The relationship between fine particulate matter (PM2.5) and schizophrenia severity

PURPOSE

Although particulate matter (PM) is reported to affect the rate of emergency admissions for schizophrenia, no study has examined the relationship between particulate matter less than 2.5 μm in diameter (PM_2.5) and the severity of schizophrenia.

METHODS

We obtained data on patients with schizophrenia at a psychiatric hospital, and on air pollution in Sakai, Japan between Feb 1, 2013 and April 30, 2016. Multivariate logistic regression analyses were used to estimate the relationship between PM_2.5 concentrations and scores on the Brief Psychiatric Rating Scale (BPRS) of schizophrenia patients at admission, with a lag of up to 7 days.

RESULTS

During the study period, there were 1193 schizophrenia cases. The odds ratio (OR) for a BPRS score ≥ 50 at admission was 1.05 [95% confidence interval 1.00-1.10] and the effect of PM_2.5 concentration was significant for lag period of 2 days. The ORs associated with PM_2.5 concentration increased substantially for patients over 65 years of age.

CONCLUSIONS

Ambient PM_2.5 concentration was associated with exacerbation of schizophrenia. Our results suggest that protection for several days should be considered for controlling PM_2.5-related schizophrenia, especially among elderly patients.

Decrease in the prevalence of extended-spectrum cephalosporin-resistant Salmonella following cessation of ceftiofur use by the Japanese poultry industry

Extended-spectrum cephalosporin (ESC)-resistant Salmonella in chicken meat is a significant food safety concern. We previously reported that the prevalence of ESC-resistant Salmonella in chicken meat, giblets, and processed chicken (chicken meat products) increased in Japan between 2005 and 2010, with 27.9% (17/61) of Salmonella isolated from chicken meat products in 2010 showing resistance to ESC. The aims of the present study were to clarify trends in the prevalence of ESC-resistant Salmonella in chicken meat products in Japan between 2011 and 2015, and to determine the genetic profiles of bla-harboring plasmids, including replicon types, using next-generation sequencing. Our results showed that the prevalence of ESC-resistant Salmonella, mainly consisting of AmpC β-lactamase CMY-2-producing isolates, in chicken meat products had increased to 45.5% (10/22) by 2011. However, following the voluntary cessation of ceftiofur use by the Japanese poultry industry in 2012, the prevalence of ESC-resistant Salmonella steadily decreased each year, to 29.2% (7/24), 18.2% (4/22), 10.5% (2/19), and 10.5% (2/19) in 2012, 2013, 2014, and 2015, respectively. Furthermore, no AmpC β-lactamase CMY-2-producing isolates were identified in 2014 and 2015. However, the prevalence of Salmonella enterica subspecies enterica serovar Manhattan isolates harboring a bla_TEM-52-carrying IncX1 plasmid remained steady even after the cessation of ceftiofur use. Therefore, continuous monitoring of ESC resistance amongst Salmonella isolates from chicken meat products is required for food safety.

Comparing intracerebral hemorrhages associated with direct oral anticoagulants or warfarin

OBJECTIVES

This cross-sectional survey explored the characteristics and outcomes of direct oral anticoagulant (DOAC)-associated nontraumatic intracerebral hemorrhages (ICHs) by analyzing a large nationwide Japanese discharge database.

METHODS

We analyzed data from 2,245 patients who experienced ICHs while taking anticoagulants (DOAC: 227; warfarin: 2,018) and were urgently hospitalized at 621 institutions in Japan between April 2010 and March 2015. We compared the DOAC- and warfarin-treated patients based on their backgrounds, ICH severities, antiplatelet therapies at admission, hematoma removal surgeries, reversal agents, mortality rates, and modified Rankin Scale scores at discharge.

RESULTS

DOAC-associated ICHs were less likely to cause moderately or severely impaired consciousness (DOAC-associated ICHs: 31.3%; warfarin-associated ICHs: 39.4%; p = 0.002) or require surgical removal (DOAC-associated ICHs: 5.3%; warfarin-associated ICHs: 9.9%; p = 0.024) in the univariate analysis. Propensity score analysis revealed that patients with DOAC-associated ICHs also exhibited lower mortality rates within 1 day (odds ratio [OR] 4.96, p = 0.005), within 7 days (OR 2.29, p = 0.037), and during hospitalization (OR 1.96, p = 0.039).

CONCLUSIONS

This nationwide study revealed that DOAC-treated patients had less severe ICHs and lower mortality rates than did warfarin-treated patients, probably due to milder hemorrhages at admission and lower hematoma expansion frequencies.

Abstract WP15: Stent Retriever Thrombectomy After Intravenous Tissue Plasminogen versus Intravenous Tissue Plasminogen Activator Alone In Japan : J-ASPECT Japan

Objective: We performed a nationwide study to evaluate the effectiveness of stent-retriever in addition to intravenous thrombolysis in acute ischemic stroke patients in the ‘‘real-world’’ settings.

