Clinical Study of Hospital Mortality in Patients Visiting the Emergency Room at Nighttime in a City of Korea

ABSTRACT

PURPOSE: Attention has been focused recently on the impact of sleep deprivation, in-house staff, and overwork on patient outcome. The objective of this study was to determine whether any associations existed between the timing of a patient visit to an emergency setting and hospital mortality. METHOD: We analyzed retrospectively a series of consecutive visits to the emergency room of our hospital in 2003. Patients were divided according to the times of their visits to emergency room daytime (from 800 am to 600 pm) and nighttime (all others). We further divided nighttime visits into early nighttime (from 600 pm to 100 am) and late nighttime (from 100 am to 800 am) visits. The odds of death within 48 hours after visit for patients in the nighttime group were analyzed by using a multivariate logistic regression. The independent variable was visit to the emergency room during nighttime. RESULT: The patients visiting at night had a lower mortality (0.9% vs 1.6%, p=0.000), with an odd ratio for death within 48 hours, adjusted for severity of illness, of 1.265 (95% CI, 0.955-1.674). Severity of illness was the main contributor to the increased mortality rates of patients in the nighttime group. There was no significant difference in mortality rates between the early and the late nighttime subgroups. CONCLUSION: Nighttime visits to the emergency room are not associated with a higher mortality than daytime visits.