title: Dual use of Medicare and the Veterans Health Administration: are there adverse health outcomes?
abstract: BACKGROUND
  Millions of veterans are eligible to use the Veterans Health Administration (VHA) and Medicare because of their military service and age. This article examines whether an indirect measure of dual use based on inpatient services is associated with increased mortality risk.
  
  
  METHODS
  Data on 1,566 self-responding men (weighted N = 1,522) from the Survey of Assets and Health Dynamics among the Oldest Old (AHEAD) were linked to Medicare claims and the National Death Index. Dual use was indirectly indicated when the self-reported number of hospital episodes in the 12 months prior to baseline was greater than that observed in the Medicare claims. The independent association of dual use with mortality was estimated using proportional hazards regression.
  
  
  RESULTS
  96 (11%) of the veterans were classified as dual users. 766 men (50.3%) had died by December 31, 2002, including 64.9% of the dual users and 49.3% of all others, for an attributable mortality risk of 15.6% (p < .003). Adjusting for demographics, socioeconomics, comorbidity, hospitalization status, and selection bias at baseline, as well as subsequent hospitalization for ambulatory care sensitive conditions, the independent effect of dual use was a 56.1% increased relative risk of mortality (AHR = 1.561; p = .009).
  
  
  CONCLUSIONS
  An indirect measure of veterans' dual use of the VHA and Medicare systems, based on inpatient services, was associated with an increased risk of death. Further examination of dual use, especially in the outpatient setting, is needed, because dual inpatient and dual outpatient use may be different phenomena.
authors.affiliation: Center for Research in the Implementation of Innovative Strategies in Practice, Iowa City Health Care System, 601 Highway 6 West, Iowa City, IA52246, USA. fredric-wolinsky@uiowa.edu
authors.forename: Fredric D
authors.initials: FD
authors.lastname: Wolinsky
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Miller
authors.forename: Hyonggin
authors.initials: H
authors.lastname: An
authors.forename: Paul R
authors.initials: PR
authors.lastname: Brezinski
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Vaughn
authors.forename: Gary E
authors.initials: GE
authors.lastname: Rosenthal
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003669:Deductibles and Coinsurance / Q000706:statistics & numerical data*; D017050:Episode of Care; D006302:Health Services Research; D006787:Hospitals, Veterans / Q000592:standards / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D006278:Medicare / Q000592:standards / Q000706:statistics & numerical data*; D009026:Mortality; D017063:Outcome Assessment, Health Care; D016016:Proportional Hazards Models; D019984:Quality Indicators, Health Care; D018570:Risk Assessment; D015983:Selection Bias; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D014493:United States Department of Veterans Affairs; D014728:Veterans / Q000706:statistics & numerical data*