Validation of the VitalPAC™ Early Warning Score (ViEWS) in acutely ill medical patients attending a resource-poor hospital in sub-Saharan Africa

Background

The VitalPAC™ Early Warning Score (ViEWS) has an area under the receiver operator characteristic curve (AUROC) for death of acute unselected medical patients within 24 h of 88% and the UK National Early Warning Scores is based on it. The score's discrimination has been validated on patients in the developed world, but nothing is known of its performance in resource-poor hospitals.

Methods

ViEWS was validated in 844 acutely ill medical patients admitted to Kitovu Hospital, Masaka, Uganda.

Results

The AUROC for death within 24 h of admission was 88.6% (95% CI 82.5–94.7%). The inability to walk without help was found to be an additional independent predictor of in-hospital mortality, and ViEWS modified to include it had an AUROC for death within 24 h of 91.9% (95% CI 86.5–97.2%).

Conclusion

The discrimination of ViEWS in a resource poor sub-Saharan Africa hospital is the same as in the developed world. Inability to walk without help was found to be an additional independent predictor of mortality.     

Changes and their prognostic implications in the abbreviated Vitalpac™ early warning score (ViEWS) after admission to hospital of 18,853 acutely ill medical patients

Background

The best performing early warning score is Vitalpac™ Early Warning Score (ViEWS). However, it is not known how often, to what extent and over what time frame any early warning scores change, and what the implications of these changes are.

Setting

Thunder Bay Regional Health Sciences Center, Ontario, Canada.

Methods

The changes in the first three complete sets of the six variables required to retrospectively calculate the abbreviated version of ViEWS (that did not include mental status) after admission to hospital of 18,853 acutely ill medical patients, and their relationship to subsequent in-hospital mortality were examined.

Results

In the 10.4 SD 20.1 (median 5.0) hours between admission and the second recording the score changed in only 5.9% of patients and these changes were of no prognostic value. By the time of the third recording 34.9 SD 21.7 (median 30.0) hours after admission a change in score was clearly associated with a corresponding change in in-hospital mortality (e.g. for patients with an initial score of 5 an increase between the first and third recording of ≥4 points was associated with an increased mortality (OR 6.5 95% CI 2.3–15.9, p < 0.00001), whereas a reduction of ≤−4 points was associated with a reduced mortality (OR 0.4 95% CI 0.2–0.9, p 0.03)).

Conclusion

After a median interval of 30 h both the initial abbreviated ViEWS recording and subsequent changes in it both predict clinical outcome. It remains to be determined what interventions during this time frame will improve patient outcomes.     

Decision-tree early warning score (DTEWS) validates the design of the National Early Warning Score (NEWS)

Aim of study

: To compare the performance of a human-generated, trial and error-optimised early warning score (EWS), i.e., National Early Warning Score (NEWS), with one generated entirely algorithmically using Decision Tree (DT) analysis.

Materials and methods

We used DT analysis to construct a decision-tree EWS (DTEWS) from a database of 198,755 vital signs observation sets collected from 35,585 consecutive, completed acute medical admissions. We evaluated the ability of DTEWS to discriminate patients at risk of cardiac arrest, unanticipated intensive care unit admission or death, each within 24 h of a given vital signs observation. We compared the performance of DTEWS and NEWS using the area under the receiver-operating characteristic (AUROC) curve.

Results

The structures of DTEWS and NEWS were very similar. The AUROC (95% CI) for DTEWS for cardiac arrest, unanticipated ICU admission, death, and any of the outcomes, all within 24 h, were 0.708 (0.669–0.747), 0.862 (0.852–0.872), 0.899 (0.892–0.907), and 0.877 (0.870–0.883), respectively. Values for NEWS were 0.722 (0.685–0.759) [cardiac arrest], 0.857 (0.847–0.868) [unanticipated ICU admission}, 0.894 (0.887–0.902) [death], and 0.873 (0.866–0.879) [any outcome].

Conclusions

The decision-tree technique independently validates the composition and weightings of NEWS. The DT approach quickly provided an almost identical EWS to NEWS, although one that admittedly would benefit from fine-tuning using clinical knowledge. We believe that DT analysis could be used to quickly develop candidate models for disease-specific EWSs, which may be required in future.     

The ability of the National Early Warning Score (NEWS) to discriminate patients at risk of early cardiac arrest,unanticipated intensive care unit admission,and death

Introduction

Early warning scores (EWS) are recommended as part of the early recognition and response to patient deterioration. The Royal College of Physicians recommends the use of a National Early Warning Score (NEWS) for the routine clinical assessment of all adult patients.

