Real World Data in Japan: Chapter II The Diagnosis Procedure Combination Database

Algorithms Identifying Patients With Acute Exacerbation of Interstitial Pneumonia and Acute Interstitial Lung Diseases Developed Using Japanese Administrative Data

BACKGROUND

We aimed to develop algorithms to identify patients with acute exacerbation of interstitial pneumonia and acute interstitial lung diseases using Japanese administrative data.

METHODS

This single-center validation study examined diagnostic algorithm accuracies. We included patients >18 years old with at least one claim that was a candidate for acute exacerbation of interstitial pneumonia, acute interstitial lung diseases, and pulmonary alveolar hemorrhage who were admitted to our hospital between January 2016 and December 2021. Diagnoses of these conditions were confirmed by at least two respiratory physicians through a chart review. The positive predictive value was calculated for the created algorithms.

RESULTS

Of the 1,109 hospitalizations analyzed, 285 and 243 were for acute exacerbation of interstitial pneumonia and acute interstitial lung diseases, respectively. As there were only five cases of pulmonary alveolar hemorrhage, we decided not to develop an algorithm for it. For acute exacerbation of interstitial pneumonia, acute interstitial lung diseases, and acute exacerbation of interstitial pneumonia or acute interstitial lung diseases, algorithms with high positive predictive value (0.82, 95% confidence interval: 0.76-0.86; 0.82, 0.74-0.88; and 0.89, 0.85-0.92, respectively) and algorithms with slightly inferior positive predictive value but more true positives (0.81, 0.75-0.85; 0.77, 0.71-0.83; and 0.85, 0.82-0.88, respectively) were developed.

CONCLUSION

We developed algorithms with high positive predictive value for identifying patients with acute exacerbation of interstitial pneumonia and acute interstitial lung diseases, useful for future database studies on such patients using Japanese administrative data.

Dynamic changes in patient admission and their disabilities in multiple sclerosis and neuromyelitis optica: A Japanese nationwide administrative data study

BACKGROUND

The real-world data evidences how establishment of neuromyelitis optica (NMO) disease concept and development disease modifying therapy affect the patients with multiple sclerosis (MS) and NMO are lacking. The aim of this study is to clarify the diachronic trend of the severity and admissions of patients with MS and NMO.

METHODS

We retrospectively investigated the trends in admissions, treatments, and disabilities in the patients with MS and NMO using the Japanese administrative data between 2012 and 2017.

RESULTS

We analyzed acute stage 9545 and 2035 admissions in each 6100 MS and 1555 NMO patients. The annual number of admission in MS significantly decreased in 6 years; however, those in NMO consistently increased. The patient proportion with lower disability was significantly increased in MS and NMO. These trends were especially observed in patients admitted to centralized hospitals with more active treatments, such as second-line disease modifying therapy for MS and plasmapheresis for NMO. Patients with NMO using DMT for MS diminished in 6 years.

CONCLUSION

A gradual improvement of disability in patients with MS and NMO was observed, probably due to advanced treatments, increased NMO awareness, and decreased misdiagnosis, which seems to be the key for better prognosis in MS and NMO.

Incidence, management, and prognostic impact of arrhythmias in patients with Takotsubo syndrome: a nationwide retrospective cohort study

AIMS

Arrhythmia is a major complication of Takotsubo syndrome (TTS). However, its incidence, management, and prognostic impact remain to be elucidated in a large cohort.

METHODS AND RESULTS

We retrospectively identified 16 713 patients hospitalized for TTS between July 2010 and March 2021 from the Japanese Diagnosis Procedure Combination database. Serious arrhythmias were defined as ventricular tachycardia/fibrillation (VT/VF), 2nd-/3rd-degree atrioventricular block (AVB), sick sinus syndrome (SSS), or unspecified arrhythmias requiring device treatment. Patient characteristics and outcomes were compared based on the occurrence of serious arrhythmias. The overall incidence proportion of serious arrhythmias was 6.2% (n = 1036; 449 VT/VF, 283 2nd-/3rd-degree AVB, 133 SSS, 55 multiple arrhythmias, 116 others), which remained stable over 11 years. The arrhythmia group was younger, more often male, and exhibited greater impairment in activities of daily living (ADLs) and consciousness than the non-arrhythmia group. Although crude in-hospital mortality was higher in the arrhythmia group (9.6% vs. 5.0%, P < 0.001), the significant association between arrhythmias and mortality disappeared after adjustment for confounders (odds ratio = 1.15, 95% confidence interval = 0.90-1.49). Meanwhile, age, sex, ADLs, consciousness level, and Charlson comorbidity index were significantly associated with mortality. In the arrhythmia group, 254 (24.5%) patients received pacemakers (18.4%) or defibrillators (6.1%), which were implanted at a median of 8 and 19 days after admission, respectively.

