Alongside the many thousands of Cochrane reviews of the effects of health care interventions, is a review of decision aids that might help people make decisions about treatment or screening. This was first published in January 2003 and the fifth update has been published 21 years later. Here's the current lead author, Dawn Stacey from the University of Ottawa and Ottawa Hospital Research Institute in Canada, who's been working on the review for all that time to tell us about the need for the review and its latest findings.