RT Journal Article SR Electronic T1 A comprehensive approach needed to address regional variation JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP E840 OP E840 DO 10.1503/cmaj.733075 VO 189 IS 24 A1 Gardner, Charles A1 Simon, Lisa A1 Sutcliffe, Penny A1 Loh, Lawrence C. A1 Noseworthy, Lynn A1 Salvaterra, Rosana (Pellizzari) A1 Young-Hoon, Kit YR 2017 UL http://www.cmaj.ca/content/189/24/E840.abstract AB