Mabikwa, OV, Greenwood, DC orcid.org/0000-0001-7035-3096, Baxter, PD orcid.org/0000-0003-2699-3103 et al. (1 more author) (2017) Assessing the reporting of categorised quantitative variables in observational epidemiological studies. BMC Health Services Research, 17 (1). ISSN 1472-6963
Abstract
Background One aspect to consider when reporting results of observational studies in epidemiology is how quantitative risk factors are analysed. The STROBE guidelines recommend that researchers describe how they handle quantitative variables when analysing data. For categorised quantitative variables, the authors are required to provide reasons and justifications informing their practice. We investigated and assessed the practices and reporting of categorised quantitative variables in epidemiology. Methods The assessment was based on five medical journals that publish epidemiological research. Observational studies published between April and June 2015 and investigating the relationships between quantitative exposures (or risk factors) and the outcomes were considered for assessment. A standard form was used to collect the data, and the reporting patterns amongst eligible studies were quantified and described in the results section. Results Out of 61 articles assessed for eligibility, 23 observational studies were included in the assessment. Categorisation of quantitative exposures occurred in 61% of these studies and reasons informing the practice were rarely provided. Only one article explained the choice of categorisation in the analysis. Transformation of quantitative exposures into four or five groups was common and dominant amongst studies using equally spaced categories. Dichotomisation was not popular; the practice featured in one article. Overall, the majority (86%) of the studies preferred ordered or arbitrary group categories. Other criterions used to decide categorical boundaries were based on established guidelines such as consensus statements and WHO standards. Conclusion Categorisation of continuous variables remains a dominant practice in epidemiological studies. The reasons informing the practice of categorisation within published work are limited and remains unknown in most articles. The existing STROBE guidelines could provide stronger recommendations on reporting quantitative risk factors in epidemiology. Keywords Categorisation - Quantitative or continuous variables - STOBE guidelines – Observational studies
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © The Author(s). 2017. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated |
Keywords: | Categorisation; Quantitative or continuous variables; STOBE guidelines; Observational studies |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Medicine and Health (Leeds) > School of Medicine (Leeds) > Leeds Institute of Genetics, Health and Therapeutics (LIGHT) > Division of Epidemiology & Biostatistics (Leeds) The University of Leeds > Faculty of Medicine and Health (Leeds) > Institute of Molecular Medicine (LIMM) (Leeds) > Section of Epidemiology and Biostatistics (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 27 Feb 2017 15:08 |
Last Modified: | 23 Jun 2023 22:24 |
Published Version: | https://doi.org/10.1186/s12913-017-2137-z |
Status: | Published |
Publisher: | BioMed Central |
Identification Number: | 10.1186/s12913-017-2137-z |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:112805 |