1. Department of Epidemiology and Community Medicine; University of Ottawa; Ottawa Canada
2. Department of Medicine; University of Ottawa; Ottawa Canada
3. Community Information and Epidemiological Technologies; Institute of Population Health; Ottawa Canada
4. MRC Biostatistics Unit; Cambridge UK
5. Centre for Reviews and Dissemination; University of York; York UK
6. School of Social and Community Medicine; University of Bristol; UK
7. Centre for Global Health; Institute of Population Health; Ottawa Canada
8. Clinical Trials and Evaluation Unit, School of Clinical Sciences; University of Bristol; UK