Relevance of current guidelines for organizing an anticoagulation clinic

UMMS Affiliation

Department of Quantitative Health Sciences

Publication Date


Document Type



Administration, Oral; Ambulatory Care Facilities; Anticoagulants; Hospitals, Veterans; Humans; International Normalized Ratio; Pharmacy Service, Hospital; *Practice Guidelines as Topic; *Quality Improvement; Questionnaires; United States; United States Department of Veterans Affairs; Warfarin


Biostatistics | Epidemiology | Health Services Research


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.

STUDY DESIGN: 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.


Am J Manag Care. 2011 Apr;17(4):284-9.

Journal/Book/Conference Title

The American journal of managed care

PubMed ID


Related Resources

Link to Article in PubMed