Guidelines on anticoagulant treatment in atrial fibrillation in Great Britain: variation in content and implications for treatment.

OBJECTIVE: To describe the content of guidelines on the use of anticoagulant treatment in patients with atrial fibrillation and the impact of variations in guidelines on treatment.
DESIGN: Postal survey of guidelines, semistructured interview with lead developers of guidelines, and application of guidelines to patient sample.
SUBJECTS: 15 lead developers of the 20 guidelines identified in the postal survey were interviewed. 100 patients over 65 with atrial fibrillation to whom the guidelines were applied. MAIN OUTCOME MEASURES: Evaluation of guidelines and the methods of dissemination, implementation, review, and evaluation; proportion of patients recommended for anticoagulant treatment by each guideline; and level of agreement between guidelines.
RESULTS: There was considerable variation in whether anticoagulant treatment was recommended for subjects (range 13% to 100%, kappa = 0.12). Guidelines varied greatly in advice on treatment by age, the use of echocardiography, and the target value or range of the international normalised ratio (8 of the 20 guidelines included values unlikely to be effective). Development was unsystematic; evidence based approaches were rarely used, 9 of the 15 lead developers had developed the guidelines themselves, and the 6 guidelines developed by groups relied on informal consensus. Methods to support effective dissemination, implementation, and evaluation were limited.
CONCLUSION: The widespread non-systematic production of guidelines has led to considerable variation with implications for the quality of care and clinical decision making. There is a need for a central, well funded programme of guideline development to ensure that valid guidelines are produced and disseminated.