Workplace and age associated with severity of occupational injuries and cardiovascular emergencies: a nationwide study in Japan

Background Among working-age populations globally, occupational injuries and workplace cardiovascular emergencies remain major contributors to morbidity and mortality. This study examined the associations between workplace settings, age groups, and the severity of occupational injuries and cardiovascular events. Methods We conducted a nationwide retrospective registry-based observational study using emergency medical services data from Japan, including 454 043 working-age individuals recorded in 2021–2023. Workplace settings (office, indoor worksite, factory, outdoor worksite, construction, agriculture, and others) and age groups were analysed in relation to event severity, categorized as non-life-threatening or life-threatening. Multivariable regression models estimated the associations, and workplace–age interactions were assessed. Results Compared with office settings, all other workplaces were associated with higher odds of life-threatening injuries, particularly agriculture and construction. Increasing age groups were progressively associated with greater injury severity. The workplace setting was associated with the severity of stroke and ischaemic heart disease, particularly in uncontrolled outdoor environments. Stroke severity was elevated in those aged 45–59 and 60–69 years, while all older age groups were associated with severe ischaemic heart disease. Workplace–age interactions were significant only for occupational injuries. Conclusions Workplace and age were interactively and independently associated with the severity of occupational injuries and cardiovascular emergencies.