What is evidence? How can we evaluate it? What makes some scientific evidence more reliable than other scientific evidence? This video looks at the framework of the peer review system in science, identifies what is known as the “hierarchy of evidence”, and examines a checklist we can apply to different scientific claims to help us assess their reliability. Facebook page: https://www.facebook.com/ScienceLiteracyChannel/ Twitter page: https://twitter.com/SciLiteracyChan SOURCES: 1:20 : “List of academic databases and search engines”. Wikipedia. https://en.wikipedia.org/wiki/List_of_academic_databases_and_search_engines 3:41 : Garg et al. “Systematic Review and Meta-analysis: When One Study Is Just not Enough”. Clinical Journal of the American Society of Nephrology. Jan 2008. http://cjasn.asnjournals.org/content/3/1/253.full 3:55 : “Cochrane Database of Systematic Reviews”. Cochrane Library. http://www.cochranelibrary.com/cochrane-database-of-systematic-reviews/ 4:02 : “Appraising systematic reviews”. BMJ Clinical Evidence. http://clinicalevidence.bmj.com/x/set/static/ebm/toolbox/665052.html 4:09 : Eysenck, HJ. “Education And Debate Systematic Reviews: Meta-analysis and its problems”. BMJ. 24 Sep 1994. http://www.bmj.com/content/309/6957/789 4:16 : Siri-Tarino et al. “Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease.” American Journal of Clinical Nutrition. Mar 2010. http://www.ncbi.nlm.nih.gov/pubmed/20071648 4:37 : Stamler, J. “Diet-heart: a problematic revisit”. American Journal of Clinical Nutrition. 3 Feb 2010. http://ajcn.nutrition.org/content/91/3/497.full 4:41 : Scarborough, P & Rayner, M. “Meta-analysis of effect of saturated fat intake on cardiovascular disease: overadjustment obscures true associations”. American Journal of Clinical Nutrition. 9 Jun 2010. http://ajcn.nutrition.org/content/92/2/458.long 4:43 : Flegal et al. “Association of All-Cause Mortality With Overweight and Obesity Using Standard Body Mass Index Categories: A Systematic Review and Meta-analysis”. JAMA. 2 Jan 2013. http://jama.jamanetwork.com/article.aspx?articleid=1555137 5:02 : Willett, W. “Ask the Expert: Does being overweight really decrease mortality? No!” Harvard School of Public Health. 9 Jan 2013. https://www.hsph.harvard.edu/nutritionsource/2013/01/09/ask-the-expert-does-being-overweight-really-decrease-mortality-no/ 5:12 : LeLorier et al. “Discrepancies between Meta-Analyses and Subsequent Large Randomized, Controlled Trials”. New England Journal of Medicine. 21 Aug 1997 http://www.nejm.org/doi/full/10.1056/NEJM199708213370806 9:05 : Doll, R. & Hill, AB. “Lung Cancer and Other Causes of Death in Relation to Smoking”. BMJ. 10 Nov 1956. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2035864/ 9:10 : Doll et al. “Mortality in relation to smoking: 50 years' observations on male British doctors”. BMJ. 26 Jun 2004. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC437139/ 10:31 : Ioannidis, J. “Why Most Published Research Findings Are False”. PLOS Medicine. 30 Aug 2005. http://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.0020124 11:31 : Callaway, E. “Beat it, impact factor! Publishing elite turns against controversial metric”. Nature. 8 Jul 2016. http://www.nature.com/news/beat-it-impact-factor-publishing-elite-turns-against-controversial-metric-1.20224#/b1 11:42 : “Impact Factor Statement”. The European Association of Science Editors. http://www.ease.org.uk/impact-factor-statement