Alexandra Barratt (MBBS, MPH, PhD) is an epidemiologist and Professor of Public Health in the School of Public Health, University of Sydney. She has led a wide range of health services research over the last 20 years, including many projects on early detection programs for breast and prostate cancer. She leads a team of researchers who have been awarded NHMRC funding for a Centre of Research Excellence which forms part of Wiser Healthcare (http://wiserhealthcare.org.au/) a research collaboration for reducing overdiagnosis and overtreatment. She is currently co-chair of the Scientific Committee for Preventing Overdiagnosis (http://www.preventingoverdiagnosis.net/), an international collaboration to wind back the harms of Too Much Medicine. In 2006 and 2007 she won back-to-back Australian Museum Eureka prizes and is an Australian Museum Eureka Prize Ambassador.