BACKGROUND/RATIONALE:
The number of dual users of VA and Medicare services grew 20% between 1998 and 2000. Dual use may adversely affect continuity of care or lead to unnecessary duplication of outpatient services.

OBJECTIVE(S):
1) What proportion of veterans use both VA and FFS Medicare for primary care, what are the characteristics of veterans who use both systems, and what are the determinants of dual use? 2) Is continuity of care different for dual users and veterans who obtain only VA primary care? 3) Do veterans who are dual users receive the same outpatient services from VA and FFS Medicare providers?

METHODS:
This was a retrospective cohort study of veterans who obtained primary care from 108 CBOCs and 72 primary care clinics in parent VAMCs in 2000. The final study sample included 15,520 Medicare-enrolled veterans. Data sources included VA administrative datasets and Medicare claims data for 2001-2004. We developed an algorithm to classify VA and Medicare outpatient visits into primary care, specialty care, and mental health care using provider specialty and CPT procedure codes. For continuity of primary are, we constructed the Modified Modified Continuity of Care index (MMCI) for veterans with at least 3 primary care visits in a year. We compared the MMCI across three groups based on their primary care use - VA only, Medicare only, and dual use. For duplication of care, we examined 1) dilated eye exam within 365 days for 2,089 patients with diabetes, 2) serum hemoglobin A1c test within 90 days for 3,586 patients with diabetes, 3) urine microalbumin for 3,092 patients with diabetes, and 4) PSA tests for 12,640 males 50 years or older (n=12,640).

FINDINGS/RESULTS:
Overall, we found high use of Medicare outpatient services among VA primary care patients for both primary and specialty care, but not mental health care. Patients enrolled in CBOCs appear to offset decreased VA use with increased Medicare use. The Medicare only group had the highest continuity of primary care measured by MMCI, followed by the VA only and dual use groups. We found a small proportion of duplication of care for three preventive services (3.7% for eye exam among diabetic patients, 2.5% for PSA test among males 50 years or older, and 3% for urine microalbumin for diabetic patients). However, 71% of diabetic patients had hemoglobin A1c tests in both VA and Medicare within 90 days.

IMPACT:
Increasing use of Medicare outpatient care among VA primary care users could impact chronic disease management, continuity of care and quality measurement. Further understanding of this widespread, apparent fracturing of care for veterans is needed to develop strategies for improving communication between VA and non-VA providers.

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External Links for this Project

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PUBLICATIONS:

None at this time.

DRA: Health Systems Science
DRE: none
Keywords: VA/non-VA comparisons
MeSH Terms: none