Methods

We tested the ability of NEWS to discriminate patients at risk of cardiac arrest, unanticipated intensive care unit (ICU) admission or death within 24 h of a NEWS value and compared its performance to that of 33 other EWSs currently in use, using the area under the receiver-operating characteristic (AUROC) curve and a large vital signs database (n = 198,755 observation sets) collected from 35,585 consecutive, completed acute medical admissions.

Results

The AUROCs (95% CI) for NEWS for cardiac arrest, unanticipated ICU admission, death, and any of the outcomes, all within 24 h, were 0.722 (0.685–0.759), 0.857 (0.847–0.868), 0.894 (0.887–0.902), and 0.873 (0.866–0.879), respectively. Similarly, the ranges of AUROCs (95% CI) for the other 33 EWSs were 0.611 (0.568–0.654) to 0.710 (0.675–0.745) (cardiac arrest); 0.570 (0.553–0.568) to 0.827 (0.814–0.840) (unanticipated ICU admission); 0.813 (0.802–0.824) to 0.858 (0.849–0.867) (death); and 0.736 (0.727–0.745) to 0.834 (0.826–0.842) (any outcome).

Conclusions

NEWS has a greater ability to discriminate patients at risk of the combined outcome of cardiac arrest, unanticipated ICU admission or death within 24 h of a NEWS value than 33 other EWSs.     

Measuring adherence among nurses one year after training in applying the Modified Early Warning Score and Situation-Background-Assessment-Recommendation instruments

Background

Patients with a cardiac arrest or unplanned intensive care admission show gradual decline in clinical condition preceding the event. This can be objectified by measuring the vital parameters and subsequently determining the Modified Early Warning Score (MEWS). Contact with the physician by nurses may be structured using the Situation-Background-Assessment-Recommendation (SBAR) communication instrument. The aim of our study was to evaluate whether nurses trained in the use of MEWS and SBAR tools were more likely to recognize a deteriorating patient.

Design and setting

This prospective quasi-experimental trial in the Academic Medical Center in Amsterdam, the Netherlands included three medical and three surgical wards.

Interventions

A group of 47 trained and 48 non-trained nurses were presented with a case of a deteriorating patient, and subsequent assessment and actions regarding the patient case were measured.

Results

Of the trained nurses, 77% versus 58% of the non-trained group assessed the patient immediately. On subsequent assessment of the patient, respiratory rate was measured twice as frequently (53% trained versus 25% non-trained, p = 0.025). No differences were found in the measurement of other vital parameters. The MEWS was determined by 11% of trained nurses. Subsequent notification of the physician was performed by 67% of the trained versus 43% of the non-trained nurses. The SBAR communication tool was used by only one nurse.

Conclusions

Trained nurses are able to identify a deteriorating patient and react more appropriately. However, despite rigorously implementing MEWS/SBAR methodology, these tools were rarely used.     

Factors affecting response to National Early Warning Score (NEWS)

IntroductionThe NEWS is a physiological score, which prescribes an appropriate response for the deteriorating patient in need of urgent medical care. However, it has been suggested that compliance with early warning scoring systems for identifying patient deterioration may vary out of hours. We aimed to (1) assess the scoring accuracy and the adequacy of the prescribed clinical responses to NEWS and (2) assess whether responses were affected by time of day, day of week and score severity.MethodsWe performed a prospective observational study of 370 adult patients admitted to an acute medical ward in a London District General Hospital. Patient characteristics, NEW score, time of day, day of week and clinical response data were collected for the first 24 h of admission. Patients with less than a 12 h hospital stay were excluded. We analysed data with univariate and multivariate logistic regression.ResultsIn 70 patients (18.9%) the NEW score was calculated incorrectly. There was a worsening of the clinical response with increasing NEW score. An appropriate clinical response to the NEWS was observed in 274 patients (74.1%). Patients admitted on the weekend were more likely to receive an inadequate response, compared to patients admitted during the week (p < 0.0001). After adjusting for confounders, increasing NEWS score remained significantly associated with an inadequate clinical response. Furthermore, our results demonstrate a small increase in inadequate NEWS responses at night, however this was not clinically or statistically significant.ConclusionThe high rate of incorrectly calculated NEW scores has implications for the prescribed actions. Clinical response to NEWS score triggers is significantly worse at weekends, highlighting an important patient safety concern.     

