the relationship CABG utilization rates and Dartmouth Atlas defined Hospital Referral Regions (HRRs) that reflect Medicare enrollees’ CABG utilization patterns.

Methods: We used the merged VHA/Medicare database to examine VHA and Medicare-funded CABG utilization for enrolled veterans who received care exclusively in VISN 1 from 1997 through 1999. We identified two age groups (45-64, and 65+) and used zip code of residence to determine whether each veteran lived in an HRR that contained a regional VHA CABG program in West Roxbury, MA or West Haven, CT (VHA HRR) or not. Using ICD-9 codes, we identified VHA and Medicare-funded CABGs. We used t-test analysis to compare utilization rates for veterans who lived in a VHA HRR to those who did not.

Results: Approximately 15% of enrolled veterans in both age cohorts lived in a VHA HRR. Veterans who lived in a VHA HRR had a higher rate of VHA CABG utilization than those who did not (45-64 year old group: 15.7 CABGs per 1000 enrolled veterans for VHA HRR residents vs. 13.7, p<.0001; 65+ group, 14.4 vs.13.7, p<.0001). In the younger age group, veterans who lived in a VHA HRR had lower rate of Medicare CABG utilization (8.1 vs. 9.5, p<.0001); in the older age group the opposite was found (22.0 vs. 20.2, p<.0001).

Conclusions: Veterans who did not live in a VHA HRRs had lower VHA CABG utilization rates. In the younger age group, Medicare substitution of CABG in veterans who did not live in a VHA HRR was apparent. When they became age-eligible for Medicare, veterans were much more likely to use Medicare, regardless of residence.

Impact statement: Regionalized services may implicitly restrict access to care for veterans. VHA should consider local patterns of care and different care delivery models to facilitate service access.