The aim of our study is to describe the characteristics of patients who use emergency medical services (EMS), EMS performance, and regional variations in Japan. Methods: We undertook a nationwide, population-based, descriptive review of anonymized ambulance transport records obtained from the Fire and Disaster Management Agency in Japan. All emergency patients transported to emergency medical institutions by EMS personnel from January to December 2016 were enrolled in this study, excluding patients who were not transported. Results: During the study period, 5,097,838 patients were transported to a hospital. Their median age was 69 years, 51.4% were male, and 56.5% were over 65 years old. Median durations from EMS call to EMS arrival on scene were similar among the regions, ranging from 7 to 9 min. However, the longest median duration from EMS call to hospital arrival was 38 min, and the shortest was 31 min across the regions. Among all patients, 350,865 (6.9%) were assessed as being in a severe condition, 14,410 (0.3%) were in very severe condition, and 74,780 (1.5%) were confirmed to be dead at the time of initial medical examination in the emergency department. Conclusions: We described the characteristics of emergency patients and EMS performance in Japan. This registry serves as a basis for providing relevant information to improve prehospital emergency medical systems.

Background: There is a paucity of information for predicting patient outcomes other than the American Association for the Surgery of Trauma (AAST) renal injury scale. The aim of this study was to evaluate the association between the patient characteristics and outcomes of patients with blunt renal trauma using a nationwide database in Japan. Methods: We performed a retrospective analysis of the Japan Trauma Data Bank (JTDB) from 2004 to 2018. We identified patients with blunt renal trauma by AIS codes converted to AAST grades. We evaluated trends in patient characteristics and management and assessed factors associated with mortality and nephrectomy using a multivariable logistic regression analysis. Results: We identified 3550 patients with blunt renal trauma. Their median age was 43 years and 74.2% were male. Nephrectomy was performed in 3.8%, and the overall mortality rate was 9.5%. We found increasing trends in age and emergency abdominal angiography and decreasing trends in nephrectomy and mortality over the 15-year period. The following factors were associated with mortality: age ≥ 65 years (adjusted OR 3.36); pedestrian accident (adjusted OR 1.94); fall from height (adjusted OR 1.91); shock on arrival (adjusted OR 4.02); concomitant injuries to the head/neck (adjusted OR 3.14), pelvis/lower-extremity (adjusted OR 1.59), liver (adjusted OR 1.68), spleen (adjusted OR 1.45), and gastrointestinal tract (adjusted OR 1.90); AAST grades III-V (adjusted ORs 1.42, 2.16, and 5.55); and emergency abdominal angiography (adjusted OR 0.70). The following factors were associated with nephrectomy: shock on arrival (adjusted OR 1.98), concomitant injuries to the thorax (adjusted OR 0.46) and spleen (adjusted OR 2.07), AAST grades III, IV, and V (adjusted ORs 18.40, 113.89, and 468.17), and emergency abdominal angiography (adjusted OR 0.28). Conclusions: We demonstrated that the AAST grade and emergency angiography were associated with mortality and nephrectomy in blunt renal trauma in the Japanese population.

The impact of time of day or day of week on the survival of emergency trauma patients is still controversial. The purpose of this study was to evaluate the outcomes of these patients according to time of day or day of week of emergency admission by using data from the nationwide Japan Trauma Data Bank (JTDB). This study enrolled 236,698 patients registered in the JTDB database from 2004 to 2015, and defined daytime as 09:00 am to 16:59 pm and nighttime as 17:00 pm to 08:59 am, weekdays as Monday to Friday, and weekends as Saturday, Sunday, and national holidays. The outcome measures were death in the emergency room (ER) and discharge to death. In total, 170,622 patients were eligible for our analysis. In a multivariable logistic regression adjusted for confounding factors, both death in the ER and death at hospital discharge were significantly lower during the daytime than at nighttime (623/76,162 [0.82%] vs 954/94,460 [1.01%]; adjusted odds ratio [AOR] 0.79; 95% confidence interval [CI] 0.71–0.88 and 5765/76,162 [7.57%] vs 7270/94,460 [7.70%]; AOR 0.88; 95% CI 0.85–0.92). In contrast, the weekdays/weekends was not significantly related to either death in the ER (1058/114,357 [0.93%] vs 519/56,265 [0.92%]; AOR 0.95; 95% CI 0.85–1.06) or death at hospital discharge (8975/114,357 [7.85%] vs 4060/56,265 [7.22%]; AOR 1.02; 95% CI 0.97–1.06). In this population of emergency trauma patients in Japan, both death in the ER and death at hospital discharge were significantly lower during the daytime than at night, but the weekdays/weekends was not associated with outcomes of these patients.

