Newcastle–Ottawa scale

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In statistics, the Newcastle–Ottawa scale is a tool used for assessing the quality of non-randomized studies included in a systematic review and/or meta-analyses. Using the tool, each study is judged on eight items, categorized into three groups: the selection of the study groups; the comparability of the groups; and the ascertainment of either the exposure or outcome of interest for case-control or cohort studies respectively. Stars awarded for each quality item serve as a quick visual assessment. Stars are awarded such that the highest quality studies are awarded up to nine stars. The method was developed as a collaboration between the Universities of Newcastle, Australia and Ottawa, Canada using a Delphi process to define variables for data extraction. The scale was then tested on systematic reviews and further refined.[1] Separate tools were developed for cohort and case–control studies.

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  1. ^ Deeks JJ, Dinnes J, D'Amico R, Sowden AJ, Sakarovitch C, Song F, et al.Evaluating non-randomised intervention studies. Health Technol Assess 2003;7(27)