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:

Journal Articles

1. Liu CF, Burgess JF, Manning WG, Maciejewski ML. Beta-binomial regression and bimodal utilization. Health services research. 2013 Oct 1; 48(5):1769-78. [view]
2. Burgess JF, Maciejewski ML, Bryson CL, Chapko M, Fortney JC, Perkins M, Sharp ND, Liu CF. Importance of health system context for evaluating utilization patterns across systems. Health economics. 2011 Feb 1; 20(2):239-51. [view]
3. Maciejewski ML, Birken S, Perkins M, Burgess JF, Sharp N, Liu CF. Medicare managed care enrollment by disability-eligible and age-eligible veterans. Medical care. 2009 Nov 1; 47(11):1180-5. [view]
4. Liu CF, Manning WG, Burgess JF, Hebert PL, Bryson CL, Fortney J, Perkins M, Sharp ND, Maciejewski ML. Reliance on Veterans Affairs outpatient care by Medicare-eligible veterans. Medical care. 2011 Oct 1; 49(10):911-7. [view]
5. Liu CF, Bryson CL, Burgess JF, Sharp N, Perkins M, Maciejewski ML. Use of outpatient care in VA and Medicare among disability-eligible and age-eligible veteran patients. BMC health services research. 2012 Mar 5; 12(1):51. [view]
6. Liu CF, Chapko M, Bryson CL, Burgess JF, Fortney JC, Perkins M, Sharp ND, Maciejewski ML. Use of outpatient care in Veterans Health Administration and Medicare among veterans receiving primary care in community-based and hospital outpatient clinics. Health services research. 2010 Oct 1; 45(5 Pt 1):1268-86. [view]

VA Cyberseminars

1. Liu C. Use of Primary Care in VA and Medicare among VAMC and CBOC Patients - HERC Cyber Seminar. [Cyberseminar]. 2008 Sep 17. [view]

Conference Presentations

1. Liu C, Burgess JF, Manning WG, Maciejewski ML. Beta-Binomial Regression for Bimodal Utilization. Poster session presented at: VA HSR&D / QUERI National Meeting; 2012 Jul 19; National Harbor, MD. [view]
2. Tarlov E, Maciejewski ML, Liu C, Hynes DM. Current Applications and Future Directions in VA-CMS Data. Presented at: VA HSR&D National Meeting; 2011 Feb 17; Baltimore, MD. [view]
3. Maciejewski ML, Burgess J, Bryson CL, Perkins M, Fortney JC, Manning WG, Chapko M, Sharp N, Liu CF. Factors Associated with Veterans' Dual Use of VA and Medicare Primary Care Services. Poster session presented at: VA HSR&D National Meeting; 2008 Feb 14; Baltimore, MD. [view]
4. Maciejewski ML, Burgess J, Bryson CL, Perkins M, Fortney JC, Manning WG, Chapko M, Sharp N, Liu CF. Factors Associated with Veterans' Dual Use of VA and Medicare Primary Care Services. Poster session presented at: AcademyHealth Annual Research Meeting; 2008 Jun 9; Washington, DC. [view]
5. Burgess JF, Maciejewski ML, Perkins M, Sharp ND, Liu C. Integrating Clinical Data Warehouses: How Can Multi-System Care for Older Veterans be Measured Consistently? Presented at: AcademyHealth Annual Research Meeting; 2008 Jun 14; Washington, DC. [view]
6. Liu C, Manning W, Burges JF, Hebert PL, Bryson CL, Fortney J, Perkins M, Sharp N, Maciejewski ML. Reliance on VA Outpatient Care among Medicare-eligible Veterans. Presented at: AcademyHealth Annual Research Meeting; 2011 Jun 13; Seattle, WA. [view]
7. Liu C, Manning F, Burges JF, Hebert PL, Bryson CL, Fortney J, Perkins M, Sharp N, Maciejewski ML. Reliance on VA Outpatient Care among Medicare-eligible Veterans. Presented at: Society of General Internal Medicine Annual Meeting; 2011 May 5; Phoenix, AZ. [view]
8. Liu C, Manning F, Burges JF, Hebert PL, Bryson CL, Fortney J, Perkins M, Sharp N, Maciejewski ML. Reliance on VA Outpatient Care among Medicare-eligible Veterans. Presented at: International Health Economics Association Biennial World Congress on Health Economics; 2011 Jul 12; Toronto, Canada. [view]
9. Burgess JF, Maciejewski ML, Bryson CL, Sharp ND, Perkins M, Chuan-Fen L. Use of Outpatient Care in VA & Medicare among VAMC & CBOC Patients. Paper presented at: AcademyHealth Annual Research Meeting; 2009 Jun 28; Chicago, IL. [view]
10. Liu C, Chapko MK, Burgess J, Bryson CL, Perkins M, Fortney J, Manning W, Sharp ND. Use of Outpatient Care in VA and Medicare among CBOC and VAMC Patients. Presented at: International Health Economics Association Biennial World Congress on Health Economics; 2009 Jul 14; Beijing, China. [view]
11. Maciejewski ML, Liu CF, Bryson CL, Sharp N, Perkins M. Use of Outpatient Care in VA and Medicare among Disability-Eligible and Age-Eligible Veterans. Poster session presented at: AcademyHealth Annual Research Meeting; 2010 Jun 28; Boston, MA. [view]
12. Maciejewski ML, Liu CF, Bryson CL, Sharp N, Burgess J. Use of Outpatient Care in VA and Medicare among Disability-Eligible and Age-Eligible Veterans. Paper presented at: Society of General Internal Medicine Annual Meeting; 2010 Apr 30; Minneapolis, MN. [view]
13. Liu CF, Chapko MK, Burgess J, Bryson CL, Perkins M, Fortney J, Manning W, Sharp N. Use of Outpatient Care in VA and Medicare among VAMC and CBOC Patients. Poster session presented at: VA HSR&D National Meeting; 2009 Feb 13; Washington, DC. [view]
14. Liu CF, Chapko M, Burgess J, Bryson C, Perkins M, Forney J, Manning W, Sharp N, Maciejewski ML. Use of Primary Care in VA and Medicare among VAMC and CBOC Patients. Poster session presented at: AcademyHealth Annual Research Meeting; 2008 Jun 12; Washington, DC. [view]
15. Liu CF. Use of Primary Care in VA and Medicare among VAMC and CBOC Patients. Presented at: American Society of Health Economists Biennial Conference; 2008 Jun 23; Durham, NC. [view]
16. Maciejewski ML, Perkins M, Hendricks A, Wright S, Hynes D. Working with VA and Medicare Data: Matching by Care Type. Presented at: VA HSR&D National Meeting; 2007 Feb 14; Washington, DC. [view]

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