1. School of Public Health and Social Policy, University of Victoria, Victoria, BC V8W 2Y2, Canada
2. Gerontology Program, San Francisco State University, San Francisco, CA 92262, USA
3. Dalla Lana School of Public Health, University of Toronto, Toronto, ON M5S 2V8, Canada
4. Gerontology Research Centre, Simon Fraser University, Vancouver, BC V6B 5K3, Canada