Association between time of day for rapid response team activation and mortality

To evaluate the frequency of rapid response team (RRT) calls by time of day and their association with in-hospital mortality.

This was a retrospective cohort study of all RRT calls at a tertiary teaching hospital in Porto Alegre, Brazil. Patients were categorized according to the time of initial RRT activation. Activations were classified as daytime (7:00-18:59) or nighttime (19:00-6:59). The primary outcome was in-hospital mortality rate. The secondary outcome was ICU admission within 48 h of RRT assessment.

During the study period, 4522 patients were included in the final analysis. Cardiovascular and respiratory changes were more common causes of nighttime activation, whereas neurological and laboratory changes were more common during the daytime. The in-hospital mortality rate was 23.9% (1081/4522). Nighttime RRT calls were not associated with worse outcomes than daytime calls. However, a decrease in the number of calls was observed during nursing handover periods (7:00, 13:00 and 19:00). Two time periods were associated with increased adjusted odds for mortality: 12:00-13:00 (adjusted OR 2.277; 95% CI 1.392-3.725) and 19:00-20:00 (adjusted OR 1.873; CI 1.873; 95% 1.099-3.190).

We found that nighttime RRT calls were not associated with worse outcomes than daytime RRT calls. However, a decrease in the number of calls and higher mortality was observed during nursing handover periods.