Methods: This was a retrospective cohort study using the Diagnosis Procedure Combination nationwide inpatient database in Japan. Patients with acute ischemic stroke who were admitted to hospitals between April 1, 2013, and March 31, 2014 were identified. The rate of functional independence (modified Rankin scale score, 0 to 2) at discharge and mortality at 30 days were compared between patients who received intravenous thrombolysis alone (IVT group) and those who received stent-retriever after intravenous thrombolysis (IVET group) using 1:1 propensity score-matching.

Results: In total, 71,519 acute ischemic patients were identified in a year. Among those, 3,367 patients were eligible (3,110 in IVT group and 257 in IVET group). Post-matching, 134 pairs of patients were analysed. The rate of functional independence at discharge was higher in IVET group than in IVT group (odds ratio 1.96, 95% CI 1.16-3.35; p=0.012). In addition, there was no significant differences in mortality at 30 days between the two groups (odds ratio 1.80, 95% CI 0.81-4.23; p=0.153).

Conclusion: This nationwide study revealed that mechanical thrombectomy with stent-retriever in addition to intravenous thrombolysis improves functional outcomes in patients with acute ischemic stroke, and with no evidence of increased mortality. A randomized clinical trial seems warranted.

Abstract WP244: Current Status and Issues in Prehospital Care for Stroke in Japan: A Nationwide Fire Department Questionnaire Survey

Background and purpose: In the rapidly aging society of Japan, improvement of the emergency medical care system for stroke is an urgent concern. In prehospital care for stroke, appropriate triage, selection of the delivery facility, and decreased transport time contribute directly to prognosis. The standard treatment for acute ischemic stroke (AIS) has changed dramatically. With the introduction of new thrombectomy devices, proper placement of comprehensive stroke centers (CSCs) should be reconsidered. Accordingly, a nationwide survey is needed to develop an efficient prehospital care system. The aim of this study was to elucidate problems in prehospital care for stroke in Japan, using a nationwide fire department (FD) questionnaire survey.

Materials and methods: We conducted a questionnaire survey of 733 FDs in Japan with the cooperation of the Japanese Society of Emergency Medicine and the Emergency Planning Office of the Fire and Disaster Management Agency. The questionnaires evaluated utilization status of the Prehospital Stroke Life Support (PSLS) protocol and prehospital stroke scale (PSS), awareness of standard treatment with new devices, information on delivery facilities and transportation, use of information and communication technology (ICT), and the retraining system for paramedics.

Results: Data obtained from 664 FDs (91%) were analyzed. The PSLS protocol and PSS were used by 47.2% and 59.6%, respectively. Surprisingly, only 35.6% of FDs had knowledge about the latest treatment for AIS, and half of the FDs did not have an opportunity to learn about treatment. The proportion of FDs with a CSC in their jurisdictions was decreased in rural areas compared with urban areas (19.2% vs. 49.8%). However, helicopter transportation and ICT were not adequately utilized even in rural areas. Only half of the FDs urged paramedics to attend a PSLS course.

Conclusion: We demonstrated problems with prehospital care for stroke in Japan using a nationwide FD questionnaire survey. Placement of CSCs, adequacy of the transportation system, and communication between physicians and paramedics should be reevaluated.

Abstract WP266: Associations Between Temporal Improvement of Stroke Care Capabilities and Functional Outcome in Acute Ischemic Stroke: J-aspect Study

Introduction: Certification system of the primary and comprehensive stroke center (PSC and CSC) is still under discussion in Japan. This study attempts to examine associations between the variation of stroke center capabilities and the improvement of outcomes for acute ischemic stroke on a national scale.

Hypothesis: Improvements in hospital stroke center capabilities leads to better outcome of acute ischemic stroke patients.

Methods: Using a validated score for evaluating CSC capabilities, which consists of 5 categories (personnel, diagnostic techniques, specific expertise, infrastructure, and education) on a 25 point scale, we assessed CSC capabilities for 137 certified training hospitals in 2011 and 2015 (Kada et al. BMC Neurol 2017). A consecutive health insurance claims data known as the Japanese Diagnosis Procedure Combination/Per Diem Payment Systems of 2011 and 2015 was obtained from the hospitals. The proportion of favorable outcome—score 0 to 1 on the modified Rankin Scale (mRS)—at discharge was quantified as the primary outcome. The change in CSC score with more than two points over time was quantified as an independent variable. We regressed the change of CSC score on morbidity with adjustment of average age and sex in the hospitals.

Results: In total, 18,658 in 2011 and 29,999 in 2015 ischemic stroke patients were admitted to 137 hospitals. Median annual number of ischemic stroke patients per hospital increased from 115 to 183 over time. Mean age (74.5 year vs 74.2 years) and proportions of men (56.8% vs 58.2%) were almost the same. The mean CSC scores increased from 15.9±4.0/25 to 17.2±4.2/25 point. The mean hospital mortality decreased from 6.1% to 4.3%. The mean proportion of patients with the favorable outcome at discharge increased from 39.2% to 45.5%. We selected random-effect model based on Housman test. In regression analyses, the increase of CSC score over time was significantly associated with the increasing proportion of the favorable outcome at discharge (coefficient, 2.76; 95% CI, 0.04-5.47; p-value, 0.047).

