1. Groupe de recherche PRIMUS Department of Family Medicine University of Sherbrooke 3001 12e Ave N Sherbrooke Quebec Canada J1H 5N4
2. Department of Computer Science University of Sherbrooke 2500 boulevard de l'Université Sherbrooke Quebec Canada J1K 2R1
3. Translational Gerontology Branch Longitudinal Studies Section National Institute on Aging National Institutes of Health MedStar Harbor Hospital 3001 S. Hanover Street Baltimore Maryland 21225 USA
4. Mailman School of Public Health Columbia University 722 W. 168th Street R1408 New York NY 10032 USA