Fatal pulmonary embolism in hospitalized patients: evidence for a winter peak

This study was intended to determine whether there are circa-annual variations in the incidence of fatal pulmonary embolism for hospitalized patients. Patients (152), admitted into both the medical and surgical departments of St. Anna Hospital of Ferrara, Italy, during an 8-year period (1983-1990) and who died in hospital as a result of pulmonary embolism, were considered. The day and month of death were registered, and analysed by inferential statistics (single cosinor). A circa-annual variation, with a statistically significant peak in late January (P = 0.002), was found for the total sample. After stratification by sex, this winter peak was confirmed only for women (P = 0.006).