Conclusions: Improvements in CSC capabilities overtime was significantly related to the improvement of functional outcome at discharge in ischemic stroke patients.

Abstract WP268: Associations Between Case Volume and Outcomes in the Subarachnoid Hemorrhage Patients With Clipping or Coiling: J-ASPECT Study

Background: Many studies have reported that high-volume center was associated with the favorable outcomes in subarachnoid hemorrhage (SAH) patients with treatment. However, in Japan, the effect of the case volume of the hospital in SAH patients remains elusive. The aim of this study is to investigate the associations between case volume and outcomes of clipping or coiling using data obtained from the Japanese Diagnosis Procedure Combination [DPC]-based Payment System.

Methods: Of the 847 certified training institutions of the Japan Neurosurgical Society, 327 institutions agreed to participate in this DPC discharge database study. Data on patients hospitalized for SAH between April 1, 2012 and March 31, 2013 were obtained from the DPC database. Patients hospitalized because of SAH were identified using International Classification of Diseases-10 diagnosis codes (I60.0-9). The case volumes of clipping and coiling in each hospital were divided into quintiles (Q1-Q4). Odd ratios (ORs) of in-hospital mortality and modified Rankin Scale (mRS) at discharge were estimated after adjustment for age, sex, comorbidities, and SAH severity. The category of Q1 was assigned a reference for OR.

Results: A total of 5214 patients with SAH (3624 clipping, 1590 coiling) were analyzed. Mortality was 9.8%, and proportion of discharge mRS3-6 was 44.0%. No significant associations were found between case volume and in-hospital mortality in both the clipping (Q2, Q3, and Q4; OR = 0.97, 0.69, and 0.77; P = 0.902, 0.148, and 0.263) and coiling group (Q2, Q3, and Q4; OR = 0.94, 1.62, and 0.84; P = 0.864, 0.140, and 0.586). No significant associations were found between case volume and discharge mRS3-6 in both the clipping (Q2, Q3, and Q4; OR = 1.28, 1.27, and 1.09; P = 0.194, 0.189, and 0.619) and coiling group (Q2, Q3, and Q4; OR = 0.89, 1.15, and 0.78; P = 0.691, 0.599, and 0.315).

Conclusion: In Japan, case volume did not show the correlation with outcomes in SAH patients. This nationwide database study reflects the real-world practice. <!--EndFragment-->

Abstract TP7: Effect of Tissue Plasminogen Activator or Endovascular Thrombectomy for Mortality of Acute Ischemic Stroke in Nationwide Hospital Cohort : J-ASPECT Study

Introduction: In recent years, the treatment of the acute phase of cerebral infarction such as tPA and endovascular thrombectomy has been rapidly changing, and development of a medical system for acute cerebral infarction is desired.

Objective: To examine the effect of tPA and endovascular thrombectomy on mortality in patients with acute ischemic stroke in the nationwide 5 years hospital cohort in Japan.

Methods: We conducted annual nationwide survey from 2011 to 2015 using data from the Japanese Diagnosis Procedure Combination database on patients hospitalized with ischemic and hemorrhagic stroke in a nationwide hospital cohort in Japan (J-ASPECT Study). The effect of tPA or endovascular thrombectomy on stroke mortality was analyzed by mixed effect model with years (from 2011 to 2015), age, gender, Japan Coma Scale (JCS), and Comprehensive stroke care (CSC) score as a fixed effect, and hospital as a random effect. CSC score was developed by our study group based on the institutional survey conducted in 2011.

Results: The total numbers of patients were 292,230 in ischemic stroke. In 5 years, the proportion of tPA or endovascular thrombectomy has increased from 7.2% to 8.4%, while the mortality has decreased from 7.6% to 5.5%. The mortality varied by JCS, which was 37.5% for JCS 3 digit, 15.4% for JCS 2 digit, 4.8% for JCS 1 digit and 1.4% for JCS 0 in 2015. In the analysis of subjects with severe JCS 3 digit, years (OR = 0.97, 95% CI = 0.94 - 1.00), CSC score increase (0.98, 95% CI = 0.97 - 0.99), and tPA or endovascular thrombectomy (OR = 0.75, 95% CI = 0.67 - 0.84) were found to reduce the risk of death.

Conclusion: According to the analysis of patients with acute ischemic stroke for 5 years, tPA or endovascular thrombectomy was related to reduced mortality in subjects with high severity.