CONCLUSION

Arrhythmias are not uncommon in TTS. Patients' background characteristics, rather than arrhythmia itself, may be associated with in-hospital mortality. Given the reversibility of cardiac dysfunction in TTS, there may be unnecessary device implantations for arrhythmias occurring as sequelae to TTS, warranting further investigations.

Therapeutic interventions and the length of hospital stay for pediatric patients with COVID-19: a multicenter cohort study

The evidence for pediatric patients with COVID-19 was very limited, which was attributed to the small number of the cases as well as the rare incidence of severe pneumonia in this population. This retrospective cohort study aimed to identify the characteristics of pediatric patients with COVID-19 in the early period of the pandemic by analyzing Diagnosis Procedure Combination (DPC) data in Japan. This retrospective cohort analysis of Japanese multicenter research on COVID-19 using DPC data compared the outcomes and costs of treatment for pediatric patients with COVID-19. Of 4700 patients with COVID-19, 186 pediatric patients were included in this study. Among the included pediatric patients, 17 received therapeutic drugs specifically for COVID-19, while the remaining 169 pediatric patients received only symptomatic therapy. There were no significant differences in the length of hospital stay (9 vs. 8 days, p = 0.96), and medical cost (97,585 vs. 73,291 JPY) for the intervention and control groups, respectively by multiple regression analysis. This is the first epidemiological study to use DPC data to summarize the pathophysiology of pediatric patients in the early period of COVID-19 pandemic. There was no significant difference in length of hospital stay or medical cost by intervention.

Physical Rehabilitation and Post-Stroke Pneumonia: A Retrospective Observational Study Using the Japanese Diagnosis Procedure Combination Database

In this study, the relationship between the duration of physical rehabilitation and occurrence of pneumonia after ischemic stroke was examined. We included 426,508 patients aged ≥75 years with acute ischemic stroke. A multilevel logistic regression analysis nested at the hospital level was conducted to examine the association between the duration of physical rehabilitation and occurrence of pneumonia. The duration of physical rehabilitation refers to the hours of physical rehabilitation performed daily until the 7th day of hospitalization. In the multivariable analysis, the intensity of rehabilitation for durations of 20-39 min/day (adjusted odds ratio [aOR]: 0.78, 95% Confidence Interval [CI]: 0.75-0.81, p < 0.001), 40-59 min/day (aOR: 0.68, 95% CI: 0.66-0.71, p < 0.001), 60-79 min/day (aOR:0.56, 95% CI: 0.53-0.58, p < 0.001), and ≥80 min/day (aOR: 0.46, 95% CI: 0.44-0.48, p < 0.001) were significantly associated with a reduced incidence of pneumonia. In addition, the trend identified for duration of rehabilitation was significant (p < 0.001). The results of this study suggest the usefulness of high-duration physical rehabilitation for preventing pneumonia in older patients with ischemic stroke.

Association Between Intraoperative Landiolol Use and In-Hospital Mortality After Coronary Artery Bypass Grafting: A Nationwide Observational Study in Japan

BACKGROUND

Ischemic heart disease is a leading cause of death worldwide, and coronary artery bypass grafting (CABG) is a major treatment. Landiolol is an ultra-short-acting beta-antagonist known to prevent postoperative atrial fibrillation. However, the effectiveness of intraoperative landiolol on mortality remains unknown. This study aimed to evaluate the association between intraoperative landiolol use and the in-hospital mortality in patients undergoing CABG.

METHODS

To conduct this retrospective cohort study, we used data from the Japanese Diagnosis Procedure Combination inpatient database. All patients who underwent CABG during hospitalization between July 1, 2010, and March 31, 2020, were included. Patients who received intraoperative landiolol were defined as the landiolol group, whereas the other patients were defined as the control group. The primary outcome was in-hospital mortality. Propensity score matching was used to compare the landiolol and control groups.

RESULTS

In total, 118,506 patients were eligible for this study, including 25,219 (21%) in the landiolol group and 93,287 (79%) in the control group. One-to-one propensity score matching created 24,893 pairs. After propensity score matching, the in-hospital mortality was significantly lower in the landiolol group than that in the control group (3.7% vs 4.3%; odds ratio 0.85; 95% confidence interval 0.78 to 0.94; P = .010).

CONCLUSIONS

Intraoperative landiolol use was associated with decreased in-hospital mortality in patients undergoing CABG. Further randomized controlled trials are required to confirm these findings.

