Development of a Binary End-of-Event Outcome Indicator for the NEMSIS Public Release Research Dataset

"Dead or Alive?" Assessment of the Binary End-of-Event Outcome Indicator for the NEMSIS Public Research Dataset

OBJECTIVES

The National Emergency Medical Services Information System (NEMSIS) provides a robust set of data to evaluate prehospital care. However, a major limitation is that the vast majority of the records lack a definitive outcome. This study aimed to evaluate the performance of a recently proposed method ("MLB" method) to impute missing end-of-EMS-event outcomes ("dead" or "alive") for patient care reports in the NEMSIS public research dataset.

METHODS

This study reproduced the recently published method for patient outcome imputation in the NEMSIS database and replicated the results for years 2017 through 2022 (n = 686,075). We performed statistical analyses leveraging an array of established performance metrics for binary classification from the machine learning literature. Evaluation metrics included overall accuracy, true positive rate, true negative rate, balanced accuracy, precision, F1 score, Cohen's Kappa coefficient, Matthews' coefficient, Hamming loss, the Jaccard similarity score, and the receiver operating characteristic/area under the curve.

RESULTS

Extended metrics show consistently good imputation performance from year-to-year but reveal weakness in accurately indicating the minority class: e.g., after adjustments for conflicting labels, "dead" prediction accuracy is 77.7% for 2018 and 61.8% over the six-year NEMSIS sub-sample, even though overall accuracy is 98.8%. Slight over-fitting is also present.

CONCLUSIONS

This study found that the recently published MLB method produced reasonably good "dead" or "alive" indicators. We recommend reporting of True Positive Rate ("dead" prediction accuracy) and True Negative Rate ("alive" prediction accuracy) when applying the imputation method for analyses of NEMSIS data. More attention by EMS clinicians to complete documentation of target NEMSIS elements can further improve the method's performance.

Spanish vs USA cohort comparison of prehospital trauma scores to predict short-term mortality

BACKGROUND

This study aimed to evaluate three prehospital early warning scores (EWSs): RTS, MGAP and MREMS, to predict short-term mortality in acute life-threatening trauma and injury/illness by comparing United States (US) and Spanish cohorts.

METHODS

A total of 8,854 patients, 8,598/256 survivors/nonsurvivors, comprised the unified cohort. Datasets were randomly divided into training and test sets. Training sets were used to analyse the discriminative power of the scores in terms of the area under the curve (AUC), and the score performance was assessed in the test set in terms of sensitivity (SE), specificity (SP), accuracy (ACC) and balanced accuracy (BAC).

RESULTS

The three scores showed great discriminative power with AUCs>0.90, and no significant differences between cohorts were found. In the test set, RTS/MREMS/MGAP showed SE/SP/ACC/BAC values of 86.0/89.9/89.6/87.1%, 91.0/86.9/87.5/88.5%, and 87.7/82.9/83.4/85.2%, respectively.

CONCLUSIONS

All EWSs showed excellent ability to predict the risk of short-term mortality, independent of the country.

Documented Use of Emergency Medical Dispatch Protocols is Associated with Improved Survival in Out of Hospital Cardiac Arrest

OBJECTIVE

There are over 300,000 out-of-hospital cardiac arrests (OHCA) annually in the United States (US) and despite many scientific advances in the field, the survival rate remains low. We seek to determine if return of spontaneous circulation (ROSC) is higher when use of emergency medical dispatch (EMD) protocols is documented for OHCA calls compared to when no EMD protocol use is documented. We also seek identify care-related processes that differ in calls that use EMD protocols.

METHODS

This is a retrospective cohort study of U.S. adults with OHCA prior to emergency medical services (EMS) arrival using 2019 National EMS Information System data. The primary exposure was EMD usage during EMS call. The primary outcome was prehospital ROSC, and secondary outcomes included automated external defibrillator (AED) use before EMS arrival, bystander CPR, and end-of-event EMS survival (survival to the end of the EMS care at transport destination). Multivariable logistic regression adjusted for age, sex, race/ethnicity, primary insurance, rurality, initial rhythm, arrest etiology, and witnessed arrest.

RESULTS

Of the 96,269 OHCA cases included, EMD use was documented in 73%. Overall, 26% of subjects achieved ROSC in EMS care. EMD subjects were more likely to achieve ROSC (27.2% vs. 23.5%, uOR 1.22, 95%CI 1.18 - 1.26) even after adjusting for subject and arrest characteristics (aOR 1.13, 95%CI 1.08 - 1.17). EMD subjects also had higher end-of-event survival (19.1% vs. 16.4%, aOR 1.20, 95%CI 1.15 - 1.25). AED use before EMS arrival was more common in the EMD group (28.3% vs. 26.3% %diff 2.0, 95%CI 1.4 to 2.6), as was CPR before EMS arrival (63.8% vs. 55.1%, difference 8.6%, 95%CI 7.9 to 9.3%).

CONCLUSIONS

In this retrospective analysis, the rate of ROSC was higher in adult OHCA patients when EMD protocol use was reported compared to when it was not reported. The group with documented EMD use also experienced higher rates of bystander AED use, bystander CPR, and end-of-event survival.