Aim: Details such as diagnosis and outcome of patients transported by ambulance after telephone triage have not been fully revealed. The aim of this study was to reveal profile and outcome about patients transported by ambulance via telephone triage with dataset of telephone triage and population-based registry for emergency patients. Methods: This retrospective descriptive study with a one-year study period from January 1, 2016 to December 31, 2016 included patients selected from the telephone triage dataset who were transported by ambulance. Key parameters such as age, sex and date and time of ambulance dispatch were used to identify patient data from the ORION registry. We assessed the profile and outcome of the patients in a descriptive epidemiological analysis. Results: We included 4,293 patients in the selected datasets whose data were merged, of whom 2,998 patients (69.8%) returned home from the emergency department, 1,255 (29.2%) were hospitalized, 32 (0.7%) were transferred to other hospitals, and 8 (0.2%) died. The most common diagnosis in the emergency departments was "infectious gastroenteritis and colitis, unspecified [A09] (219, 5.1%)". Among the 1,255 hospitalized patients, 905 patients (72.1%) were discharged home, 254 patients (20.2%) remained hospitalized, 52 patients (4.1%) were transferred to other hospitals, 38 patients (3.0%) died, and 5 patients (0.5%) had missing data. The most common diagnosis was "cerebral infarction [I63.0-I63.9] (138, 11.0%)". Conclusion: This study revealed the profile and outcome of patients transported by ambulance after telephone triage.

Background Trauma is a heterogeneous condition, and specific clinical phenotypes may identify target populations that could benefit from certain treatment strategies. In this retrospective study, we determined clinical phenotypes and identified new target populations of trauma patients and their treatment strategies. Methods We retrospectively analyzed datasets from the Japan Trauma Data Bank and determined trauma death clinical phenotypes using statistical machine learning techniques and evaluation of biological profiles. Results The analysis included 71,038 blunt trauma patients [median age, 63 (interquartile range [IQR], 40–78) years; 45,479 (64.0%) males; median Injury Severity Score, 13 (IQR, 9–20)], and the derivation and validation cohorts included 42,780 (60.2%) and 28,258 (39.8%) patients, respectively. Of eight derived phenotypes (D-1–D-8), D-8 (n = 2178) had the highest mortality (48.6%) with characteristic severely disturbed consciousness and was further divided into four phenotypes: D-8α, multiple trauma in the young (n = 464); D-8β, head trauma with lower body temperature (n = 178); D-8γ, severe head injury in the elderly (n = 957); and D-8δ, multiple trauma, with higher predicted mortality than actual mortality (n = 579). Phenotype distributions were comparable in the validation cohort. Biological profile analysis of 90 trauma patients revealed that D-8 exhibited excessive inflammation, including enhanced acute inflammatory response, dysregulated complement activation pathways, and impaired coagulation, including downregulated coagulation and platelet degranulation pathways, compared with other phenotypes. Conclusions We identified clinical phenotypes with high mortality, and the evaluation of the molecular pathogenesis underlying these clinical phenotypes suggests that lethal trauma may involve excessive inflammation and coagulation disorders.

