1. University of Colorado School of Medicine; Aurora CO USA
2. University of Glasgow; Glasgow UK
3. Veterans Affairs Medical Center and University of Minnesota; Minneapolis MN USA
4. University of California San Francisco; San Francisco CA USA
5. Medical University of South Carolina and the RHF Department of Veterans Affairs Medical Center; Charleston SC USA
6. Washington Veterans Affairs Medical Center and Georgetown University; Washington DC USA
7. Population Health Research Institute and McMaster University; Hamilton Ontario Canada
8. University Pierre et Marie Curie Paris VI, La Pitié-Salpétrière Hospital Paris; France