TY - JOUR T1 - Selection bias JF - Canadian Medical Association Journal JO - CMAJ SP - E673 LP - E673 DO - 10.1503/cmaj.732958 VL - 189 IS - 18 AU - Michael S. Jansz Y1 - 2017/05/08 UR - http://www.cmaj.ca/content/189/18/E673.abstract N2 - ER -