Cargando…

Assessing the reporting of categorised quantitative variables in observational epidemiological studies

BACKGROUND: One aspect to consider when reporting results of observational studies in epidemiology is how quantitative risk factors are analysed. The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines recommend that researchers describe how they handle quantitat...

Descripción completa

Detalles Bibliográficos
Autores principales: Mabikwa, Onkabetse V., Greenwood, Darren C., Baxter, Paul D., Fleming, Sarah J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5348776/
https://www.ncbi.nlm.nih.gov/pubmed/28288628
http://dx.doi.org/10.1186/s12913-017-2137-z
_version_ 1782514319478489088
author Mabikwa, Onkabetse V.
Greenwood, Darren C.
Baxter, Paul D.
Fleming, Sarah J.
author_facet Mabikwa, Onkabetse V.
Greenwood, Darren C.
Baxter, Paul D.
Fleming, Sarah J.
author_sort Mabikwa, Onkabetse V.
collection PubMed
description BACKGROUND: One aspect to consider when reporting results of observational studies in epidemiology is how quantitative risk factors are analysed. The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) 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. 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 remain unknown in most articles. The existing STROBE guidelines could provide stronger recommendations on reporting quantitative risk factors in epidemiology. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12913-017-2137-z) contains supplementary material, which is available to authorized users.
format Online
Article
Text
id pubmed-5348776
institution National Center for Biotechnology Information
language English
publishDate 2017
publisher BioMed Central
record_format MEDLINE/PubMed
spelling pubmed-53487762017-03-14 Assessing the reporting of categorised quantitative variables in observational epidemiological studies Mabikwa, Onkabetse V. Greenwood, Darren C. Baxter, Paul D. Fleming, Sarah J. BMC Health Serv Res Research Article BACKGROUND: One aspect to consider when reporting results of observational studies in epidemiology is how quantitative risk factors are analysed. The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) 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. 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 remain unknown in most articles. The existing STROBE guidelines could provide stronger recommendations on reporting quantitative risk factors in epidemiology. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12913-017-2137-z) contains supplementary material, which is available to authorized users. BioMed Central 2017-03-14 /pmc/articles/PMC5348776/ /pubmed/28288628 http://dx.doi.org/10.1186/s12913-017-2137-z Text en © The Author(s). 2017 Open AccessThis 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.
spellingShingle Research Article
Mabikwa, Onkabetse V.
Greenwood, Darren C.
Baxter, Paul D.
Fleming, Sarah J.
Assessing the reporting of categorised quantitative variables in observational epidemiological studies
title Assessing the reporting of categorised quantitative variables in observational epidemiological studies
title_full Assessing the reporting of categorised quantitative variables in observational epidemiological studies
title_fullStr Assessing the reporting of categorised quantitative variables in observational epidemiological studies
title_full_unstemmed Assessing the reporting of categorised quantitative variables in observational epidemiological studies
title_short Assessing the reporting of categorised quantitative variables in observational epidemiological studies
title_sort assessing the reporting of categorised quantitative variables in observational epidemiological studies
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5348776/
https://www.ncbi.nlm.nih.gov/pubmed/28288628
http://dx.doi.org/10.1186/s12913-017-2137-z
work_keys_str_mv AT mabikwaonkabetsev assessingthereportingofcategorisedquantitativevariablesinobservationalepidemiologicalstudies
AT greenwooddarrenc assessingthereportingofcategorisedquantitativevariablesinobservationalepidemiologicalstudies
AT baxterpauld assessingthereportingofcategorisedquantitativevariablesinobservationalepidemiologicalstudies
AT flemingsarahj assessingthereportingofcategorisedquantitativevariablesinobservationalepidemiologicalstudies