Fig. 2From: How do 66 European institutional review boards approve one protocol for an international prospective observational study on traumatic brain injury? Experiences from the CENTER-TBI studyDetailed overview of primary IRB review rounds and duration. This figure provides a detailed overview of the number of primary local and central IRB review rounds and their duration in days. *The number of review rounds was only reported for the initial center of each country. **Information on the first review round was missing. ***Only the total number of days was availableBack to article page