BACKGROUND There have been no clinical studies to sufficiently reveal the interaction effect generated by combinations of injury regions of multiple injuries. We hypothesized that certain combinations of trauma regions might lead to increased risk of traumatic death and aimed to verify this hypothesis using a nationwide trauma registry in Japan. MATERIALS AND METHODS This was a retrospective study of trauma patients registered in the Japan Trauma Data Bank between 2004 and 2017. We included patients who suffered blunt trauma with an Injury Severity Score of 16 or more. The trauma was classified into four regions (head, chest, abdomen, and extremities), and a multivariable logistic regression analysis was performed that included interaction terms derived from the combination of two regions as covariates. RESULTS We included 78,280 trauma patients in this study. Among them, 16,100 (20.6%) patients were discharged to death. Multivariable logistic regression showed the odds ratio (OR) of in-hospital death compared with patients without injury of an Abbreviated Injury Scale score of 3 or more in each injured region as follows: head score, 2.31 (95% confidence interval [CI], 2.13–2.51); chest score, 2.28 (95% CI, 2.17–2.39); abdomen score, 1.68 (95% CI, 1.56–1.82); and extremities score, 1.84 (95% CI, 1.76–1.93), respectively. In addition, the ORs of the statistically significant interaction terms were as follows: head-chest 1.29 (95% CI, 1.13–1.48), chest-abdomen 0.77 (95% CI, 0.67–0.88), chest-extremities 1.95 (95% CI, 1.77–2.14), and abdomen-extremities 0.70 (95% CI, 0.62–0.79), respectively. CONCLUSION In this population, among patients with multiple injuries, a combination of head-chest trauma and chest-extremities trauma was shown to increase the risk of traumatic death. LEVEL OF EVIDENCE Prognostic, Level III.

Purpose Posttraumatic meningitis is one of the severe complications that can result in increased mortality and longer hospital stay among trauma patients. Factors such as cerebrospinal fluid (CSF) fistula and basilar skull fracture are associated with posttraumatic meningitis. However, it remains unclear whether procedures such as burr hole surgery in the emergency department and decompressive craniectomy are associated with posttraumatic meningitis. The aim of this study was to assess factors associated with posttraumatic meningitis with a nationwide hospital-based trauma registry in Japan. Methods This was a retrospective observational study with a 12-year study period from January 2004 to December 2015. We included trauma patients registered in the Japanese Trauma Data Bank, whose head Abbreviated Injury Scale score was ≥ 3 in this study. The main endpoint was the occurrence of meningitis during hospitalization. Multivariable logistic regression analysis was used to assess independent parameters associated with posttraumatic meningitis such as CSF fistula, burr hole surgery in the emergency department, and decompressive craniectomy. Results Among 60,390 head injury patients with head AIS score 3 or more, 284 (0.5%) patients had posttraumatic meningitis. Factors associated with posttraumatic meningitis were burr hole surgery in the emergency department (adjusted odds ratio [AOR] 2.158 [95% confidence interval (CI) 1.401-3.325]), decompressive craniectomy (AOR 2.123 [95% CI 1.506-2.993]), external ventricular drainage (AOR 1.843 [95% CI, 1.157-2.935]), CSF leakage (AOR 3.328 [95% CI 2.205-5.022]), and basilar skull fracture (AOR 1.651 [95% CI 1.178-2.314]).Conclusions In this population of trauma patients, burr hole surgery in the emergency department and decompressive craniectomy was associated with posttraumatic meningitis.

Background COVID-19 is now a common disease, but its pathogenesis remains unknown. Blood circulating proteins reflect host defenses against COVID-19. We investigated whether evaluation of longitudinal blood proteomics for COVID-19 and merging with clinical information would allow elucidation of its pathogenesis and develop a useful clinical phenotype. Methods To achieve the first goal (determining key proteins), we derived plasma proteins related to disease severity by using a first discovery cohort. We then assessed the association of the derived proteins with clinical outcome in a second discovery cohort. Finally, the candidates were validated by enzyme-linked immunosorbent assay in a validation cohort to determine key proteins. For the second goal (understanding the associations of the clinical phenotypes with 28-day mortality and clinical outcome), we assessed the associations between clinical phenotypes derived by latent cluster analysis with the key proteins and 28-day mortality and clinical outcome. Results We identified four key proteins (WFDC2, GDF15, CHI3L1, and KRT19) involved in critical pathogenesis from the three different cohorts. These key proteins were related to the function of cell adhesion and not immune response. Considering the multicollinearity, three clinical phenotypes based on WFDC2, CHI3L1, and KRT19 were identified that were associated with mortality and clinical outcome. Conclusion The use of these easily measured key proteins offered new insight into the pathogenesis of COVID-19 and could be useful in a potential clinical application.