Introduction Long working hours and rotating shifts are risk factors for cardiovascular disease. National policies and corporate actions play an important role in sound working hours and shifts. Imbalanced rotation speed and working hours may double the burden of cardiovascular disease. We investigated the incidence of work-related cardiovascular disease before and after government relaxed disease recognition criteria in Taiwan. We further used a traditional manufacturing factory as an example to analyze the association between corporate health promotion activities and workers’ cardiovascular disease risks.

Methods At the national level, we collected data on the number of work-related cardiovascular disease and average working hours per month before and after policy changes. At the corporate level, we collected data on shift types, working hours, health promotion activities, and 10-year risk of manifesting clinical cardiovascular disease. Our statistical analyses included applying mixed-effect models, a mediation analysis, and a generalized estimating equation.

Results The relaxation of national criteria for recognizing work-related cardiovascular disease has resulted in a 2.5-fold increase in the incidence rate. This effect was mediated by working hours. Our case study showed workers who worked 12 hours per shift had a higher risk of cardiovascular disease than those who worked 8 hours per shift. Workers who needed to rotate shifts and spent more time on each shift had a higher risk of cardiovascular disease than those who shifted but spent less time on each shift. Workers who participated in health promotion activities had a lower risk of cardiovascular disease.

Conclusion National policies relaxing disease recognition criteria have helped more workers received compensation. Criteria that quantitatively point out the hazard of prolonged working hours to cardiovascular disease prompt reductions in working hours at the corporate level. Our case study highlights potentially additional benefits of health promotion activities on the prevention of work-related cardiovascular disease.