Department of Occupational and Environmental Medicine, Bispebjerg University Hospital, Copenhagen, Denmark.
Department of Cardiology, Bispebjerg University Hospital, Copenhagen, Denmark.
Occup Environ Med. 2018 Dec;75(12):890-897. doi: 10.1136/oemed-2018-104991. Epub 2018 Sep 1.
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.
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.
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.
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.
在基于注册的职业健康研究中，有关生活方式因素的信息通常不可用。因此，本研究的目的是开发性别、年龄和日历时间特异性的职业暴露矩阵（JEM），针对五个选定的生活方式特征，跨越不同职业群体，作为基于注册的研究中生活方式调整的工具。
我们结合并协调了丹麦几项调查中关于生活方式的问卷调查和访谈数据，这些数据涵盖了 1981 年至 2013 年期间登记在全国性基于注册的丹麦职业队列中的 264054 名员工。我们使用混合模型为每个四位 DISCO 代码（丹麦版本的国际标准职业分类 ISCO-88）的水平建模特定生活方式的概率，以年龄和性别为固定效应，并根据职业内类内相关系数（ICC）和暴露水平百分位数比值评估不同时期（1981 年至 2013 年）的变化。
ICC 总体较低（0.26%-7.05%），因为组内变异相对于职业间变异较大，但跨职业而言，特定日历时期的最高和最低预测水平之间的比值范围为 1.2 至 6.9，95%/1%和 75%/5%的百分位数比值范围分别为 1.1-2.8 和 1.1-1.6，这表明一些生活方式暴露和一些职业存在显著差异。
生活方式 JEM 可能是基于注册的职业健康研究中控制与生活方式相关混杂因素的有用工具，在这些研究中，缺乏个人生活方式因素的信息可能会影响内部有效性。
