AF tool overestimates stroke risk

A widely used decision tool for atrial fibrillation is overestimating stroke risk that may result in some patients being started on warfarin unnecessarily, a UK study suggests.

NPS MedicineWise guidelines currently advise that patients with a CHA2DS2-VASc score  of 1 will benefit from anticoagulation for stroke prevention.

But UK researchers say the decision tool is inaccurate because it is based on data from hospital patients rather than primary care patients.

When they applied the decision tool to almost 30,000 primary care patients with AF,