Prehospital predicting factors using a decision tree model for patients with witnessed out-of-hospital cardiac arrest and an initial shockable rhythm
概要
Title
Prehospital predicting factors using a decision
tree model for patients with witnessed out-ofhospital cardiac arrest and an initial shockable
rhythm
Author(s)
Tateishi, Kazuya; Saito, Yuichi; Yasufuku,
Yuichi et al.
Citation
Scientific Reports. 2023, 13(1), p. 16180
Version Type VoR
URL
rights
https://hdl.handle.net/11094/92832
This article is licensed under a Creative
Commons Attribution 4.0 International License.
Note
Osaka University Knowledge Archive : OUKA
https://ir.library.osaka-u.ac.jp/
Osaka University
www.nature.com/scientificreports
OPEN
Prehospital predicting factors using
a decision tree model for patients
with witnessed out‑of‑hospital
cardiac arrest and an initial
shockable rhythm
Kazuya Tateishi 1,8*, Yuichi Saito 1,8, Yuichi Yasufuku 2,8, Atsushi Nakagomi 1,8,
Hideki Kitahara 1, Yoshio Kobayashi 1, Yoshio Tahara 3, Naohiro Yonemoto 4, Takanori Ikeda 5,
Naoki Sato 6 & Hiroyuki Okura 7
The effect of prehospital factors on favorable neurological outcomes remains unclear in patients with
witnessed out-of-hospital cardiac arrest (OHCA) and a shockable rhythm. We developed a decision
tree model for these patients by using prehospital factors. Using a nationwide OHCA registry database
between 2005 and 2020, we retrospectively analyzed a cohort of 1,930,273 patients, of whom 86,495
with witnessed OHCA and an initial shockable rhythm were included. The primary endpoint was
defined as favorable neurological survival (cerebral performance category score of 1 or 2 at 1 month). A
decision tree model was developed from randomly selected 77,845 patients (development cohort) and
validated in 8650 patients (validation cohort). In the development cohort, the presence of prehospital
return of spontaneous circulation was the best predictor of favorable neurological survival, followed
by the absence of adrenaline administration and age. The patients were categorized into 9 groups
with probabilities of favorable neurological survival ranging from 5.7 to 70.8% (areas under the
receiver operating characteristic curve of 0.851 and 0.844 in the development and validation cohorts,
respectively). Our model is potentially helpful in stratifying the probability of favorable neurological
survival in patients with witnessed OHCA and an initial shockable rhythm.
The prognosis of patients with out-of-hospital cardiac arrest (OHCA) has improved with the development of
prehospital and postcardiac arrest care, but OHCA remains a health concern w
orldwide1,2. Recently, practical
predictive scoring systems have been developed for evaluating the return of spontaneous circulation (ROSC),
overall survival, and favorable neurological survival, providing stratification of OHCAs and facilitating decisionmaking3–8. Bystander witness and initial shockable rhythm are well-known good predictors of resuscitation and
favorable neurological survival9,10. In addition, early defibrillation plays a crucial role in achieving ROSC in
patients with OHCA and a shockable r hythm11, in whom prehospital predictors of favorable outcomes may be
different from those in the entire OHCA population. The type of patients who would benefit most from early
therapeutic strategies, such as defibrillation, in an OHCA setting remains controversial.
The decision tree model developed using recursive partitioning analysis can uniquely provide the probability of a favorable neurological survival and risk stratification of OHCAs12, which is readily available in clinical
1
Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, 1‑8‑1 Inohana,
Chuo‑ku, Chiba, Chiba 260‑8677, Japan. 2Department of Biostatistics and Data Science, Graduate School
of Medicine, Osaka University, Osaka, Japan. 3Department of Cardiovascular Medicine, National Cerebral
and Cardiovascular Center, Osaka, Japan. 4Department of Public Health, Juntendo University School of
Medicine Tokyo, Tokyo, Japan. 5Department of Cardiovascular Medicine, Faculty of Medicine, Toho University,
Tokyo, Japan. 6Cardiovascular Medicine, Kawaguchi Cardiovascular and Respiratory Hospital, Saitama,
Japan. 7Department of Cardiology, Gifu University Graduate School of Medicine, Gifu, Japan. 8These authors
contributed equally: Kazuya Tateishi, Yuichi Saito, Yuichi Yasufuku and Atsushi Nakagomi. *email: kxtateishi@
gmail.com
Scientific Reports |
(2023) 13:16180
| https://doi.org/10.1038/s41598-023-43106-w
1
Vol.:(0123456789)
www.nature.com/scientificreports/
practice. Therefore, we aimed to identify the prehospital factors that would affect favorable neurological survival
in patients with witnessed OHCA and an initial shockable rhythm using the decision tree model.
