Benefits and Harms

• Based on systematic reviews and primary studies included in this review, rapid response systems may have a large beneficial effect on the outcomes of hospital mortality and the incidence of in-hospital cardiorespiratory arrest (defined as arrests outside of the intensive care unit (ICU) and/or emergency department) but the strength of the evidence for that benefit is low for adults due to methodological weaknesses in the studies. For pediatrics, rapid response systems may have a large impact on hospital mortality, but like adults, the strength of the evidence is low due to methodological weaknesses. The effect on in-hospital cardiorespiratory arrest is unclear in pediatric populations (insufficient strength of evidence)
• The impact of rapid response systems on unanticipated intensive care unit (ICU) admission is unclear (insufficient strength of evidence for adult and pediatric populations).
• Modifications to the afferent and/or efferent limb were associated with a reduction in mortality and the incidence of cardiorespiratory arrest for adults (low strength of evidence) but the evidence was insufficient in pediatric populations in the primary studies reporting on these outcomes.
• Serious adverse events (e.g., intubation and need for mechanical ventilation, arrest soon after ICU arrival, ICU mortality, and severity scores on arrival to a higher level of care) were infrequently reported (insufficient strength of evidence for both populations).
• One included systematic review examined unintended consequences of rapid response system staffing models requiring ICU staff to respond to activations, but the evidence from that review was insufficient to support a conclusion about the risk for ICU patients while ICU staff were away.
• The quality of the rapid response system literature is limited by significant heterogeneity and risk of bias, and studies often draw conclusions with limited or no statistical analysis.

Future Research Needs

• Modifications to both the afferent limb and efferent limbs have improved the outcomes of incidence of cardiorespiratory arrest and hospital mortality. Future research should seek to develop sensitive and specific strategies for earlier recognition of clinical deterioration since many studies have shown that failure to rescue is a persistent problem despite the wide implementation of rapid response systems. Additionally, future research needs to examine the unintended consequences as well as the benefits of efferent limb staffing models because of concerning data about how current rapid response efferent limb staffing models that use dual responsibilities with critically ill ICU patients may put those ICU patients at risk.
• Family activation of rapid response systems is a promising development, but future research should compare different methods of engaging family members in activation in addition to comparing clinician-initiated activation to family-initiated activations. Family-initiated rapid response activations have very different drivers behind the activation and the need for transfer to a higher level of care after family-initiated activation is much less common than with clinician-initiated activation. Further studies are needed to improve understanding of the differences between family-initiated and clinician-initiated activations so that rapid responses systems can be appropriately tailored to address the concerns identified by families or clinicians.

Objectives. Rapid response systems address unexpected and unrecognized clinical deterioration on general hospital wards and aim to prevent cardiorespiratory arrests. These systems have an afferent limb (recognition and activation) and an efferent limb (response). Our main objectives were to determine the effectiveness of rapid response systems on patient safety and clinical outcomes and how rapid response systems can be implemented effectively.

Methods. We searched PubMed and the Cochrane library for eligible systematic reviews and primary studies published from January 2018 through June 2023, supplemented by targeted gray literature searches. We included reviews and primary studies of rapid response systems reporting the incidence of cardiorespiratory arrest, hospital mortality, transition to higher level of care, serious adverse events related to clinical deterioration, or unintended consequences.

Findings. We retrieved 867 citations, of which 23 articles were eligible for review (4 systematic reviews and 19 primary studies). Three categories of interventions were identified: implementation of a new system, modifications to the afferent limb, and modifications to the efferent limb. Based on systematic reviews and primary studies, rapid response systems may have a large impact in reducing in-hospital mortality (low strength of evidence for adult and pediatric populations) and an even greater impact in reducing the incidence of cardiorespiratory arrest on hospital general wards in adult populations (low strength of evidence), but the effect is unclear in pediatric populations (insufficient strength of evidence). Their impact on unanticipated intensive care unit (ICU) admission is unclear (insufficient strength of evidence for both populations). Modifications to the afferent and/or efferent limb were associated with a reduction in mortality and the incidence of cardiorespiratory arrest for adults (low strength of evidence) but the evidence was insufficient in pediatric populations. Serious adverse events (e.g., arrest soon after ICU arrival) were infrequently reported (insufficient strength of evidence for both adult and pediatric populations). One included systematic review of the unintended consequences of staffing models examined risks for ICU patients, but the strength of evidence was insufficient for both children and adults.

Conclusions. Overall, rapid response systems may have a large beneficial effect on the outcomes of hospital mortality and the incidence of in-hospital cardiorespiratory arrest but the strength of the evidence is low due to methodological weaknesses of the studies. Innovations in afferent and efferent limb structures show promise for increased benefit.

Winters BD, Rosen M, Sharma R, Zhang A, Bass EB. Failure To Rescue – Rapid Response Systems. Rapid Review. (Prepared by the Johns Hopkins Evidence-based Practice Center under Contract No. 75Q80120D00003). AHRQ Publication No. 23(24)-EHC019-11. Rockville, MD: Agency for Healthcare Research and Quality. March 2024. DOI: https://doi.org/10.23970/AHRQEPC_MHS4RESCUE. Posted final reports are located on the Effective Health Care Program search page.