A systematic review of studies in the contributions of the work environment to ischaemic heart disease development

Background: There is need for an updated systematic review of associations between occupational exposures and ischaemic heart disease (IHD), using the GRADE system. Methods: Inclusion criteria: (i) publication in English in peer-reviewed journal between 1985 and 2014, (ii) quantified relationship between occupational exposure (psychosocial, organizational, physical and other ergonomic job factors) and IHD outcome, (iii) cohort studies with at least 1000 participants or comparable case-control studies with at least 50 + 50 participants, (iv) assessments of exposure and outcome at baseline as well as at follow-up and (v) gender and age analysis. Relevance and quality were assessed using predefined criteria. Level of evidence was then assessed using the GRADE system. Consistency of findings was examined for a number of confounders. Possible publication bias was discussed. Results: Ninety-six articles of high or medium high scientific quality were finally included. There was moderately strong evidence (grade 3 out of 4) for a relationship between job strain and small decision latitude on one hand and IHD incidence on the other hand. Limited evidence (grade 2) was found for iso-strain, pressing work, effort-reward imbalance, low support, lack of justice, lack of skill discretion, insecure employment, night work, long working week and noise in relation to IHD. No difference between men and women with regard to the effect of adverse job conditions on IHD incidence. Conclusions: There is scientific evidence that employees, both men and women, who report specific occupational exposures, such as low decision latitude, job strain or noise, have an increased incidence of IHD.