Fig 1.
Overview of the data partitioning and stratified cross-validation method and neural network-based machine learning model.
The model was developed using the stratified cross-validation method with CPC1/2. The machine learning model comprised a three-layer neural network, along with class weighting to improve the predictive precision for imbalanced data. CPC, cerebral performance category; BN, batch normalization; AUROC, area under the receiver operating characteristics curve.
Fig 2.
EMS, emergency medical services; OHCA, out-of-hospital cardiopulmonary arrest.
Table 1.
Overall patient background and comparison between five groups classified by CPC1/2.
Fig 3.
Modification of single factors changes the predicted CPC1/2.
Changes in predicted outcome obtained by modifying a single factor. A higher age worsened the prognosis, and vice versa. Time delay worsened the prognosis, whereas reducing the duration improved the prognosis. CPC, cerebral performance category.
Fig 4.
Modification of time from ambulance contact to hospital arrival and first defibrillation.
The square box indicates no adjustments. The two ends of the color spectrum show a 6% increase and decrease in predicted CPC1/2, respectively. Overall, reducing the time for hospital arrival improved outcomes, whereas delays worsened them. A reduced time to defibrillation strengthened this trend, but it was obscured when the time to defibrillation was reduced by more than 3 min or delayed by more than 2 min. CPC, cerebral performance category.
Fig 5.
Modification of times from ambulance contact to hospital arrival and first-drug administration.
The square box indicates no adjustments. The two ends of the color spectrum show a 6% increase and decrease in predicted CPC1/2, respectively. Overall, reducing the time for hospital arrival improved outcomes, whereas delays worsened them. Reducing the time to drug administration strengthened the effect of reducing the transport time, but reducing the transport time improved the prognosis even with delayed drug administration. CPC, cerebral performance category.