RT Journal Article SR Electronic T1 Roles of nurse practitioners and physician assistants in medicine still under debate JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP E203 OP E204 DO 10.1503/cmaj.109-5708 VO 191 IS 7 A1 Brian Owens YR 2019 UL http://www.cmaj.ca/content/191/7/E203.abstract