Call characteristics and factors associated with outcomes of in-hospital cardiac arrest response teams: a 10-year retrospective cohort study.

Objective: To analyze hospital code blue team (HCBT) call data over a 10-year period and to explore call characteristics and factors associated with clinical outcomes following in-hospital cardiac arrest (IHCA). Design: A single-center retrospective cohort study conducted over 10 years. Setting: A tertiary hospital in China providing comprehensive inpatient care. Participants: A total of 454 patients who experienced IHCA and triggered HCBT activation between January 2016 and December 2025 were included. The mean age was 65.76 years (SD 14.71), and 55.95% were male. Data analysis: Descriptive statistics were used to summarize baseline characteristics and call features. Independent-samples Primary outcome measures: The primary outcome was clinical outcome following HCBT activation. Outcomes were classified as favourable (remained on the ward, survival requiring transfer to the intensive care unit, emergency department, or operating room for continued treatment) or unfavourable (in-hospital death or discharge against medical advice). All data were obtained from the institutional HCBT database. Results: A total of 454 HCBT activations were recorded during the study period. The most common underlying diagnoses were circulatory, respiratory, and digestive system diseases. Following resuscitation, the majority of patients were transferred to the intensive care unit (ICU) (50.22%), while a smaller proportion remained in the ward (10.13%). The proportion of discharge against medical advice was 27.53%, and the direct in-hospital mortality rate was 8.59%. The five-minute arrival rate of the HCBT was 98.68%. Advanced age was independently associated with unfavourable clinical outcome. Events occurring during daytime hours were associated with improved survival. In addition, cases first recognized by healthcare professionals demonstrated significantly better outcomes compared with those identified by caregivers. Conclusion: IHCA most frequently occurred in patients with cardiovascular and respiratory diseases. Although the team achieved a high five-minute arrival rate, overall survival remained suboptimal, particularly among older patients. Daytime events and early recognition by healthcare professionals were associated with better survival outcomes, highlighting the importance of rapid response and system-level improvements to improve in-hospital resuscitation performance.