Objectives Information about lifestyle factors in register-based occupational health studies is often not available. The objective of this study was therefore to develop gender, age and calendar-time specific job-exposure matrices (JEMs) addressing five selected lifestyle characteristics across job groups as a tool for lifestyle adjustment in register-based studies.
Methods We combined and harmonised questionnaire and interview data on lifestyle from several Danish surveys in the time period 1981–2013 for 264 054 employees registered with a DISCO-88 code (the Danish version of International Standard Classification of Occupations (ISCO)-88) in a nationwide register-based Danish Occupational Cohort. We modelled the probability of specified lifestyles in mixed models for each level of the four-digit DISCO code with age and sex as fixed effects and assessed variation in terms of intraclass correlation coefficients (ICCs) and exposure-level percentile ratios across jobs for six different time periods from 1981 through 2013.
Results The ICCs were overall low (0.26%–7.05%) as the within-job group variation was large relative to the between job group variation, but across jobs the calendar period-specific ratios between highest and lowest predicted levels were ranging from 1.2 to 6.9, and for the 95%/1% and the 75%/5% percentile ratios ranges were 1.1–2.8 and 1.1–1.6, respectively, thus indicating substantial contrast for some lifestyle exposures and some occupations.
Conclusions The lifestyle JEMs may prove a useful tool for control of lifestyle-related confounding in register-based occupational health studies where lacking information on individual lifestyle factors may compromise internal validity.
- cohort study
This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.
Statistics from Altmetric.com
Contributors JPB, SBP and EMF conceived and designed the study. SBP and EMF analysed the data. SBP wrote the first draft which was revised by JPB. All authors contributed to the writing of the manuscript, and final version was approved by all authors.
Funding The study was funded by the Danish Working Environment Research Fund (43-2014-03/20140016763).
Competing interests None declared.
Patient consent Not required.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement All data are stored at Statistics Denmark. Researcher can get online access to data, also from abroad, through contact the correspondng author who can apply for permission.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.