比较早期预警评分和改良早期预警评分在急诊的应用价值

目的：比较早期预警评分（EWS）和改良早期预警评分（MEWS）预测急诊住院患者死亡风险的能力。方法：随机抽取409名四川大学华西医院急诊住院患者,采用EWS和MEWS对患者进行评分,使用ROC曲线比较两者预测急诊住院患者死亡风险的能力。结果：EWS预测患者住院的曲线面积为0.849±0.132,其最佳截断值为4分;MEWS预测急诊患者住院的曲线下面积为0.876±0.124,其最佳截断值为5分。结论：MEWS较EWS对于预测急诊住院患者死亡风险有较高的效能,还可以进一步改进提高其预测能力。     

Trajectories of the averaged abbreviated Vitalpac™ early warning score (AbEWS) and clinical course of 44,531 consecutive admissions hospitalized for acute medical illness

Background

It is not known how often, to what extent and over what time frame any early warning scores change, and what the implications of these changes are.

Setting

Thunder Bay Regional Health Sciences Center, Ontario, Canada.

Methods

The averaged vital signs measured over different time periods of 44,531 consecutive acutely ill medical admissions were determined and then combined to calculate the averaged abbreviated version of the Vitalpac™ early warning score (AbEWS) during each time period examined.

Results

18% of all in-hospital deaths within 30 days are in patients with a low AbEWS on admission. Those admitted with a low AbEWS are more likely to increase their score and those admitted with a high score are more likely to lower it. Paradoxically, patients who have an averaged score over the first 6 h in hospital that is lower than on admission have increased in-hospital mortality. Thereafter patients with an increase in the averaged score have almost twice the mortality of those with a decreased score. 4.7% of patients have a low averaged score on the day they die.

Conclusion

AbEWS, without clinical judgment, cannot be used to detect those patients who do not need to be admitted to hospital or are suitable for discharge. A period of observation of at least 12 h is required before the trajectory of AbEWS is of prognostic value, and any “improvement” that occurs before this time may be illusory.     

改良早期预警评分评估急诊潜在危重症患者病情能力的研究

目的了解改良早期预警评分对急诊潜在危重症患者病情评估的可行性和适用性。方法对门急诊2014年2月至3月接诊的670例患者进行改良早期预警评分,追踪所有患者的去向。统计分析改良早期预警与患者去向的相关性。比较门诊治疗、入住普通病房、收入ICU患者的改良早期预警评分,改良早期预警评分对患者病情评估分辨度的ROC曲线。结果以患者是否收住ICU为预测指标时,改良早期预警评分的最佳截断值为4分,灵敏度70.56%,特异度73.36%,阳性预测值52.45%,阴性预测值85.68%,ROC曲线下面积AZ=0.77(95%CI:0.734,0.814)。结论改良早期预警评分可用于判断急诊患者病情严重程度,对其是否收住ICU具有中等程度预测价值。改良早期预警评分操作简单快捷,费用低廉,可实现对患者病情快速动态评估,适用于急诊患者。     

Standardized measurement of the Modified Early Warning Score results in enhanced implementation of a Rapid Response System: A quasi-experimental study

Purpose

To study the effect of protocolized measurement (three times daily) of the Modified Early Warning Score (MEWS) versus measurement on indication on the degree of implementation of the Rapid Response System (RRS).

Methods

A quasi-experimental study was conducted in a University Hospital in Amsterdam between September and November 2011. Patients who were admitted for at least one overnight stay were included. Wards were randomized to measure the MEWS three times daily (“protocolized”) versus measuring the MEWS “when clinically indicated” in the control group. At the end of each month, for an entire seven-day week, all vital signs recorded for patients were registered. The outcomes were categorized into process measures including the degree of implementation and compliance to set monitoring standards and secondly, outcomes such as the degree of delay in physician notification and Rapid Response Team (RRT) activation in patients with raised MEWS (MEWS ≥ 3).

Results

MEWS calculations from vital signs occurred in 70% (2513/3585) on the protocolized wards versus 2% (65/3013) in the control group. Compliance with the protocolized regime was presents in 68% (819/1205), compliance in the control group was present in 4% (47/1232) of the measurements. There were 90 calls to primary physicians on the protocolized and 9 calls on the control wards. Additionally on protocolized wards, there were twice as much RRT calls per admission.

Conclusions

Vital signs and MEWS determination three times daily, results in better detection of physiological abnormalities and more reliable activations of the RRT.     

Clinical emergencies and outcomes in patients admitted to a surgical versus medical service

Background

The merit of rapid response systems (RRSs) remains controversial. A tailored approach to specific groups may increase the efficacy of these teams. The purpose of this study was to compare differences in triggers for RRS activation, interventions, and outcomes in patients on medical and surgical services.

