In their meta-analysis of prophylactic anti-coagulants, Lloyd et al also reported the incidence of major bleeding, an unwanted harm caused by the treatment. They reported an incidence of 1% in the prohylaxis arm and 0.5% in the control arm.
Calculate the NNT for major bleeding.
THE ANSWER...
An additional 0.5% of people experienced major bleeds with prophylactic treatment.
Click the "exercise 2" link below for the next exercise on NNH.