title: Use of administrative data to increase the practicality of clinical trials: Insights from the Women's Health Initiative.
abstract: To reduce research costs in the context of pragmatic trials, consideration is given to using administrative data (Medicare claims) to ascertain clinical outcomes.
  
  
  
  In the historical context of the Women's Health Initiative, the correspondence between selected cardiovascular events derived from Medicare claims was compared to those documented and adjudicated in this large-scale prevention trial.
  
  
  
  Classification performance varies somewhat by type of outcome, but hazard ratios and confidence intervals derived from the two data sources were quite comparable.
  
  
  
  These encouraging results provided the needed support to launch a new embedded pragmatic trial of physical activity that will rely heavily on Medicare claims to ascertain cardiovascular disease incidence in the majority of those randomized.
authors.affiliation: WHI Clinical Coordinating Center, Fred Hutchinson Cancer Research Center, Seattle, WA, USA garnet@whi.org.
authors.forename: Garnet L
authors.initials: GL
authors.lastname: Anderson
authors.affiliation: WHI Clinical Coordinating Center, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
authors.forename: Carolyn J
authors.initials: CJ
authors.lastname: Burns
authors.affiliation: WHI Clinical Coordinating Center, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Larsen
authors.affiliation: Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Shaw
mesh_terms: D000368:Aged; D002318:Cardiovascular Diseases / Q000453:epidemiology; D002986:Clinical Trials as Topic / Q000379:methods* / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D007345:Insurance Claim Review / Q000706:statistics & numerical data*; D006278:Medicare / Q000706:statistics & numerical data*; D008875:Middle Aged; D014481:United States / Q000453:epidemiology; D016387:Women's Health / Q000706:statistics & numerical data*
keywords: Medicare linkage; Pragmatic trials; claims data; misclassification; mismeasured outcomes