RT Journal Article SR Electronic T1 New Canadian guidance on opioid use for chronic pain: necessary but not sufficient JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP E650 OP E651 DO 10.1503/cmaj.170431 VO 189 IS 18 A1 Furlan, Andrea D. A1 Williamson, Owen D. YR 2017 UL http://www.cmaj.ca/content/189/18/E650.abstract