RT Journal Article SR Electronic T1 The contribution of major risk factors and job strain to occupational class differences in coronary heart disease incidence: the MONICA Brianza and PAMELA population-based cohorts JF Occupational and Environmental Medicine JO Occup Environ Med FD BMJ Publishing Group Ltd SP 717 OP 722 DO 10.1136/oem.2010.060822 VO 68 IS 10 A1 Ferrario, Marco M A1 Veronesi, Giovanni A1 Chambless, Lloyd E A1 Sega, Roberto A1 Fornari, Carla A1 Bonzini, Matteo A1 Cesana, Giancarlo YR 2011 UL http://oem.bmj.com/content/68/10/717.abstract AB Objectives We investigated the contribution of major coronary heart disease (CHD) risk factors and job strain to occupational class differences in CHD incidence in a pooled-cohort prospective study in northern Italy.Methods 2964 men aged 25–74 from four northern Italian population-based cohorts were investigated at baseline and followed for first fatal or non-fatal CHD event (171 events). Standardised procedures were used for baseline risk factor measurements, follow-up and validation of CHD events. Four occupational classes were derived from the Erikson–Goldthorpe–Portocarero social class scheme: higher and lower professionals and administrators, non-manual workers, skilled and unskilled manual workers, and the self-employed. HRs were estimated with Cox models.Results Among CHD-free subjects, with non-manual workers as the reference group, age-adjusted excess risks were found for professionals and administrators (+84%, p=0.02), the self-employed (+72%, p=0.04) and manual workers (+63%, p=0.04). The relationship was consistent across different CHD diagnostic categories. Adjusting for major risk factors only slightly reduced the reported excess risks. In a sub-sample of currently employed subjects, adjusting for major risk factors, sport physical activity and job strain reduced the excess risk for manual workers (relative change = −71.4%) but did not substantially modify the excess risks of professionals and administrators and the self-employed.Conclusions In our study, we found higher CHD incidence rates for manual workers, professionals and administrators, and the self-employed, compared to non-manual workers. When the entire spectrum of job categories is considered, the job strain model helped explain the CHD excess risk for manual workers but not for other occupational classes.