title: Data extraction for complex meta-analysis (DECiMAL) guide.
abstract: As more complex meta-analytical techniques such as network and multivariate meta-analyses become increasingly common, further pressures are placed on reviewers to extract data in a systematic and consistent manner. Failing to do this appropriately wastes time, resources and jeopardises accuracy. This guide (data extraction for complex meta-analysis (DECiMAL)) suggests a number of points to consider when collecting data, primarily aimed at systematic reviewers preparing data for meta-analysis. Network meta-analysis (NMA), multiple outcomes analysis and analysis combining different types of data are considered in a manner that can be useful across a range of data collection programmes. The guide has been shown to be both easy to learn and useful in a small pilot study.
authors.affiliation: National Guideline Alliance, Royal College of Obstetricians and Gynaecologists, London, UK. hpedder@rcog.org.uk.
authors.forename: Hugo
authors.initials: H
authors.lastname: Pedder
authors.affiliation: Evidera Inc., London, UK.
authors.forename: Grammati
authors.initials: G
authors.lastname: Sarri
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol, UK.
authors.forename: Edna
authors.initials: E
authors.lastname: Keeney
authors.affiliation: National Guideline Alliance, Royal College of Obstetricians and Gynaecologists, London, UK.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Nunes
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol, UK.
authors.forename: Sofia
authors.initials: S
authors.lastname: Dias
mesh_terms: D003625:Data Collection / Q000379:methods*; D003627:Data Interpretation, Statistical; D015201:Meta-Analysis as Topic; D010865:Pilot Projects; D015203:Reproducibility of Results; D012107:Research Design; D012196:Review Literature as Topic
keywords: Analysis; Data; Extraction; Guide; Meta-analysis; Multivariate; Network; Review