Admission time and outcomes of patients in a medical intensive care unit

Studies have shown that weekend or night admissions to intensive care units (ICUs) are associated with increased mortality in critically ill patients. Our study aimed to evaluate the effects of admission time and day on patient outcomes in a medical ICU equipped with patient management guide-lines, and staffed by intensivists on call for 24 hours, who led the morning rounds on all days of the week but did not stay in-house overnight. The study enrolled 611 consecutive patients admitted to a 26-bed medical ICU in a university hospital during a 7-month period. We divided them into two groups, which we labeled as "office hours" (08:00-18:00 on weekdays) and "non-office hours" (18:00-08:00 on weekdays, and all times on weekends) according to their ICU admission times. The clinical outcomes were compared between the groups. The effects of admission on weekends, at night, and various days of the week on hospital mortality were also evaluated. Our results showed that there were no significant differences in ICU and hospital mortalities between patients admitted during office hours and those admitted during non-office hours (27.2% vs. 27.4%, p = 1.000; 38.9% vs. 37.6%, p = 0.798). The ICU length of stay, ICU-free time within 21 days, and length of stay in the hospital were also comparable in both groups. Among the 392 patients requiring mechanical ventilation, the ventilator outcomes were not significantly different between those in the office-hour group and the non-office-hour group. Multivariate logistic regression analyses showed that the adjusted odds of hospital mortality were not significantly higher for patients admitted to our ICU on weekends, at night, or on any days of the week. In conclusion, our results showed that non-office-hour admissions to our medical ICU were not associated with poorer ICU, hospital, and ventilator outcomes, compared with office-hour admissions. Neither were time of day and day of the week admissions to our ICU associated with significant differences in hospital mortality.