Kivimäki M, Theorell T, Westerlund H, Vahtera J, Alfredsson L
International Institute for Society and Health, Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London WC1E 6BT, UK.
J Epidemiol Community Health. 2008 Apr;62(4):372-4. doi: 10.1136/jech.2007.063578.
Evidence on the association between job strain and ischaemic disease is mixed. This study examined whether including older age individuals in a cohort used to assess job strain attenuates findings towards the null.
A prospective cohort study with baseline screening in 1992-5. A follow-up for ischaemic disease until 2003 was based on linkages to national registries. Ischaemic disease was corroborated by objective criteria (hospitalisation as a result of acute myocardial infarction, unstable angina or ischaemic stroke; or death from ischaemic heart disease, cardiac arrest or ischaemic stroke).
3160 male employees aged 19-65 years without pre-existing or current ischaemic disease.
93 cases of incident ischaemic disease were recorded. In the 19-55 year age group, the participants with job strain had a 1.76 (95% CI 1.05 to 2.95) times higher age-adjusted risk of incident ischaemic disease than those free of strain. Further adjustment for conventional cardiovascular risk factors had little effect on this association, but the impact of job strain was reduced by 70% to non-significant after the inclusion of employees older than 55 years in the cohort (hazard ratio 1.22, 95% CI 0.75 to 1.96).
Including older employees in a cohort may dilute the effect of job strain on cardiovascular disease and is a potential reason for inconsistent findings in previous studies.
关于工作压力与缺血性疾病之间关联的证据并不一致。本研究探讨了在用于评估工作压力的队列中纳入老年个体是否会使研究结果趋向于无效。
一项前瞻性队列研究，于1992 - 1995年进行基线筛查。基于与国家登记处的关联，对缺血性疾病进行随访至2003年。缺血性疾病通过客观标准得到证实（因急性心肌梗死、不稳定型心绞痛或缺血性中风住院；或死于缺血性心脏病、心脏骤停或缺血性中风）。
3160名年龄在19 - 65岁之间、无既往或当前缺血性疾病的男性员工。
记录到93例新发缺血性疾病病例。在19 - 55岁年龄组中，有工作压力的参与者发生缺血性疾病的年龄调整风险比无压力者高1.76倍（95%置信区间为1.05至2.95）。对传统心血管危险因素进行进一步调整对这种关联影响不大，但在队列中纳入55岁以上员工后，工作压力的影响降低了70%，变为不显著（风险比为1.22，95%置信区间为0.75至1.96）。
在队列中纳入老年员工可能会稀释工作压力对心血管疾病的影响，这是先前研究结果不一致的一个潜在原因。