Migraine-preventive prescription patterns by physician specialty in ambulatory care settings in the United States

Many adults with migraine who require preventive therapy are often not prescribed the proper medications. The most likely reason is that primary care physicians are unacquainted with preventive medications for migraine. The present study assessed the migraine-preventive prescription patterns in office visits using data from the National Ambulatory Medical Care Survey from 2006 to 2009 in the United States. Patients who were 18 years or older and diagnosed with migraine were included in the analysis. In accordance with the recommendations of the headache guidelines, we included beta-blockers, antidepressants, triptans for short-term prevention of menstrual migraine, and other triptans for acute treatment. Weighted visits of adults with migraine prescribed with preventive medication ranged from 32.8% in 2006 to 38.6% in 2009. Visits to primary care physicians accounted for 72.6% of the analyzed adult migraine visits. Anticonvulsants (odds ratio [OR] 0.29, 95% confidence interval [CI] 0.14–0.57, p < 0.001) and triptans for menstrual migraine (OR 0.50, 95% CI 0.28–0.91, p = 0.025) were less frequently prescribed by primary care physicians compared with specialty care physicians, such as neurologists and psychiatrists. There were no significant differences in the prescription patterns of antidepressants and beta-blockers between primary and specialty care physicians. Beta-blockers were prescribed to patients with comorbidity of hypertension, and antidepressants were used by patients with comorbidity of depression. There are differences in the prescription patterns of certain type of preventive medications between primary care physicians and specialty care physicians.

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Anticonvulsants were less used by primary care physicians than specialty care physicians.

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Triptans for prevention were also less used by primary care physicians.

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No differences were found in patterns of antidepressants and beta-blockers.

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Beta-blockers were used for patients with comorbidity of hypertension.

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Antidepressants were used for patients with comorbidity of depression.

Interaction of defibrillation waveform with the time to defibrillation or the number of defibrillation attempts on survival from out-of-hospital cardiac arrest

AIM

Early biphasic defibrillation is effective in out-of-hospital cardiac arrest (OHCA) cases. In the resuscitation of patients with OHCA, it is not clear how the defibrillation waveform interacts with the time to defibrillation to influence patient survival. The second, and any subsequent, shocks need to be administered by an on-line physician in Japan. Thus, we investigated the interaction between the defibrillation waveform and time to or the number of defibrillation on resuscitation outcomes.

METHODS

This prospective observational study used data for all OHCAs that occurred between 2005 and 2014 in Japan. To investigate the interaction effect between the defibrillation waveform and the time to defibrillation or the number of defibrillations on the return to spontaneous circulation (ROSC), 1-month survival, and cerebral performance category (CPC) (1, 2), we assessed the modifying effects of the defibrillation waveform and the time to or the number of defibrillation on additive scale (i.e., the relative excessive risk due to interaction, RERI) and multiplicative scale (i.e., ratio of odds ratios (ORs)).

RESULTS

In total, 71,566 cases met the inclusion criteria. For the measure of interaction between the defibrillation waveform and the time to defibrillation, ratio of ORs for ROSC was 0.84 (0.75-0.94), implying that the effect of time to first defibrillation on ROSC was negatively modified by defibrillation waveform. For the interaction between the defibrillation waveform and the number of defibrillations, RERI and ratio of ORs for CPC (1, 2) was -0.25 (-0.47 to -0.06) and 0.79 (0.67-0.93), respectively. It is implied that the effect of number of defibrillation on CPC (1, 2) was negatively modified by defibrillation waveform.

CONCLUSIONS

An increased number of defibrillations was associated with a decreased ROSC in the case of biphasic and monophasic defibrillation, while an increased number of defibrillations was related to an increased 1-month survival rate and CPC (1, 2) only in the case of biphasic defibrillation. When two or more defibrillations were performed, a biphasic waveform was more effective in terms of long-term survival than a monophasic waveform.

Pulsed-field profile diversities of Salmonella Enteritidis, S. Infantis, and S. Corvallis in Japan

The diversity of pulsed-field profiles (PFPs) within non-typhoidal Salmonella subtypes influences epidemiological analyses of Salmonella outbreaks. Therefore, determining the PFP diversity of each Salmonella serovar is important when evaluating current circulating strains. This study examined the PFP diversity of three important public health Salmonella enterica subspecies enterica serovars, S. Enteritidis (n=177), S. Infantis (n=205), and S. Corvallis (n=90), using pulsed-field gel electrophoresis. Isolates were collected from several sources, primarily from chicken-derived samples, in the Kyushu-Okinawa region of Japan between 1989 and 2005. S. Enteritidis isolates displayed 51 distinct PFPs (E-PFPs), with 92 (52.0%) and 32 (18.1%) isolates displaying types E-PFP1 and E-PFP10, respectively. The 205 S. Infantis isolates showed 54 distinct PFPs (I-PFPs), with 87 (42.4%) and 36 (17.6%) isolates being I-PFP4 and I-PFP2, respectively. I-PFP18 was the dominant I-PFP of layer chicken isolates across a 5-year period. Fourteen distinct S. Corvallis PFPs were detected. Simpson’s index results for the genetic diversities of S. Enteritidis, S. Infantis, and S. Corvallis isolates were 0.70, 0.79, and 0.78, respectively. None of the E-PFPs or I-PFPs of layer chicken isolates overlapped with those of broiler chicken isolates, and the dominant clonal lines existed for >10 years. In conclusion, limited PFP diversities were detected amongst S. Enteritidis, S. Infantis, and S. Corvallis isolates of primarily chicken-derived origins in the Kyushu-Okinawa region of Japan. Therefore, it is important to take into account these limitations in PFP diversities in epidemiological analyses of Salmonella outbreaks.

