title: Exploring the association of dual use of the VHA and Medicare with mortality: separating the contributions of inpatient and outpatient services.
abstract: BACKGROUND
  Older veterans may use both the Veterans Health Administration (VHA) and Medicare, but the association of dual use with health outcomes is unclear. We examined the association of indirect measures of dual use with mortality.
  
  
  METHODS
  Our secondary analysis used survey, claims, and National Death Index data from the Survey on Assets and Health Dynamics among the Oldest Old. The analytic sample included 1,521 men who were Medicare beneficiaries. Veterans were classified as dual users when their self-reported number of hospital episodes or physician visits exceeded that in their Medicare claims. Veterans reporting inpatient or outpatient visits but having no Medicare claims were classified as VHA-only users. Proportional hazards regression was used.
  
  
  RESULTS
  897 (59%) of the men were veterans, of whom 134 (15%) were dual users. Among dual users, 60 (45%) met the criterion based on inpatient services, 54 (40%) based on outpatient services, and 20 (15%) based on both. 766 men (50%) died. Adjusting for covariates, the independent effect of any dual use was a 38% increased mortality risk (AHR = 1.38; p = .02). Dual use based on outpatient services marginally increased mortality risk by 45% (AHR = 1.45; p = .06), and dual use based on both inpatient and outpatient services increased the risk by 98% (AHR = 1.98; p = .02).
  
  
  CONCLUSIONS
  Indirect measures of dual use were associated with increased mortality risk. New strategies to better coordinate care, such as shared medical records, should be considered.
authors.affiliation: Center for Research in the Implementation of Innovative Strategies in Practice, Iowa City VA Medical Center, Iowa City, IA 52246, USA. fredric-wolinsky@uiowa.edu
authors.forename: Fredric D
authors.initials: FD
authors.lastname: Wolinsky
authors.forename: Hyonggin
authors.initials: H
authors.lastname: An
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Miller
authors.forename: Gary E
authors.initials: GE
authors.lastname: Rosenthal
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000553:Ambulatory Care / Q000191:economics / Q000706:statistics & numerical data*; D016000:Cluster Analysis; D003266:Continuity of Patient Care; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D017050:Episode of Care; D017052:Hospital Mortality / Q000639:trends*; D006787:Hospitals, Veterans / Q000191:economics / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D006278:Medicare / Q000706:statistics & numerical data*; D016016:Proportional Hazards Models; D014481:United States; D014728:Veterans / Q000706:statistics & numerical data*