Workday-rescheduling effects on ST-segment elevation myocardial infarction: a registry study analysis

This study assessed whether China's workday-rescheduling policy is associated with short-term and long-term outcomes in patients with ST-segment elevation myocardial infarction (STEMI), particularly in occupational groups more likely to be affected by rescheduling.

A prospective cohort study was conducted using data from the China Acute Myocardial Infarction registry between January 2013 and September 2014. A total of 15 854 STEMI patients were included. Since individual adherence to workday rescheduling is not directly measured in the registry, occupational category was used as a proxy to define groups more likely versus less likely to be affected by the workday-rescheduling policy. The primary outcome was in-hospital all-cause mortality. Secondary outcomes included in-hospital major adverse cardiovascular and cerebrovascular events (MACCE) and 2 year all-cause mortality. Multivariable logistic and Cox regression models were used for analysis.

Using occupational category as a proxy for the likelihood of exposure to workday rescheduling, we stratified patients into a rescheduling-likely group (n=3141) and a rescheduling-unlikely group (n=12 713). Among patients in the rescheduling-likely occupational group, in-hospital mortality was significantly higher during abnormal workdays than conventional weekdays (7.8% vs 3.44%; adjusted OR=3.01; 95% CI 1.40 to 6.45). Two-year mortality was also higher (adjusted HR=1.99; 95% CI 1.20 to 3.30). Among 12 713 patients in the rescheduling-unlikely occupational group, no significant mortality differences were observed across temporal groups. Within the rescheduling-likely group, baseline characteristics and care quality indicators were generally comparable across the four temporal groups.

Workday-rescheduling-induced abnormal work cycles are associated with higher in-hospital and 2 year adverse events in affected ST-segment elevation myocardial infarction patients. These findings should be interpreted as heterogeneity in the association between abnormal workdays and mortality by occupational likelihood of rescheduling exposure rather than as a direct individual-level causal effect of rescheduling.