RT Journal Article SR Electronic T1 Value of small sample sizes in rapid-cycle quality improvement projects 2: assessing fidelity of implementation for improvement interventions JF BMJ Quality & Safety JO BMJ Qual Saf FD BMJ Publishing Group Ltd SP 61 OP 65 DO 10.1136/bmjqs-2017-006963 VO 27 IS 1 A1 Etchells, Edward A1 Woodcock, Thomas YR 2018 UL http://qualitysafety.bmj.com/content/27/1/61.abstract AB