RT Journal Article SR Electronic T1 Assessing allocation concealment and blinding in randomised controlled trials: why bother? JF Evidence Based Nursing JO Evid Based Nurs FD BMJ Publishing Group Ltd and RCN Publishing Company Ltd SP 4 OP 6 DO 10.1136/ebn.4.1.4 VO 4 IS 1 A1 Kenneth F Schulz YR 2001 UL http://ebn.bmj.com/content/4/1/4.abstract AB