Is Veteran User Status an Independent Risk Factor for Mortality After Private Sector CABG?

1. Is Veteran User Status an Independent Risk Factor for Mortality After Private Sector CABG? William B. Weeks, MD, MBA Dorothy A. Bazos, Ph.D. David M. Bott, Ph.D. Stacey L. Campbell, MPH Edward L. Hannan, Ph.D. Michael J. Racz, MA Stephen M. Wright, Ph.D. Elliott S. Fisher, MD, MPH This work was funded by the HSR&D Grant ACC 01-117-1 (Utilization, System of Care, and Outcome of CABG in New York Veterans)

2. Background • Improving the quality of care for VHA patients with Coronary Artery Disease is a priority. • Prior research has reported worse risk-adjusted outcomes for veterans following AMI and CABG. • Concerns remain that previous studies may not have adequately accounted for the increased burden of illness of veterans who rely on the VHA health care system for their care.

3. We know that many veterans who receive care in the VHA (VHA users) obtain bypass surgery in the private sector... Study Question One • Are VHA users who obtain CABG in the private sector sicker than non-VHA users? • Study Question Two • Is being a VHA user an independent risk factor for mortality following CABG in the private sector?

4. Data Sources(Study period:1997-1999) • VHA • Administrative and Enrollment files • New York State Department of Health • Cardiac Surgery Reporting System (CSRS)

5. Methods • Cohort study • Study population • Males only • Isolated CABG (no other heart or vascular surgery) • Private sector hospitals located in New York State • Discharged January 1, 1997 – December 31, 1999 • Comparison groups • VHA users • non-VHA users • Outcome • In-hospital mortality after CABG

6. Methods • Statistical Methods • Logistic regression models • To determine expected mortality risk for each participant • To determine whether VHA user status is an independent risk factor for mortality • Risk Factors – defined by CSRS • Demographics • Comorbidity (e.g. diabetes, vascular disease) • Disease Severity • Models included hospital effects • This allows us to account for possibility that VHA patients received care in higher or lower quality hospitals

7. Male Population Having Isolated CABG in NY private sector cardiac facilities 1997-1999 Male VHA and non-VHA users n = 40,728 VHA user n = 3,009 non-VHA user n = 37,719 Deaths = 67 Deaths = 670 Results – Study Population

8. Are VHA users sicker?

9. Are VHA users sicker?

10. VHA users are sicker than others...

11. Veteran user status is not an independent risk factor for CABG mortality

12. Limitations • Only looked at CABG Surgery. • Only looked at male VHA users who had private sector CABG – male veterans having CABG in the VHA could still be sicker.

13. Conclusions • Male veterans having CABG in private sector facilities in NY, who are users of the VHA system tend to be sicker than male non-VHA users. • VHA user status is NOT an independent risk factor for CABG mortality in the private sector. • VHA users do as well as other male patients in regard to in-hospital mortality associated with CABG. • .

14. Implications • Opportunities exist for VHA to improve CABG outcomes by coordinating where CABG occurs in the private sector (hospitals with lower mortality rates). • Adequate risk adjustment should allow fair comparisons of VHA to non-VHA care for veterans.