The full-text version of this article contains a data supplement. (recommendation 1), drug-interaction management (recommen- dation 2), point-of-care international normalized ratio (INR) testing (recommendations 3 and 4), INR recall interval selection (recommen- dations 5 and 6), laboratory monitoring of the anticoagulant response (recommendations 7-9), transitions between anticoagulants (recom- mendation 10), the use of specialized anticoagulation-management services (AMSs) (recommendation 11), structured patient education (recommendation 12), efforts to improve adherence to anticoagulant- medication regimens (recommendations 13a-d), invasive procedure management (recommendations 14 and 15), excessive anticoagulation and bleeding management (recommendations 16, 17, 18a and b, 19, and 20), anticoagulant resumption following bleeding (recommendation 21), and renal function monitoring (good practice statements). These guidelines are based on updated and original systematic reviews of evidence developed under the direction of the McMaster University GRADE Centre. The panel followed best practice for guideline development recommended by the Institute of Medicine and the Guidelines International Network.2-5 The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach6-12 to assess certainty in evidence and formulate recommendations. Interpretation of strong and conditional recommendations The strength of a recommendation is expressed as either strong ( the guideline panel recommends ), or conditional ( the guideline panel suggests ) and has the following interpretations. Strong recommendation c For patients: Most individuals in this situation would want the recommended course of action, and only a small proportion would not. c For clinicians: Most individuals should follow the recommended course of action. Formal decision aids are not likely to be needed to help individual patients make decisions consistent with their values and preferences. c For policy makers: The recommendation can be adopted as policy in most situations. Adherence to this recommendation according to the guideline could be used as a quality criterion or performance indicator. 