RT Journal Article SR Electronic T1 Opioids versus non-opioids for chronic musculoskeletal pain JF Drug and Therapeutics Bulletin JO Drug Ther Bull FD BMJ Publishing Group Ltd SP 50 OP 51 DO 10.1136/dtb.2018.5.0617 VO 56 IS 5 YR 2018 UL http://dtb.bmj.com/content/56/5/50.2.abstract AB