1. Centre for Menstrual Cycle and Ovulation Research, Division of Endocrinology and Metabolism, Department of Medicine, University of British Columbia and Vancouver Coastal Health Research Institute, Vancouver, BC, Canada V5Z 1M9
2. Department of Statistics and Actuarial Science, Simon Fraser University, Burnaby, BC, Canada V5A 1S6
3. The Margaret Smith Menopause Unit, Menopause Service, King Edward Memorial Hospital for Women, Perth, WA 6008, Australia