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14. Variation across VISNs in VA Enrollees’ Reliance on VA Care

Y Shen, Center for Health Quality, Outcomes, and Economic Research (CHQOER), an HSR&D Center of Excellence, Bedford, MA; Boston University School of Public Health; A Hendricks, Center for Health Quality, Outcomes, and Economic Research (CHQOER), an HSR&D Center of Excellence, Bedford, MA; Boston University School of Public Health; LM Kazis, Center for Health Quality, Outcomes, and Economic Research (CHQOER), an HSR&D Center of Excellence, Bedford, MA; Boston University School of Public Health; Office of Quality and Performance (10Q), Veterans Health Administration (VHA), Washington, DC

Objectives: To assess VA enrollees’ reliance on VA care across VISNs and explore the factors associated with the degree to which enrollees rely on VA care.

Methods: We used data from the insurance module (n=152,258) of the ‘1999 Large Health Survey of Veteran Enrollees’ (overall response rate of 63%). The large sample size in each VISN (from 2,633 in VISN 14 to 13,796 in VISN 8) gives sufficient statistical power to examine variation in reliance on VA care across VISNs. We measured the reliance rate of VA care by the proportion of respondents in each VISN who reported using VA only in the prior 12 months. To control for patients’ characteristics that may affect their choice to use VA, we estimated an expected reliance rate by a logistic regression model, including independent variables such as enrollees’ VA priority status, health status measured by veterans SF-36 physical (PCS) and mental (MCS) summary scores, alternative health care coverage such as Medicare and private insurance, and sociodemographic variables. We compared the observed and expected reliance rates for each VISN based on Z-scores.

Results: Overall, 39.8% of respondents reported using VA exclusively in the 12 months preceding the survey. The rate varied by a factor of 1.5 across VISNs: from 46.5% in VISN 15 to 30.2% in VISN 3. Logistic analysis showed that the following VA enrollees were more likely to use VA only: male, non-white, living alone, unmarried, having economic hardship, older age, less education, worse physical and mental health status, catastrophically disabled (VA priority status 4), low income (priority 5) and 50%+ service connected-disabled (priority 1) VA enrollees. Enrollees without public or private insurance coverage or with only very limited Medicare coverage were also more likely to seek all their care from VA. For example, the adjusted odds ratio of using VA only for those with VA priority 7 compared to those with priority 1 was 0.64. For individuals with Medicare supplementary coverage relative to those without any alternative coverage, the odds ratio of using VA only was 0.10. The observed reliance rates were significantly different from the expected in 13 VISNs (p<=0.05). The differences ranged from 3.7% (VISN 15) to –5.3% (VISN 10, -4.5% in VISN 3). About half of the variation of reliance on VA care across VISNs cannot be explained by patients’ characteristics.

Conclusions: This study found substantial variation in the VA enrollees’ reliance on VA care across VISNs, even after controlling for individual characteristics that are significantly associated with their reliance on VA care. Further studies are needed to identify other factors that may contribute to the geographic variation such as quality of care, availability of non-VA care.

Impact: These findings imply that VISNs with fewer patients relying completely on VA care need to coordinate care of their enrollees with other payers and these VISNs face more competition for their patients.