Correction: Treating Recurrent Headache: Naproxen or Sumatriptan?

A correction to a summary published on August 20, 2010

In the summary Treating Recurrent Headache: Naproxen or Sumatriptan?, published online August 20, 2010, the number and proportion of patients who reported headache recurrence within 48 hours after emergency department discharge should have been listed as 280 (70%), not as 288 (51%). We have corrected the error in our original summary, and we apologize for the error.