title: Relevance of current guidelines for organizing an anticoagulation clinic.
abstract: OBJECTIVE
  To describe variations in the structure of anticoagulation clinic (ACC) care within the Veterans Health Administration (VA) and to identify structures of care that are associated with better site-level anticoagulation control.
  
  
  METHODS
  Questionnaire correlated with automated clinical data.
  
  
  METHODS
  We characterized 90 VA ACCs using a questionnaire administered by the VA Central Office. Site descriptors included staffing levels, provider training, visit modalities, quality improvement programs, documentation, and care coordination. Patient outcomes were measured by site mean risk-adjusted percentage time in therapeutic range, a measure of anticoagulation control over time. Our study was powered to detect a 3% difference in risk-adjusted percentage time in therapeutic range, a small-to-moderate effect size, between sites with and without a certain characteristic.
  
  
  RESULTS
  We observed considerable variation in the structure of ACC care. For example, 48 sites had fewer than 400 patients per provider, 25 sites had 400 to 599 patients per provider, and 17 sites had 600 patients or more per provider. However, none of the site characteristics measured were significantly related to anticoagulation control.
  
  
  CONCLUSIONS
  We found substantial variation in guideline-targeted organizational and management features of ACC care within the VA. However, no single feature was associated with better anticoagulation control. Current guidelines for organizing an ACC may have limited relevance for improving patient outcomes.
authors: Center for Health Quality, Outcomes, and Economic Research, Bedford VA Medical Center, MA 01730, USA. adamrose@bu.edu
authors: Adam J
authors: AJ
authors: Rose
authors: Elaine M
authors: EM
authors: Hylek
authors: Al
authors: A
authors: Ozonoff
authors: Arlene S
authors: AS
authors: Ash
authors: Joel I
authors: JI
authors: Reisman
authors: Patricia P
authors: PP
authors: Callahan
authors: Margaret M
authors: MM
authors: Gordon
authors: Dan R
authors: DR
authors: Berlowitz