Simultaneous oral administration of Salmonella Infantis and S. Typhimurium in chicks

Background

To confirm the hypothesis that Salmonella enterica subspecies enterica serovar (S.) Infantis has higher basic reproductive rates in chicks compared with other Salmonella serovars, 1-day-old specific-pathogen-free chicks (n = 8) were challenged simultaneously with S. Infantis and S. Typhimurium per os. Challenged chicks (Group A) were then housed with non-infected chicks (Group B, n = 4) for 6 days (from 2 to 8 days of age). Group B birds were then housed with other non-infected birds (Group C, n = 4), which were then transferred to cages containing a further group of untreated chicks (Group D, n = 2). A control group consisting of four non-infected chicks was used for comparison. All chickens were humanely sacrificed at 18 days of age, and Salmonella from bowel and liver samples were enumerated.

Results

Both serovars were isolated from all groups except the control group. S. Typhimurium was isolated at a greater frequency than S. Infantis from the bowel samples of chicks from Groups B, C and D, while no differences in colonisation rates were observed between the two serovars in liver samples from Groups B, C and D. S. Typhimurium, but not S. Infantis, was immunohistochemically detected in the lamina propria of the cecum and rectum in five birds of Group A. Despite the competitive administration, neither of the two serovars completely excluded the other, and no differences were observed in basic reproductive rates between the two serovars.

Conclusions

These findings, together with data from previous studies, suggest that the initial quantitative domination of S. Infantis in chicken flocks may explain why this serovar is predominant in broiler chickens.

Age × Gender Interaction Effect on Resuscitation Outcomes in Patients With Out-of-Hospital Cardiac Arrest

Although an interaction between gender and age has been shown to influence resuscitation outcomes in patients with out-of-hospital cardiac arrest (OHCA), this interaction has not been investigated in Asian populations. In this prospective, observational study, data from all cases of OHCA in Japan between 2005 and 2012 were obtained from the Japanese National Registry. We determined the relative excess risk due to interaction and the ratio of odds ratios (ORs) to assess the interaction effect of gender and age on the incidence of return of spontaneous circulation (ROSC) before hospital arrival, 1-month survival, and neurologically intact survival 1 month after OHCA. Male gender was associated with decreased ROSC and lower 1-month survival rates in patients with OHCA of presumed cardiac origin. Older age was associated with lower 1-month and neurologically intact survival rates in male patients with OHCA of presumed cardiac and noncardiac origin and with increased ROSC in male patients with OHCA of presumed cardiac origin. The relative excess risk due to interaction for ROSC in patients with OHCA of presumed cardiac origin was statistically significant (OR 0.19, 95% confidence interval [CI] 0.06 to 0.32). The ratio of ORs for ROSC was statistically significant in patients with OHCA of presumed cardiac origin (OR 1.25, 95% CI 1.05 to 1.47) and of noncardiac origin (OR 0.40, 95% CI 0.17 to 0.92). In conclusion, the interaction effect between age and gender on ROSC was positive in OHCA cases of presumed cardiac origin and negative in those of noncardiac origin.

Effects of advanced life support on patients who suffered cardiac arrest outside of hospital and were defibrillated

BACKGROUND

The effects and relative benefits of advanced airway management and epinephrine on patients with out-of-hospital cardiac arrest (OHCA) who were defibrillated are not well understood.

METHODS

This was a prospective observational study. Using data of all out-of-hospital cardiac arrest cases occurring between 2005 and 2013 in Japan, hierarchical logistic regression and conditional logistic regression along with time-dependent propensity matching were performed. Outcome measures were survival and minimal neurological impairment [cerebral performance category (CPC) 1 or 2] at 1month after the event.

RESULTS

We analyzed 37,873 cases that met the inclusion criteria. Among propensity-matched patients, advanced airway management and/or prehospital epinephrine use was related to decreased rates of 1-month survival (adjusted odds ratio 0.88, 95% confidence interval 0.80 to 0.97) and CPC (1, 2) (adjusted odds ratio 0.56, 95% confidence interval 0.48 to 0.66). Advanced airway management was related to decreased rates of 1-month survival (adjusted odds ratio 0.89, 95% confidence interval 0.81to 0.98) and CPC (1, 2) (adjusted odds ratio 0.54, 95% confidence interval 0.46 to 0.64) in patients who did not receive epinephrine, whereas epinephrine use was not related to the outcome measures.

CONCLUSIONS

In defibrillated patients with OHCA, advanced airway management and/or epinephrine are related to reduced long-term survival, and advanced airway management is less beneficial than epinephrine. However, the proportion of patients with OHCA who responded to an initial shock was very low in the study subjects, and the external validity of our findings might be limited.

