1. Department of Epidemiology, Biostatistics and Occupational Health McGill University Montreal Quebec Canada
2. Centre for Clinical Epidemiology Lady Davis Institute Jewish General Hospital Montreal Quebec Canada
3. Departments of Medicine and of Epidemiology, Biostatistics and Occupational Health McGill University Montreal Quebec Canada
4. Departments of Pediatrics and of Epidemiology, Biostatistics and Occupational Health McGill University Montreal Quebec Canada
5. Division of Endocrinology Jewish General Hospital Montreal Quebec Canada