TY - JOUR T1 - Glossary JF - Evidence Based Nursing JO - Evid Based Nurs SP - 62a LP - 62a DO - 10.1136/ebn.9.2.62a VL - 9 IS - 2 A2 - , Y1 - 2006/04/01 UR - http://ebn.bmj.com/content/9/2/62a.abstract N2 - Blinding (masking): in an experimental study, refers to whether patients, clinicians providing an intervention, people assessing outcomes, and/or data analysts were aware or unaware of the group to which patients were assigned. In the methods section of Evidence-Based Nursing abstracts of treatment studies, the study is identified as blinded, with specification of who was blinded; unblinded, if all parties were aware of patients’ group assignments; or unclear if the authors did not report or provide us with an indication of who was aware or unaware of patients’ group assignments.Cluster randomisation1: randomisation of groups of people rather than individuals; this approach is often used to avoid “contamination” when the way in which people in one group are treated or assessed is likely to modify the treatment or assessment of people in other groups.Concealment of randomisation: concealment of randomisation is specified in the methods section of Evidence-Based Nursing abstracts of treatment studies as follows: allocation concealed (deemed to have taken adequate measures to conceal allocation to study group assignments from those responsible for assessing patients for entry in the trial [ie, … ER -