What was the aim of the review?
Adults in hospital who become unwell need to be identified quickly by clinical staff as requiring help. One way to do this is for doctors and nurses working on hospital wards to use a checklist of vital signs (e.g. blood pressure, pulse) to help them to recognise signs that patients are getting worse. These checklists are then used to refer patients to specialist teams of doctors and nurses for rapid assessment and treatment. We conducted this review to understand if using a checklist and referring to a specialist team reduces the number of deaths, unplanned intensive care unit (ICU) admissions/readmissions, hospital length of stay, and cardiac or respiratory arrest compared to hospital wards without these resources.
Key messages
We found evidence that checklists to help doctors and nurses recognise and refer patients who get worse early to specialist teams for management may result in little or no difference to the number of deaths, unplanned ICU admissions, length of hospital stay or cardiac arrests in hospital.
What did we study in the review?
This Cochrane Review presents what we know from research on the effect of hospital checklists to help doctors and nurses recognise and refer patients who are getting worse in hospital to specialist teams for help. Research has shown that patients in acute hospital wards often show early signs and symptoms, such as changes in breathing and pulse, when their condition is getting worse. It is thought that if hospital staff could identify and refer those patients who are getting worse earlier to specialist teams with appropriate knowledge and skills in acute care (active but short-term treatment), then there would be fewer deaths, unplanned ICU admissions, cardiac arrests and reduced length of stay.
What were the main results of the review?
We identified 11 studies. In total, 666,131 participants in 282 hospitals were included from seven middle- to high-income countries. The implementation of a checklist to recognise deteriorating patients and a specialist team to rapidly assess and treat presenting symptoms make little or no difference to deaths, unplanned ICU admissions, length of hospital stay, or cardiac and respiratory arrests compared to the wards or hospitals without access to the checklist and specialist team. No studies reported ICU readmission rates.
How up-to-date is this review?
The review authors searched for studies published up to May 2020.
Given the low-to-very low certainty evidence for all outcomes from non-randomised studies, we have drawn our conclusions from the randomised evidence. This evidence provides low-certainty evidence that EWS and RRS may lead to little or no difference in hospital mortality, unplanned ICU admissions, length of hospital stay or adverse events; and moderate-certainty evidence of little to no difference on composite outcome. The evidence from this review update highlights the diversity in outcome selection and poor methodological quality of most studies investigating EWS and RRS. As a result, no strong recommendations can be made regarding the effectiveness of EWS and RRS based on the evidence currently available. There is a need for development of a patient-informed core outcome set comprising clear and consistent definitions and recommendations for measurement as well as EWS and RRS interventions conforming to a standard to facilitate meaningful comparison and future meta-analyses.
Early warning systems (EWS) and rapid response systems (RRS) have been implemented internationally in acute hospitals to facilitate early recognition, referral and response to patient deterioration as a solution to address suboptimal ward-based care. EWS and RRS facilitate healthcare decision-making using checklists and provide structure to organisational practices through governance and clinical audit. However, it is unclear whether these systems improve patient outcomes. This is the first update of a previously published (2007) Cochrane Review.
To determine the effect of EWS and RRS implementation on adults who deteriorate on acute hospital wards compared to people receiving hospital care without EWS and RRS in place.
We searched CENTRAL, MEDLINE, Embase and two trial registers on 28 March 2019. We subsequently ran a MEDLINE update on 15 May 2020 that identified no further studies. We checked references of included studies, conducted citation searching, and contacted experts and critical care organisations.
We included randomised trials, non-randomised studies, controlled before-after (CBA) studies, and interrupted time series (ITS) designs measuring our outcomes of interest following implementation of EWS and RRS in acute hospital wards compared to ward settings without EWS and RRS.
Two review authors independently checked studies for inclusion, extracted data and assessed methodological quality using standard Cochrane and Effective Practice and Organisation of Care (EPOC) Group methods. Where possible, we standardised data to rates per 1000 admissions; and calculated risk differences and 95% confidence intervals (CI) using the Newcombe and Altman method. We reanalysed three CBA studies as ITS designs using segmented regression analysis with Newey-West autocorrelation adjusted standard errors with lag of order 1. We assessed the certainty of evidence using the GRADE approach.
We included four randomised trials (455,226 participants) and seven non-randomised studies (210,905 participants reported in three studies). All 11 studies implemented an intervention comprising an EWS and RRS conducted in high- or middle-income countries. Participants were admitted to 282 acute hospitals. We were unable to perform meta-analyses due to clinical and methodological heterogeneity across studies. Randomised trials were assessed as high risk of bias due to lack of blinding participants and personnel across all studies. Risk of bias for non-randomised studies was critical (three studies) due to high risk of confounding and unclear risk of bias due to no reporting of deviation from protocol or serious (four studies) but not critical due to use of statistical methods to control for some but not all baseline confounders. Where possible we presented original study data which reported the adjusted relative effect given these were appropriately adjusted for design and participant characteristics. We compared outcomes of randomised and non-randomised studies reported them separately to determine which studies contributed to the overall certainty of evidence. We reported findings from key comparisons.
Hospital mortality
Randomised trials provided low-certainty evidence that an EWS and RRS intervention may result in little or no difference in hospital mortality (4 studies, 455,226 participants; results not pooled). The evidence on hospital mortality from three non-randomised studies was of very low certainty (210,905 participants).
Composite outcome (unexpected cardiac arrests, unplanned ICU admissions and death)
One randomised study showed that an EWS and RRS intervention probably results in no difference in this composite outcome (adjusted odds ratio (aOR) 0.98, 95% CI 0.83 to 1.16; 364,094 participants; moderate-certainty evidence). One non-randomised study suggests that implementation of an EWS and RRS intervention may slightly reduce this composite outcome (aOR 0.85, 95% CI 0.72 to 0.99; 57,858 participants; low-certainty evidence).
Unplanned ICU admissions
Randomised trials provided low-certainty evidence that an EWS and RRS intervention may result in little or no difference in unplanned ICU admissions (3 studies, 452,434 participants; results not pooled). The evidence from one non-randomised study is of very low certainty (aOR 0.88, 95% CI 0.75 to 1.02; 57,858 participants).
ICU readmissions
No studies reported this outcome.
Length of hospital stay
Randomised trials provided low-certainty evidence that an EWS and RRS intervention may have little or no effect on hospital length of stay (2 studies, 21,417 participants; results not pooled).
Adverse events (unexpected cardiac or respiratory arrest)
Randomised trials provided low-certainty evidence that an EWS and RRS intervention may result in little or no difference in adverse events (3 studies, 452,434 participants; results not pooled). The evidence on adverse events from three non-randomised studies (210,905 participants) is very uncertain.