Rapid response systems: evaluation of program context, mechanism, and outcome factors

Prevention of in-hospital cardiac arrest (IHCA) is critical to reducing morbidity and mortality as both the rates of return to pre-hospital functional status and overall survival after IHCAs are low. Early identification of patients at risk and prompt clinical intervention are vital patient safety strategies to reduce IHCA. One widespread strategy is the Rapid Response System (RRS), which incorporates early risk identification, expert consultation, and key clinical interventions to bedside nurses caring for patients in clinical deterioration. However, evidence of RRS effectiveness has been equivocal in the patient safety literature.

This study utilized a holistic Realistic Evaluation (RE) framework to identify important clinical environment (context) and system triggers (mechanisms) to refine our understanding of an RRS to improve local patient emoutcomesem and develop a foundation for building the next level of evidence within RE research. The specific aims of the study are to describe a RRS through context, mechanism, and outcome variables; explore differences in RRS outcomes between medical and surgical settings, and identify relationships between RRS context and mechanism variables for patient outcomes.

Study RRS data was collected retrospectively from a 397-bed community hospital in the Midwest; including all adult inpatient RRS events from May 2006 (2 weeks post-RRS implementation) through November 2013. RRS events were analyzed through descriptive, comparative, and proportional odds (ordinal) logistic regression analyses.

The study found the majority of adult inpatient RRS events occurred in medical settings and most were activated by staff nurses. Significant differences were noted between RRS events in medical and surgical settings; including patient status changes in the preceding 12 hours, event trigger patterns, and immediate clinical outcomes. Finally, proportional odds logistic regression revealed significant relationships between context and mechanism factors with changes in the risk of increased clinical severity immediately following at RRS event. RE was utilized to structure a preliminary study to explore the complex variables and relationships surrounding RRSs and patient outcomes. Further exploration of settings, changes in clinical status, staffing and resource access, and the ways nurses use RRSs is necessary to promote the early identification of vulnerable patients and strengthen hospital patient safety strategies.