Methods
Study design and population (data source)
In this retrospective observational study, we used prospectively collected nationwide data from patients with
OHCA in Japan based on the Utstein-style t emplate13,14. We identified patients aged ≥ 18 years who were transported to a hospital by emergency medical services (EMS) due to OHCA between January 2005 and December
2020. Patients were excluded based on the following criteria: (1) absence of a witness; (2) absence of an initial
shockable rhythm; and (3) unknown variable information (Fig. 1). The missing rates of the variables are shown
in Table S1.
This study complied with the Declaration of Helsinki regarding human investigations. The Ethics Committee
of Chiba University approved this study (unique identifier: #M10316). The requirement for written informed
consent has been waived by the Ethics Committee of Chiba University because the data were anonymized.
Emergency medical service system in Japan
Japan has approximately 800 fire stations with dispatch centers in 47 prefectures. The EMS system is under
the supervision of the Fire and Disaster Management Agency (FDMA). EMS personnel, in cooperation with
physicians, record data on OHCA patients using a Utstein-style template. The data are then integrated into the
National Registry System on the FDMA database server and are checked by the computer system. If any problems
are detected, data are sent back to the corresponding fire stations for correction. We utilized anonymous data
from the registry, including age, sex, witness, type of initial rhythm, type of bystander, public access automated
external defibrillator (AED), number of defibrillation attempts, waveforms of the defibrillator (i.e., monophasic
or biphasic), type of airway management device, and adrenaline use. Furthermore, prehospital ROSC, etiology
of cardiac arrest, 1-month survival, and neurological function were assessed using the cerebral performance
category (CPC) score at 1 month. In addition, information on the time course of collapse, initiation of cardiopulmonary resuscitation (CPR), prehospital ROSC, and arrival at the hospital was obtained.
According to Japanese g uidelines15, out-of-hospital EMS providers are not allowed to terminate resuscitation in the field. Therefore, all patients with OHCA treated by EMS providers are transported to a hospital. EMS
personnel are permitted to perform general medical treatments including the use of AED, basic airway adjuncts,
Figure 1. Study flow. EMS, emergency medical services; PEA, pulseless electrical activity; VF, ventricular
fibrillation; VT, ventricular tachycardia.
Scientific Reports |
Vol:.(1234567890)
(2023) 13:16180 |
https://doi.org/10.1038/s41598-023-43106-w
2
www.nature.com/scientificreports/
and peripheral intravenous catheters. Furthermore, the insertion of a tracheal tube and the administration of
intravenous adrenaline are allowed only under the instructions of a physician in the command center.
Definition and endpoints
The primary endpoint was a favorable neurological survival at 1 month, which was defined as survival with a
CPC score of 1 or 2 16. We also developed a decision tree model to predict survival at 1 month. Daytime admission was defined as admission to the hospital between 6:00 AM and 5:59 PM. Weekend/holiday admission was
defined as admission on a Saturday, Sunday, or Japanese national holiday.
Statistical analysis
Statistical analysis was performed using the Stata statistical software package version 15.1 (StataCorp LLC, Texas,
USA). Continuous variables are expressed as mean ± standard deviation and were compared using Student’s t-test.
Categorical data are presented as absolute numbers and percentages and were compared using the chi-square
test. Differences were considered statistically significant at p < 0.05.
The following 16 prehospital variables were selected for developing a prediction model: age (years old),
male (yes or no), collapse witnessed by EMS personnel (yes or no), bystander CPR by citizen (yes or no), chest
compression by citizen (yes or no), rescue breathing by citizen (yes or no), AED by citizen (yes or no), biphasic
defibrillator (yes or no), the number of defibrillation attempts (times), prehospital use of adrenaline (yes or no),
prehospital ROSC (yes or no), collapse-to-CPR time interval (min), collapse-to-first shock time interval (min),
collapse-to-hospital arrival time interval (min), daytime admission (yes or no), and weekend/holiday admission
(yes or no). Variables with “yes or no” were considered dichotomous.
To develop a decision tree model for the outcomes, we conducted a recursive partitioning analysis using the
Gini index17,18. Recursive partitioning analysis can provide a branching decision tree by dividing the patient
population into subgroups based on the analysis results of the relationship between outcomes and prehospital
variables19. We initially randomly divided all patients into the validation and development cohorts (a ratio of
1:9). Using the development cohort, tenfold cross-validation was then performed to generate a classification and
regression tree. Finally, the predictive ability of the classification and regression tree model was assessed in the
development and validation cohorts. ...