Net clinical benefit of anticoagulation for atrial fibrillation following intracerebral hemorrhage

Following an anticoagulation-associated intracerebral hemorrhage (ICH), whether and when to resume anticoagulation is controversial. Patient-level recurrence risk is difficult to predict with accuracy, but time-based recurrence risk may be more predictable. To better inform clinical decisions, we set out to estimate the net clinical benefit of anticoagulation over time among patients with atrial fibrillation. Using a large administrative dataset with 5339 index ICH hospitalizations and 132 readmissions for ICH, we created a two-stage prediction model, first predicting patient-level risk of recurrence and then predicting timing, conditional on recurrence. A log-normal survival function best explained the declining risk of recurrent ICH over time. We then compared risk of recurrent ICH over time against ischemic stroke risk, weighting the two outcomes to compute the net clinical benefit on each day following an index discharge. Using a bootstrapping approach, we identified the first day following discharge on which anticoagulation would lead to net benefit rather than net harm. Anticoagulation remains harmful for at least 11 days following index discharge and, depending on desired confidence level and assumptions, may remain harmful for as long as 62 days after discharge. Results were sensitive to the overall ICH recurrence risk. Although patient-level risk of recurrent ICH is difficult to predict accurately, recurrence risk declines rapidly over time. The survival function presented herein can inform decision-analytic models regarding when patients should resume anticoagulation following ICH.