Noninvasive Positive Airway Pressure Management for Post-extubation Support in Preterm Infants: Observational Cohort Study with Overlap Weighting Analysis

BACKGROUND

Nasal continuous positive airway pressure (NCPAP), nasal intermittent positive pressure ventilation (NIPPV), and high-flow nasal cannula (HFNC) are often used after initial extubation in preterm infants. However, data regarding the choice between NCPAP/NIPPV and HFNC are limited. This study examined which therapy was more effective as post-extubation support.

METHODS

This is a retrospective, cohort study that used the Diagnosis Procedure Combination database in Japan, 2011-2021. Propensity score overlap weighting analyses were performed to compare the composite outcomes of in-hospital death and reintubation in preterm infants who received NCPAP/NIPPV and HFNC. We identified infants born at gestational age 22-36 weeks who were intubated within 1 day of birth. We included patients who underwent NCPAP/NIPPV or HFNC after initial extubation. Patients with airway obstruction or congenital airway abnormalities were excluded.

RESULTS

We identified 1,203 preterm infants treated with NCPAP/NIPPV (n = 525) or HFNC (n = 678). The median (interquartile range) gestational age at delivery was 30 (27-33) weeks, and birth weight was 1296 (884-1,802) g. Compared with the HFNC group, the NCPAP/NIPPV group had a significantly lower proportion of the composite outcome after the overlap weighting analysis (risk ratio, 0.62; 95% confidence interval, 0.47 to 0.83; p = 0.001). This significant difference was also observed in infants born at gestational age 22-31 weeks, whereas no significant difference was observed in infants born at gestational age 32-36 weeks.

CONCLUSIONS

NCPAP/NIPPV may be a superior post-extubation support than HFNC in preterm infants, especially in those born at gestational age of 22-31 weeks.

Endoscopic surgery versus craniotomy for spontaneous intracerebral hemorrhage in the late elderly patients

OBJECTIVES

To compare the prognosis of late elderly patients with spontaneous intracerebral hemorrhage (ICH) treated by endoscopic evacuation and craniotomy MATERIALS AND METHODS: Using the Diagnosis Procedure Combination database, we identified patients aged ≥ 75 years who underwent surgery for spontaneous ICH within 48 hours after admission between April 2014 and March 2018. Eligible patients were classified into two groups according to the type of surgery (endoscopic surgery and craniotomy). Propensity-score matching weight analysis was conducted to compare the good neurological outcome modified Rankin Scale (mRS) score (0-4) at discharge as the primary endpoint between the two groups. Secondary endpoints were postoperative meningitis, tracheostomy, reoperation within 3 days and total hospitalization costs.

RESULTS

Among the 5,396 eligible patients, endoscopic surgery and craniotomy were performed in 895 and 4,501 patients, respectively. In the propensity-score matching weight analysis, all covariates were well balanced. The proportions of patients with a good prognosis (mRS score at discharge: 0-4) did not significantly differ between the surgical procedures (42.1% vs. 42.8%, p = 0.828). The proportions of meningitis, tracheostomy and reoperation were not significantly different between the two groups. Hospitalization costs were significantly higher in the craniotomy group than in the endoscopic surgery group (25,536 vs. 29,603 US dollars, p = 0.012).

CONCLUSIONS

Inhospital outcomes did not differ between endoscopic and open surgeries for spontaneous ICH in the late-stage elderly patients aged ≥75 years. Hospitalization costs were significantly higher in the craniotomy group, suggesting that endoscopic surgery may be more acceptable.

Hospital volume and outcomes following bronchoscopy in patients with interstitial lung disease: A retrospective observational study using a national inpatient database in Japan

BACKGROUND

Interstitial lung diseases (ILDs) are a group of diffuse parenchymal lung disorders that cause inflammation and fibrosis in the interstitium of the lungs. Histopathological examination is pivotal to accurately diagnose the type of ILD, and bronchoscopy (BS) is often performed to collect lung tissue. This study aimed to determine the relationship between hospital volume and outcomes following BS in patients with ILD.

METHODS

Inpatient data on patients with ILD who underwent BS between July 1, 2010 and March 31, 2021 were extracted from the Japanese Diagnosis Procedure Combination database. The annual hospital volume of BS was categorized into four (very low- [≤15 cases/year], low- [16-29 cases/year], high- [30-54 cases/year], and very high- [≥55 cases/year] volume) groups. The primary outcome was all-cause 14-day mortality after BS. Multiple imputation methods followed by multivariable logistic regression analyses fitted with generalized estimating equations were used to estimate the association between hospital volume and 14-day mortality after BS.

