RT Journal Article SR Electronic T1 What we still don’t know about treating chronic noncancer pain with opioids JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 881 OP 882 DO 10.1503/cmaj.100548 VO 182 IS 9 A1 Roger Chou YR 2010 UL http://www.cmaj.ca/content/182/9/881.abstract