RT Journal Article SR Electronic T1 Rare adverse events in clinical trials: understanding the rule of three JF BMJ Evidence-Based Medicine JO BMJ EBM FD BMJ Publishing Group Ltd SP 6 OP 6 DO 10.1136/ebmed-2017-110885 VO 23 IS 1 A1 Igho J Onakpoya YR 2018 UL http://ebm.bmj.com/content/23/1/6.abstract AB