Methods

A retrospective review RRS events was performed. The incidence of out of ICU cardiac arrests and hospital mortality were compared 2 years prior to and following RRS implementation. Call trigger, interventions, and disposition between medical and surgical patients were compared over a 15 month period.

Results

Out of ICU cardiac arrest was significantly more prevalent in the medical group both before and after implementation of RRS. The out of ICU cardiac arrest rate decreased 32% in the surgical group (p = 0.05) but hospital mortality did not change. Out of ICU cardiac arrest decreased 40% in the medical group (p < 0.001) and hospital mortality decreased 25% (p < 0.001) following RRS implementation. There were 1082 RRS activations, 286 surgical and 796 medical. Surgical patients were more likely to have received sedation within 24 h of evaluation (14% vs. 4%, p < 0.001). The majority of patients in both cohorts were discharged alive.

Conclusion

Implementation of a RRS had greater impact on reduction of out of ICU cardiac arrest and mortality in medical inpatients. Triggers for activation and interventions were similar between groups; however, surgical patients demonstrated substantial risk for decompensation within the first 24 h following operation. More research is needed to evaluate the disproportionate benefit observed between cohorts.     

In‐hospital mortality and morbidity of elderly medical patients can be predicted at admission by the Modified Early Warning Score: a prospective study

Objective: Although early warning scores were originally derived as bedside tools for alerting the medical staff, they may serve as decision rules for the admission of medical patients. We conducted this study to investigate the ability of the Modified Early Warning Score (MEWS) to identify a subset of patients at risk of deterioration, who might benefit from an increased level of attention. Design: Prospective, single centre, cohort study. Setting: A 64‐bedded medical ward in a public, non‐teaching Hospital in Italy. Patients: All patients consecutively admitted from 15th November 2005 to 9th June 2006. Interventions: On admission, the attending physician measured five physiological parameters (systolic blood pressure, pulse rate, respiratory rate, body temperature and level of consciousness) and calculated the MEWS. The main outcome measures were in‐hospital mortality and a composite of mortality and transfer to a higher level of care. A secondary end‐point was the length of stay for discharged patients. Measurements and results: In all, 1107 patients were admitted; 621 (56.1%) were women and 486 were men. Patients of female gender were also older (mean age 80.6 years) than men (mean age 77.1; p < 0.05). Of 1107, 995 patients (89.9%) were older than 64 years. A total of 966 patients were discharged, 102 deceased and 39 were transferred. In comparison with the lowest score, the risk of death was incremental among all the MEWS categories, as well as the risk of the combined outcome of death and transfer, and highly significant (risk of death, χ² for trend 136.307; risk of death or transfer, χ² for trend 105.762; p < 0.00001 for both). Patients with MEWS ≤ 4 were discharged after a mean stay of 8.3 days, and alive patients with MEWS of five or more were discharged after a mean stay of 9.4 days (p = ns). A patient with a MEWS of zero at admission has a very low probability to die or to be transferred because of clinical instability (OR 0.14, 95% CI: 0.08–0.24). Conclusions: We have confirmed that the MEWS, even when calculated once on admission, is a simple but highly useful tool to predict a worse in‐hospital outcome.     

校正改良式早期预警系统在心胸专科急诊分诊中的应用

目的将改良式早期预警(modified early warning score,MEWS)与胸科专科预检标准相结合,构建适用于心胸专科急诊分诊的校正MEWS系统,探讨其对于心胸专科急诊预检分诊工作的影响。方法便利抽样法选取上海交通大学附属胸科医院2015年9-12月急诊就诊患者8994例为对照组,2016年1-3月急诊就诊患者9138例为观察组。对照组患者按常规的急诊分诊流程处理,观察组患者实施校正MEWS系统的评分结果进行预检及分区分级处置,比较两组患者急诊分诊时间及分诊正确率、高危胸痛患者识别率、应急处理率,医生、护士及患者满意率。结果两组患者的分诊时间、分诊正确率、有效识别高危胸痛患者、应急处理率、患者满意率经比较,观察组患者均优于对照组,差异均有统计学意义(均P0.05)。结论校正MEWS评分系统便于急诊护士快速准确地分诊,同时可有效识别胸痛高危患者,提高心胸专科急诊预检分诊工作的可操作性及准确率,有助于急诊患者在最短时间内得到规范、科学、适当、合理、及时的救治。