Cargando…

Information bias of social gradients in sickness absence: a comparison of self-report data in the Norwegian Mother and Child Cohort Study (MoBa) and data in national registries

BACKGROUND: Measurement error in self-report questionnaires is a common source of bias in epidemiologic studies. The study aim was to assess information bias of the educational gradient in sickness absence among participants in the Norwegian Mother and Child Cohort Study (MoBa), comparing self-repor...

Descripción completa

Detalles Bibliográficos
Autores principales: Kristensen, Petter, Corbett, Karina, Mohn, Ferdinand A., Hanvold, Therese N., Mehlum, Ingrid S.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6245919/
https://www.ncbi.nlm.nih.gov/pubmed/30453919
http://dx.doi.org/10.1186/s12889-018-6208-9
_version_ 1783372344515887104
author Kristensen, Petter
Corbett, Karina
Mohn, Ferdinand A.
Hanvold, Therese N.
Mehlum, Ingrid S.
author_facet Kristensen, Petter
Corbett, Karina
Mohn, Ferdinand A.
Hanvold, Therese N.
Mehlum, Ingrid S.
author_sort Kristensen, Petter
collection PubMed
description BACKGROUND: Measurement error in self-report questionnaires is a common source of bias in epidemiologic studies. The study aim was to assess information bias of the educational gradient in sickness absence among participants in the Norwegian Mother and Child Cohort Study (MoBa), comparing self-report data with national register data. METHODS: MoBa is a national prospective cohort study. The present study included 49,637 participants, born 1967–1976, who gave birth 2000–2009. The highest completed education level was recorded in categories and as educational years. Sickness absence was defined as one or more spell lasting more than 16 days between pregnancy weeks 13 and 30. We computed sickness absence risk in mid-pregnancy in strata of education level. Associations between completed educational years and sickness absence were estimated as risk differences in binomial regression and compared between self-report and register data. In additional analyses, we aimed to explain discrepancies between estimates from the two data sources. RESULTS: The overall registry-based sickness absence risk was 0.478 and decreased for increasingly higher education in a consistent fashion, yielding an additive risk difference in association with one additional education year of − 0.032 (95% confidence interval − 0.035 to − 0.030). The self-report risk was lower (0.307) with a corresponding risk difference of only − 0.013 (95% confidence interval − 0.015 to − 0.011). The main explanation of the lower risk difference in the self-report data was a tendency for mothers in low education categories to omit reporting sickness absence in the questionnaire. CONCLUSIONS: A plausible explanation for the biased self-report association is complexity of the sickness absence question and a resulting educational gradient in non-response. As shown for sickness absence in mid-pregnancy in the present study, national registries could be a preferred alternative to self-report questionnaires. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12889-018-6208-9) contains supplementary material, which is available to authorized users.
format Online
Article
Text
id pubmed-6245919
institution National Center for Biotechnology Information
language English
publishDate 2018
publisher BioMed Central
record_format MEDLINE/PubMed
spelling pubmed-62459192018-11-26 Information bias of social gradients in sickness absence: a comparison of self-report data in the Norwegian Mother and Child Cohort Study (MoBa) and data in national registries Kristensen, Petter Corbett, Karina Mohn, Ferdinand A. Hanvold, Therese N. Mehlum, Ingrid S. BMC Public Health Research Article BACKGROUND: Measurement error in self-report questionnaires is a common source of bias in epidemiologic studies. The study aim was to assess information bias of the educational gradient in sickness absence among participants in the Norwegian Mother and Child Cohort Study (MoBa), comparing self-report data with national register data. METHODS: MoBa is a national prospective cohort study. The present study included 49,637 participants, born 1967–1976, who gave birth 2000–2009. The highest completed education level was recorded in categories and as educational years. Sickness absence was defined as one or more spell lasting more than 16 days between pregnancy weeks 13 and 30. We computed sickness absence risk in mid-pregnancy in strata of education level. Associations between completed educational years and sickness absence were estimated as risk differences in binomial regression and compared between self-report and register data. In additional analyses, we aimed to explain discrepancies between estimates from the two data sources. RESULTS: The overall registry-based sickness absence risk was 0.478 and decreased for increasingly higher education in a consistent fashion, yielding an additive risk difference in association with one additional education year of − 0.032 (95% confidence interval − 0.035 to − 0.030). The self-report risk was lower (0.307) with a corresponding risk difference of only − 0.013 (95% confidence interval − 0.015 to − 0.011). The main explanation of the lower risk difference in the self-report data was a tendency for mothers in low education categories to omit reporting sickness absence in the questionnaire. CONCLUSIONS: A plausible explanation for the biased self-report association is complexity of the sickness absence question and a resulting educational gradient in non-response. As shown for sickness absence in mid-pregnancy in the present study, national registries could be a preferred alternative to self-report questionnaires. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12889-018-6208-9) contains supplementary material, which is available to authorized users. BioMed Central 2018-11-20 /pmc/articles/PMC6245919/ /pubmed/30453919 http://dx.doi.org/10.1186/s12889-018-6208-9 Text en © The Author(s). 2018 Open Access 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.
spellingShingle Research Article
Kristensen, Petter
Corbett, Karina
Mohn, Ferdinand A.
Hanvold, Therese N.
Mehlum, Ingrid S.
Information bias of social gradients in sickness absence: a comparison of self-report data in the Norwegian Mother and Child Cohort Study (MoBa) and data in national registries
title Information bias of social gradients in sickness absence: a comparison of self-report data in the Norwegian Mother and Child Cohort Study (MoBa) and data in national registries
title_full Information bias of social gradients in sickness absence: a comparison of self-report data in the Norwegian Mother and Child Cohort Study (MoBa) and data in national registries
title_fullStr Information bias of social gradients in sickness absence: a comparison of self-report data in the Norwegian Mother and Child Cohort Study (MoBa) and data in national registries
title_full_unstemmed Information bias of social gradients in sickness absence: a comparison of self-report data in the Norwegian Mother and Child Cohort Study (MoBa) and data in national registries
title_short Information bias of social gradients in sickness absence: a comparison of self-report data in the Norwegian Mother and Child Cohort Study (MoBa) and data in national registries
title_sort information bias of social gradients in sickness absence: a comparison of self-report data in the norwegian mother and child cohort study (moba) and data in national registries
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6245919/
https://www.ncbi.nlm.nih.gov/pubmed/30453919
http://dx.doi.org/10.1186/s12889-018-6208-9
work_keys_str_mv AT kristensenpetter informationbiasofsocialgradientsinsicknessabsenceacomparisonofselfreportdatainthenorwegianmotherandchildcohortstudymobaanddatainnationalregistries
AT corbettkarina informationbiasofsocialgradientsinsicknessabsenceacomparisonofselfreportdatainthenorwegianmotherandchildcohortstudymobaanddatainnationalregistries
AT mohnferdinanda informationbiasofsocialgradientsinsicknessabsenceacomparisonofselfreportdatainthenorwegianmotherandchildcohortstudymobaanddatainnationalregistries
AT hanvoldtheresen informationbiasofsocialgradientsinsicknessabsenceacomparisonofselfreportdatainthenorwegianmotherandchildcohortstudymobaanddatainnationalregistries
AT mehlumingrids informationbiasofsocialgradientsinsicknessabsenceacomparisonofselfreportdatainthenorwegianmotherandchildcohortstudymobaanddatainnationalregistries