Prehospital Management of Pediatric Behavioral Health Emergencies: A Scoping Review

Pediatric behavioral health emergencies (BHE) are increasing in prevalence, yet there are no evidence-based guidelines or protocols for prehospital management. The primary objective of this scoping review is to identify prehospital-specific pediatric BHE research and publicly available emergency medical services (EMS) protocols for pediatric BHE. Secondary objectives include identifying the next priorities for research and EMS protocol considerations for children with neurodevelopmental conditions. This is a scoping review comprised of a research literature search for publications from 2012-2022 and an internet search for publicly available EMS protocols from the United States. Included publications contain data on the epidemiology of pediatric BHE or describe prehospital management of pediatric BHE. EMS protocols were included if they had advisements specific to pediatric BHE. A total of 50 research publications and EMS protocols from 43 states were screened. Seven publications and four protocols were included in this study. Research studies indicated an increase in pediatric BHE over the last decade, but few papers discuss current prehospital management (n=4). Two EMS protocols were specific to pediatric BHE or pediatric agitation, and the other two EMS protocols focused on adult populations with integrated pediatric recommendations. All four EMS protocols encouraged nonpharmaceutical interventions prior to the use of pharmacologic restraints. Although there is a substantial rise in pediatric BHE, there is sparse research data and clinical EMS protocols to support best practices for prehospital pediatric BHE management. This scoping review identifies important future research aims to inform best practices for the prehospital management of pediatric BHE.

Differences in Out-of-Hospital Cardiac Arrest Management and Outcomes across Urban, Suburban, and Rural Settings

BACKGROUND

Rural prehospital care settings are underrepresented in the out-of-hospital cardiac arrest (OHCA) literature. This study aimed to describe treatment patterns and the odds of a favorable patient outcome (e.g., return of spontaneous circulation (ROSC) or being presumptively alive at the end of the incident) among rural OHCA patients in the U.S.

METHODS

Using the 2018 National Emergency Medical Services Informational System (NEMSIS) dataset, we analyzed OHCA incidents where an emergency medical services (EMS) unit provided cardiopulmonary resuscitation (CPR) and either terminated the resuscitation or completed transport. We excluded traumatic injuries, pediatric patients, and incidents with response time >60 minutes. The primary outcome was ROSC at any time during the EMS incident. The secondary outcome was a binary end-of-event indicator previously described for use in NEMSIS to estimate longer-term outcomes. Multivariable logistic regression was performed for each outcome measure comparing rural, suburban, and urban settings while controlling for key factors.

RESULTS

A total of 64,489 OHCA incidents were included, with 5,601 (8.9%) in rural settings. Among the full sample of OHCA incidents, ROSC was achieved in 20,578 (33.6%) cases, including 29.2% in rural settings and 34.1% in urban or suburban settings (p < 0.001). Advanced life support units responded to 95.3% of all calls, and a greater proportion of rural OHCA incidents were managed by basic life support units (7.4% vs. 4.2%, p < 0.001). Rural OHCA incidents had longer response times (7.5 vs. 5.9 minutes, p < 0.001), and rural patients were less likely to receive epinephrine (69.3% vs. 73.3%, p < 0.001). Further, EMS clinicians in rural areas were more likely to use mechanical CPR (29.5% vs. 27.6%, p < 0.01) and were less likely to perform advanced airway management (48.5% vs. 54.2%, p < 0.001). Rural patients had lower odds of achieving ROSC than urban patients after controlling for other factors (OR 0.81, 95% CI: 0.75-0.87). Rural patients also had lower odds of having a positive end-of-event outcome (i.e., presumptively alive) after controlling for other factors (OR 0.86, 95% CI: 0.79-0.93).

CONCLUSION

In this national sample of EMS-treated OHCAs, rural patients had lower odds of a favorable outcome (e.g., ROSC or presumptively alive) compared to those in urban settings.

Prehospital care for traumatic cardiac arrest in the US: A cross-sectional analysis and call for a national guideline

AIM

We describe emergency medical services (EMS) protocols and prehospital practice patterns related to traumatic cardiac arrest (TCA) management in the U.S.

METHODS

We examined EMS management of TCA by 1) assessing variability in recommended treatments in state EMS protocols for TCA and 2) analyzing EMS care using a nationwide sample of EMS activations. We included EMS activations involving TCA in adult (≥18 years) patients where resuscitation was attempted by EMS. Descriptive statistics for recommended and actual treatments were calculated and compared between blunt and penetrating trauma using χ² and independent 2-group Mann-Whitney U tests.

RESULTS

There were 35 state EMS protocols publicly available for review, of which 16 (45.7%) had a specific TCA protocol and 17 (48.5%) had a specific termination of resuscitation protocol for TCA. Recommended treatments varied. We then analyzed 9,565 EMS activations involving TCA (79.1% blunt, 20.9% penetrating). Most activations (93%) were managed by advanced life support. Return of spontaneous circulation was achieved in 25.5% of activations, and resuscitation was terminated by EMS in 26.4% of activations. Median prehospital scene time was 16.4 minutes; scene time was shorter for penetrating mechanisms than blunt (12.0 vs 17.0 min, p < 0.001). Endotracheal intubation was performed in 32.0% of activations, vascular access obtained in 66.6%, crystalloid fluids administered in 28.8%, and adrenaline administered in 60.1%.

CONCLUSION

Actual and recommended approaches to EMS treatment of TCA vary nationally. These variations in protocols and treatments highlight the need for a standardized approach to prehospital management of TCA in the U.S.