In our recent article  we neglected to provide full acknowledgement. We thank the investigators of the Canadian Study of Health and Aging for permission to use the data from this study. The Seniors' Independence Research Program, through the National Health Research and Development Program (NHRDP) of Health Canada (project no. 6606-3954-MC(S)) funded the core study. Pfizer Canada Incorporated through the Medical Research Council/Pharmaceutical Manufacturers Association of Canada Health Activity Program, NHRDP (project no. 6603-1417-302(R)), Bayer Incorporated, and the British Columbia Health Research Foundation (project nos. 38 (93-2) and 34 (96-1)) provided additional funding. The study was coordinated through the University of Ottawa and the Division of Aging and Seniors, Health Canada. We gratefully acknowledge the discussions with Yujie Zhong, David Wolfson, and Masoud Asgharian.