RT Journal Article SR Electronic T1 Opioids and chronic pain JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 74 OP 74 DO 10.1503/cmaj.112-2003 VO 184 IS 1 A1 Kahan, Meldon M. YR 2012 UL http://www.cmaj.ca/content/184/1/74.1.abstract