How Current Are Leading Evidence-Based Medical Textbooks? An Analytic Survey of Four Online Textbooks

Rebecca Jeffery   ^{1 *} , B.Sc (Hons) ;   Tamara Navarro   ^{1 *} , MLIS, MEd ;   Cynthia Lokker   ^{1 *} , PhD ;   R Brian Haynes   ^{1 *} , MD, PhD ;   Nancy L Wilczynski   ^{1 *} , PhD ;   George Farjou   ^{1 *} , B.Sc (Hons)

¹ Health Information Research Unit, Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada

*all authors contributed equally