Spatiotemporal variations of extreme low temperature for emergency transport: a nationwide observational study

Although recent studies have investigated the effect of extreme heat on emergency transport, few have investigated the spatiotemporal variations of extreme low temperature for emergency transport on a national scale. Data pertaining to emergency ambulance transport and weather variation in the 47 prefectures of Japan between 2007 and 2010 were obtained. Nonlinear and delayed relationships between temperature and morbidity were assessed using a two-stage analysis. First, a Poisson regression analysis allowing for overdispersion in a distributed lag nonlinear model was used to estimate the prefecture-specific effects of temperature on morbidity. Second, a multivariate meta-analysis was applied to pool estimates on a national level. Of 15,868,086 emergency transports over the study period, 5,375,621 emergency transports were reported during the winter months (November through February). The overall cumulative relative risk (RR) at the first percentile vs. the minimum morbidity percentile was 1.24 (95 % CI = 1.15-1.34) for all causes, 1.50 (95 % CI = 1.30-1.74) for cardiovascular diseases, and 1.59 (95 % CI = 1.33-1.89) for respiratory diseases. There were differences in the temporal variations between extreme low temperature and respiratory disease morbidity. Spatial variation between prefectures was observed for all causes (Cochran Q test, p < 0.001; I ² = 34.0 %) and respiratory diseases (Cochran Q test, p = 0.026; I ² = 18.2 %); however, there was no significant spatial heterogeneity for cardiovascular diseases (Cochran Q test, p = 0.413; I ² = 2.0 %). Our findings indicated that there were differences in the spatiotemporal variations of extreme low temperatures for emergency transport during winter in Japan. Our findings highlight the importance of further investigating to identify social and environmental factors, which can be responsible for spatial heterogeneity between prefectures.

Effect of treatment modality on in-hospital outcome in patients with subarachnoid hemorrhage: a nationwide study in Japan (J-ASPECT Study)

OBJECTIVE Although heterogeneity in patient outcomes following subarachnoid hemorrhage (SAH) has been observed across different centers, the relative merits of clipping and coiling for SAH remain unknown. The authors sought to compare the patient outcomes between these therapeutic modalities using a large nationwide discharge database encompassing hospitals with different comprehensive stroke center (CSC) capabilities. METHODS They analyzed data from 5214 patients with SAH (clipping 3624, coiling 1590) who had been urgently hospitalized at 393 institutions in Japan in the period from April 2012 to March 2013. In-hospital mortality, modified Rankin Scale (mRS) score, cerebral infarction, complications, hospital length of stay, and medical costs were compared between the clipping and coiling groups after adjustment for patient-level and hospital-level characteristics by using mixed-model analysis. RESULTS Patients who had undergone coiling had significantly higher in-hospital mortality (12.4% vs 8.7%, OR 1.3) and a shorter median hospital stay (32.0 vs 37.0 days, p < 0.001) than those who had undergone clipping. The respective proportions of patients discharged with mRS scores of 3-6 (46.4% and 42.9%) and median medical costs (thousands US$, 35.7 and 36.7) were not significantly different between the groups. These results remained robust after further adjustment for CSC capabilities as a hospital-related covariate. CONCLUSIONS Despite the increasing use of coiling, clipping remains the mainstay treatment for SAH. Regardless of CSC capabilities, clipping was associated with reduced in-hospital mortality, similar unfavorable functional outcomes and medical costs, and a longer hospital stay as compared with coiling in 2012 in Japan. Further study is required to determine the influence of unmeasured confounders.

Out-of-hospital cardiac arrest attributable to sunshine: a nationwide, retrospective, observational study

Aims

To investigate the population attributable risk of out-of-hospital cardiac arrest (OHCA) from non-optimal sunshine duration and the relative contribution of daily sunshine hours.

Methods and Results

National registry data of all cases of OHCA occurred between 2005 and 2014 in the 47 Japanese prefectures were obtained. We examined the relationship between daily duration of sunshine and OHCA risk for each prefecture in Japan using a Poisson regression model combined with a distributed lag non-linear model, adjusting for confounding factors. The estimated associations for each prefecture were pooled at the nationwide level using a multivariate random-effects meta-analysis. A total of 658 742 cases of OHCA of presumed cardiac origin met our inclusion criteria. The minimum morbidity sunshine duration varied from the 21st percentile in Okayama to the 99th percentile in Hokkaido, Gifu, and Hyogo. Overall, 5.78% [95% empirical confidence interval (eCI): 3.57-7.16] of the OHCA cases were attributable to daily sunshine duration. The attributable fraction for short sunshine duration (below the minimum morbidity sunshine duration) was 4.18% (95% eCI: 2.64-5.38), whereas that for long sunshine duration (above the minimum morbidity sunshine duration) was 1.59% (95% eCI: 0.81-2.21).

Conclusions

Daily sunshine duration was responsible for OHCA burden, and a greater number of OHCA cases occurred in patients who were only exposed to sunshine for short periods of time each day. Our findings suggest that public health efforts to reduce OHCA burden should take sunshine level into account.

Spatiotemporal variation in heat-related out-of-hospital cardiac arrest during the summer in Japan

BACKGROUND

Although several studies have reported the impacts of extremely high temperature on cardiovascular diseases, few studies have investigated the spatiotemporal variation in the incidence of out-of-hospital cardiac arrest (OHCA) due to extremely high temperature in Japan.

METHODS

Daily OHCA data from 2005 to 2014 were acquired from all 47 prefectures of Japan. We used time-series Poisson regression analysis combined with a distributed lag non-linear model to assess the temporal variability in the effects of extremely high temperature on OHCA incidence in each prefecture, adjusted for time trends. Spatial variability in the relationships between extremely high temperature and OHCA between prefectures was estimated using a multivariate random-effects meta-analysis.

