1. University of Washington, USA; The University of British Columbia, Canada
2. The University of British Columbia, Canada
3. The University of British Columbia, Canada; University of Saskatchewan, Canada
4. University of Miami, USA
5. Arizona State University, USA
6. The University of North Carolina at Chapel Hill, USA
7. University of North Carolina at Greensboro, USA
8. University of Notre Dame, USA
9. Michigan State University, USA
10. Yale School of Public Health, USA
11. Northwestern University, USA