Updated 2016 and 2017 by Dr Michelle Scollo, Megan Bayly, and Dr Becky Freeman; further updated 2018 by Dr Elizabeth Greenhalgh, Kate Hagan, Amanda Vittiglia, and Dr Kathy Barnsley
Fourth edition (2012) updated by Dr Becky Freeman
Third edition (2008) drafted by Margaret Winstanley
See also our 'InDepth' discussions of: