1. From the Division of General Internal Medicine, Department of Medicine (K.T., J.P., S.P., N.K., W.-S.C.), University of British Columbia, Vancouver, Canada
2. Department of Obstetrics and Gynecology (J.R.), University of British Columbia, Vancouver, Canada
3. Center for Health Evaluation and Outcome Sciences, Vancouver, British Columbia, Canada (N.K.)
4. Division of General Internal Medicine, Department of Medicine, University of Alberta, Edmonton, Canada (R.P.).