RT Journal Article SR Electronic T1 How to attribute causality in quality improvement: lessons from epidemiology JF BMJ Quality & Safety JO BMJ Qual Saf FD BMJ Publishing Group Ltd SP 933 OP 937 DO 10.1136/bmjqs-2017-006756 VO 26 IS 11 A1 Poots, Alan J A1 Reed, Julie E A1 Woodcock, Thomas A1 Bell, Derek A1 Goldmann, Don YR 2017 UL http://qualitysafety.bmj.com/content/26/11/933.abstract AB