Article Text
Abstract
Introduction Lifestyle and job-related conditions (LS and JRC) are recognised cardiovascular disease (CVD) risk factors, but their prognostic utility remains to be established. We investigated the discrimination ability at 10 years of LS and JRC in a Northern Italian working male population.
Methods n=2532 men, 35–64 years, CVD-free and employed at the time of recruitment (1989–1996) in either the MONICA-Brianza and PAMELA (population-based) or the SEMM (factory-based) cohorts, were available for the analyses. The following LS and JRC were ascertained using standardised procedures: smoking (current vs non-current); alcohol intake (drinks/day; 1–3 drinks as reference); habitual occupational and sport physical activity (PA; the Baecke questionnaire); job strain (high vs non-high; Job Content Questionnaire) and BMI, from measured height and weight. Workers were followed-up (median 14 years) until first major coronary event or ischaemic stroke, fatal or non-fatal. Discrimination ability was estimated as the Area Under the ROC-Curve (AUC) for a Cox model with LS and JRC satisfying the Akaike Information Criterion for the selection of candidate predictors, and contrasted to the AUC from a model including blood lipids, blood pressure, smoking and diabetes.
Result n=162 events occurred during follow-up (10 year risk: 4.3%). BMI was not associated with the endpoint. The risk factors meeting the AI Criterion were: smoking (Hazard Ratio=2.49, 95% CI: 1.81 to 3.42); alcohol intake (abstainers: HR=1.52, 1.03–2.23; 6+drinks/day: HR=1.81, 1.11–2.95); job strain (HR=1.39, 0.98–1.97); combined sport and occupational PA (p=0.02), as the HRs for sport PA changed between workers at low (HR=0.42) and intense (HR=1.55) occupational PA (interaction test p=0.001). The LS and JRC model had the same discrimination (AUC=0.75; 95% CI: 0.70 to 0.78) than the model with clinical and biological risk factors (AUC=0.75); this finding was consistent across the occupational classes.
Discussion Our results support the potential of primary prevention interventions at the workplace based on promoting healthier lifestyles and on improving job-related risk factors, to reduce CVD risk among workers.