Circadian aspects of mortality in hospitalized patients: A retrospective observation from a large cohort.

A total of 3300 cases were included in the present study (male, 63.4% and median age 73 years), including 1540 (46.7%) ICU patients. Incidence of overall hospitalized death exhibited a circadian pattern, presenting peaks from 07:00 to 12:00 and 15:00 to 20:00 P.M., with 21.5% and 13.1% increase above the average at those peak points, respectively. Similarly, the incidence of sudden cardiac death (SCD) showed peaks between 06:00-12:00 and 15:00-20:00, with a 34.7% and 28.0% increase above the average at peak time, respectively. The distribution of death incidence revealed no statistical difference between SCD and non-SCD (p = 0.525).