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.Electronic supplementary materialThe online version of this article (doi:10.1186/s13643-016-0368-4) contains supplementary material, which is available to authorized users.

Clinical efficacy of bronchodilators in equine asthma: Looking for minimal important difference

“…Pharmacological interventions for treating asthma are rarely supported by strong certainty or high‐quality evidence and clinical trials are often underpowered . This study provides evidence from the quantitative synthesis of clinical trials in agreement with the current guidelines and recommendations for improving the transparency, accuracy, completeness and frequency of documented meta‐analysis protocols, namely PRISMA‐P, PROSPERO, GRADE and DECiMAL . Thus, our findings can be ranked at the highest level of the current hierarchy of evidence .…”

“…Data from included studies were extracted and checked for study characteristics, enrolled animals with age and body weight, drugs and regimen of administration, clinical score, induction of clinical signs, inhaler devices and spacers, lung function (maximum change in transpulmonary pressure [ΔPpl max ], pulmonary resistance [R L ], dynamic lung compliance [C dyn ]) and Jadad score. Data were extracted at the different time points available in the studies in agreement with DECiMAL recommendations . When needed, mean and standard deviation (s.d.)…”

Vasomotor symptoms resulting from natural menopause: a systematic review and network meta‐analysis of treatment effects from the National Institute for Health and Care Excellence guideline on menopause

“…Data were double extracted in a structured form, using a guide developed by the authors for Data Extraction for Complex Meta‐anALysis (DECiMAL), independently by two reviewers . Discrepancies in data extraction were addressed by a senior reviewer who resolved any conflicts.…”

Change in Format, Register and Narration Style in the Biomedical Literature: A 1948 Example

“…Although this paper flows smoothly when read, it would not be easy to replicate its experiments because of the lack of those minute details that mercilessly break down narration and make the modern Materials and Method sections so typically dry and unpleasant to read and yet so essential, when those details are needed. Furthermore, it must be admitted that is not easy to compare data and it is not easy to extract data for metanalysis purposes [92], when expressed narratively. Considering the staggering abundance of available scientific literature for any field of science and any specialty in the biomedical area, these limits cannot be overlooked.…”