Figure 3. Interventional trials in the ClinicalTrials.gov registry. A. Trials using the words “pragmatic” and/or “naturalistic” and which claim to be interventional (n=111). B. Number of trials among the 111 presented in panel A that are tagged as “Open” (still recruiting, ongoing or not closed yet, n=47). C. Trials in the ClinicalTrials.gov registry that claim to be interventional and are tagged as “Open” (n=28 882). The search was performed on May 5th 2011 using the terms “pragmatic* OR naturalistic*.” Colors indicate the intensity of studies in majorworld regions. Counts give the exact number of studies per region.