RESULTS

We analyzed 166,496 OHCA cases of presumed cardiac origin occurring during the summer (June to September) that met the inclusion criteria. The minimum morbidity percentile (MMP) was the 51st percentile of temperature during the summer in Japan. The overall cumulative relative risk at the 99th percentile vs. the MMP over lags 0-10days was 1.21 (95% CI: 1.12-1.31). There was also a strong low temperature effect during the summer periods. No substantial difference in spatial or temporal variability was observed over the study period.

CONCLUSIONS

Our study demonstrated spatiotemporal homogeneity in the risk of OHCA during periods of extremely high temperature between 2005 and 2014 in Japan. Our findings suggest that public health strategies for OHCA due to extremely high temperatures should be finely adjusted and should particularly account for the unchanging risk during the summer.

Abstract WMP98: A Nationwide Study of Non-traumatic Intracranial Hemorrhage in Patients Receiving Direct Oral Anticoagulant Therapy: J-Aspect Study

Background and purpose: The incidence of non-traumatic intracranial hemorrhage (ICH) during treatment with direct oral anticoagulants (DOACs) is lower than that during warfarin treatment. The characteristics of intracranial hemorrhage during DOAC therapy, however, remain unclear. Therefore, we performed a nationwide survey in Japan to examine the clinical characteristics and outcomes of DOAC-associated ICH using data obtained from the Japanese Diagnosis Procedure Combination (DPC)-based Payment System.

Methods: We analyzed the data of 1,567 patients with ICH (DOAC-associated ICH, 88; warfarin-associated ICH, 1,479) who were urgently hospitalized at 575 institutions across Japan from April 2010 to March 2013 for whom prescription data before admission were available.

Results: The annual number of patients with all anticoagulant (DOAC or warfarin)- associated ICH in each year from 2010 to 2013 was 226, 252, 426, and 663, representing 15.7%, 15.4%, 16.1%, and 16.1% of all ICH cases in the same period, respectively. There was an increase in the proportion of patients who presented with DOAC-associated ICH in all anticoagulant-associated ICH in each year from 2010 to 2013 (0%→0.4%→3.8%→10.7%). The proportion of patients with impaired consciousness (three-digit score on Japan Coma Scale) at admission (DOAC, 19.3%; Warfarin, 25.4%; P=0.20), in-hospital mortality within 7 days (DOAC, 11.4%; Warfarin, 19.5%; P=0.06), and mRS score of 5-6 at discharge (DOAC, 27.3%; Warfarin, 37.4%; P=0.06) were lower in the patients with DOAC-associated ICH. The rates of surgery for hematoma removal were significantly lower in the patients with DOAC-associated ICH (NOAC, 2.3%; Warfarin, 9.7%; P=0.019).

Conclusions: This is the largest nationwide study of DOAC-associated ICH in a real-world situation in Japan, revealing that the patients with DOAC-associated ICH had better clinical outcomes compared with warfarin-associated ICH, probably due to milder hemorrhage at admission.

Abstract TP290: Comparison of Risk-Adjusted 30-day Mortality Models by Claims Data in Acute Ischemic Stroke With vs Without Adjustment for Stroke Severity: J-ASPECT Study

Introduction: Reports on hospital-specific, risk-standardized outcomes using claims data on acute ischemic stroke are increasing. However, these reports sometimes fail to account for stroke severity.

Hypothesis: Hospital-specific, risk-adjusted mortality rating without accounting for stroke severity are altered after including initial severity for ischemic strokes.

Methods: The health insurance claims data known as the Japanese Diagnosis Procedure Combination/Per Diem Payment Systems between April 1, 2013 and May 31, 2014 was obtained from 332 certified training institutions in Japan. The hospital-specific, risk-adjusted 30-day mortality rate was calculated using a hierarchical logistic regression model. We developed two models, with and without initial levels of consciousness (LOC), and compared them to assess the impact of stroke severities on hospital-specific mortalities. The hospital-specific mortalities with and without LOC were ranked and groped into 3 categories (top 20%, middle 60%, and bottom 20%), and then compared across the two models. We used an integrated discrimination improvement (IDI) index to measure how the model with LOC reclassified patients compared with the model without LOC. Patients with deep comas were excluded from the analyses.

Results: We analyzed 64,569 acute ischemic stroke patients. Crude 30-day mortality was 3.9% , the mean age was 74.1±1.3 years, 41.2% were women, 70.8% had hypertension, 29.2% had diabetes mellitus, 79.9% had a Charlson comorbidity index score greater than 5, 3.7% had severe LOC (coma/semi-coma) and 8.1% had modestly impaired LOC. Among hospitals ranked in the top 20% of performers without LOC, 26.9% were ranked in the middle 60% when LOC was adjusted. Among the bottom 20% of performers without LOC, 21.2% were ranked in the middle 60% when LOC was adjusted. The hospital-specific, risk-adjusted 30-days mortality model with LOC had a significantly better IDI index score than the model without LOC (IDI, 0.09; P<0.001).

