RT Journal Article SR Electronic T1 Job-exposure matrices addressing lifestyle to be applied in register-based occupational health studies JF Occupational and Environmental Medicine JO Occup Environ Med FD BMJ Publishing Group Ltd SP 890 OP 897 DO 10.1136/oemed-2018-104991 VO 75 IS 12 A1 Sesilje Bondo Petersen A1 Esben Meulengracht Flachs A1 Eva Irene Bossano Prescott A1 Anne Tjønneland A1 Merete Osler A1 Ingelise Andersen A1 Knud Juel A1 Esben Budz-Jørgensen A1 Henrik A Kolstad A1 Vivi Schlünssen A1 Jens Peter Bonde YR 2018 UL http://oem.bmj.com/content/75/12/890.abstract AB 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.