1. Statistics Collaborative, Washington DC, USA,
2. University of California, San Diego, California, USA
3. Harvard Medical School, Boston, Massachusetts, USA
4. National Center for Complementary and Alternative Medicine, Bethesda, Maryland, USA
5. Duke University Medical School, Durham, North Carolina, USA
6. University of Wisconsin, Madison, Wisconsin, USA
7. Virginia Commonwealth University, Richmond, Virginia, USA
8. National Institutes of Health, Bethesda, Maryland, USA
9. Creighton University, Omaha, Nebraska, USA
10. University of Pittsburgh, Pittsburgh, Pennsylvania, USA
11. Georgetown University, Washington DC, USA
12. McMaster University, Hamilton, Ontario, Canada