RT Journal Article SR Electronic T1 Increasing nurse staffing levels in cardiac surgery centres appears to be a cost effective patient safety intervention JF Evidence Based Nursing JO Evid Based Nurs FD BMJ Publishing Group Ltd and RCN Publishing Company Ltd SP 102 OP 102 DO 10.1136/ebn1096 VO 13 IS 4 A1 Patricia A Hickey YR 2010 UL http://ebn.bmj.com/content/13/4/102.abstract AB