Conclusions: Adding the metric of stroke severity to a hospital-specific, risk-adjusted 30-day mortality model based on claims data was associated with model improvement and changes of mortality-based performance rankings.

Abstract WP309: Effects of Comprehensive Stroke Care Capabilities on Outcome of Carotid Endarterectomy and Carotid Artery Stenting (from the J-ASPECT Study [2013 to 2015])

Background: The effectiveness of comprehensive stroke center (CSC) capabilities on outcome of carotid endarterectomy (CEA) and carotid artery stenting (CAS) remains uncertain. We performed a nationwide study to examine whether CSC capabilities influenced in-hospital outcome of CEA and CAS.

Methods: We analyzed 12,943 carotid artery stenosis patients treated with CEA or CAS in 350 certified training hospitals in Japan. Data between April 1, 2013 and May 31, 2015 was obtained from Japanese Diagnosis Procedure Combination Database. Among the institutions that responded, outcome was assessed by in-hospital mortality, ischemic stroke and myocardial infarction. CSC capabilities were evaluated from the 749 certified training institutions in Japan, which responded to a questionnaire survey regarding CSC capabilities that queried the availability of personnel, diagnostic techniques, specific expertise, infrastructure, and educational components recommended for CSCs. Total CSC scores of the participating hospitals were classified into quartiles (Q1: 0-15, Q2: 16-17, Q3: 18-19, Q4: 20-24).

Results: The proportion of CEA and CAS were 5068 and 7875 (2013: 1685 and 2590, 2014: 1668 and 2564, 2015: 1715 and 2721). Between CEA and CAS, mortality rates were 0.24% and 0.75%, ischemic stroke were 8.41% and 7.56% and myocardial infarction were 0.76% and 0.17%. These outcomes had no differences among the years. There was tendency that mortality rates were lower with high total CSC scores in patients with CEA (Q1: 0.42%, Q2: 0.26%, Q3: 0.12%, Q4: 0%, P=0.16), but there were no differences with CAS (Q1: 1.0%, Q2: 0.74%, Q3: 0.63%, Q4: 0.83%, P=0.73). Ischemic stroke were significantly lower with high CSC scores in CEA (Q1: 9.76%, Q2: 10.77%, Q3: 9.14%, Q4: 6.59%, P<0.05) and CAS (Q1: 9.86%, Q2: 8.76%, Q3: 7.14%, Q4: 6.98%, P<0.05). Myocardial infarction had no correlation with CSC scores in CEA (Q1: 0.21%, Q2: 0.35%, Q3: 0%, Q4: 0.36%, P=0.37) and CAS (Q1: 0.3%, Q2: 0%, Q3: 0.31%, Q4: 0.16%, P=0.19).

Conclusion: It is reported using the data of Nationwide Inpatient Sample that operator volume was an important predictor of postprocedural outcomes in CAS. We demonstrated that CSC capabilities were associated with reduced in-hospital ischemic stroke in patients with CEA and CAS.

Abstract TP429: Association Between Perioperative Management and Outcome in Aged SAH Patients

Background and purpose: The outcomes of subarachnoid hemorrhage (SAH) in aged patients are more severe than those in non-aged patients. There are few reports about the relationship between the age and the effect of perioperative care for SAH patients. We performed a nationwide survey in Japan to determine the relationship between perioperative care and SAH outcomes in aged and non-aged patients.

Methods: We analyzed 17,343 subarachnoid hemorrhage (SAH) patients treated with clipping or coiling in 579 hospitals who participated in the J-ASPECT study. Data between 2010 and 2013 were obtained from the Japanese Diagnosis Procedure Combination Database. We stratified patients into two groups according to their age (aged group >75 y.o., n=3885; non-aged group < 75 y.o., n=13,458) and analyzed the association between perioperative care and poor outcome (modified Rankin Scale score 3-6 at the time of discharge). With respect to perioperative care, we evaluated time from onset to surgery (days), treatment (clipping or coiling), and drugs delivered after surgery (fasudil hydrochloride, ozagrel sodium, cilostazol, statin, EPA, edaravone).

Results: In the non-aged group, coiling (OR=0.84; P<0.01) and treatment with fasudil hydrochloride (OR=0.59; P<0.01), statin (OR=0.83; P<0.01), and EPA (OR=0.83; P<0.01) significantly improved the outcomes and cilostazol treatment tended to improve the outcomes (OR=0.91; P=0.07). In both groups, edaravone treatment was associated with poor outcome (aged group: OR=2.34, P<0.01; non-aged group: OR=2.33, P<0.01). Although no factor that could improve outcome in the aged group was identified, JCS scores less than 30, coiling (OR=0.80; P=0.03), and EPA treatment (OR=0.74; P=0.02) were statistically significant prognosis improvement factors.

Conclusion: Coiling and treatment with fasudil hydrochloride, statins, and EPA improved outcomes of non-aged patients. Although perioperative care did not improve the outcome of aged SAH patients, in cases of relatively mild SAH, perioperative care had the potential to improve the outcome.