RESULTS

A total of 89,454 patients with ILD from 1002 hospitals underwent BS. The all-cause mortality within 14 days after BS was 0.77%. An inverse trend was observed between mortality and hospital volume. Compared with the very low-hospital volume group, the very high-hospital volume group was significantly associated with a lower mortality (adjusted odds ratio = 0.63, 95% confidence interval: 0.48-0.85, p = 0.002).

CONCLUSIONS

Hospital volume was inversely associated with all-cause mortality within 14 days after BS for hospitalized patients with ILD.

Outcomes Following Laparoscopic Versus Open Surgery for Pediatric Intussusception: Analysis Using a National Inpatient Database in Japan

BACKGROUND

Laparoscopic surgery for pediatric intussusception has recently become more common as an alternative to open surgery. However, the differences in outcomes between laparoscopic and open surgery remain unclear. Thus, this study aimed to compare short-term surgical outcomes and recurrence rates between patients treated with laparoscopic and open surgery for pediatric intussusception.

METHODS

Patients aged <18 years who underwent laparoscopic (n = 192) and open (n = 416) surgery for intussusception between April 2016 and March 2021 were retrospectively identified using a Japanese nationwide inpatient database. Propensity-score overlap weighting analyses were conducted to compare the outcomes between the laparoscopic and open surgery groups. The outcomes included in-hospital morbidity, reoperation, readmission for intussusception, bowel resection, the diagnosis of Meckel's diverticulum, duration of anesthesia, postoperative length of hospital stay, and total hospitalization costs.

RESULTS

The laparoscopic surgery group was older, heavier, and had fewer congenital malformations and emergency admissions than the open surgery group did. Overlap weighting analyses showed no significant differences in in-hospital morbidity (odds ratio [95% confidence interval], 0.88 [0.35-2.23]), reoperation (1.88 [0.24-14.9]), readmission for intussusception within 30 days (0.80 [0.12-5.30]) and 1 year (0.90 [0.28-2.93]), bowel resection (0.69 [0.46-1.02]), the diagnosis of Meckel's diverticulum (0.97 [0.50-1.90]), duration of anesthesia (difference, 11 [-1-24] minutes), postoperative length of stay (difference, -1.9 [-4.2-0.4] days), or total hospitalization costs (difference, 612 [ -746-1970] US dollars) between the groups.

CONCLUSIONS

In this large nationwide cohort, no significant differences in outcomes were observed between laparoscopic and open surgery. Laparoscopic surgery is an acceptable treatment option for pediatric intussusception.

LEVELS OF EVIDENCE

Level III.

Effectiveness and safety of the co-administration of Yokukan-San (Japanese herbal medicine) with antipsychotics in hospitalized older patients with pneumonia

AIM

Behavioral and psychological symptoms and delirium frequently occur in hospitalized older patients with pneumonia and are associated with longer hospital stays. Yokukan-San (YKS, traditional Japanese [Kampo] medicine) and antipsychotics are often used to treat delirium and behavioral and psychological symptoms in Japan. Hence, this study aimed to assess the effectiveness and safety of the co-administration of YKS with atypical antipsychotics in older patients with pneumonia.

METHODS

We used the Japanese Diagnosis Procedure Combination inpatient database to retrospectively identify older patients (≥65 years) hospitalized for pneumonia who received antipsychotics within 3 days of hospitalization. The patients were divided into two groups: those who received atypical antipsychotics alone (control group) and those who received both atypical antipsychotics and YKS (YKS group). We compared length of hospital stay, in-hospital mortality, bone fractures, and administration of potassium products between the two groups using propensity score overlap weighting.

RESULT

We identified 4789 patients in the YKS group and 61 641 in the control group. After propensity score overlap weighting, length of hospital stay was statistically significantly shorter in the YKS group (percentage difference -3.0%; 95% confidence interval -5.8% to -0.3%). The proportion of patients who received potassium products was higher in the YKS group (odds ratio 1.34; 95% confidence interval 1.15-1.55). In-hospital death and bone fractures were not significantly different.

CONCLUSION

Co-administration of YKS with atypical antipsychotics could be a reasonable treatment option for hospitalized older patients with pneumonia and aggressive psychiatric symptoms. Geriatr Gerontol Int 2023; 23: 849-854.

Thrombotic risk of platinum combination chemotherapy with and without immune checkpoint inhibitors for advanced non-small cell lung cancer: a nationwide inpatient database study

OBJECTIVES

To determine the associated thromboembolism risk with adding immune checkpoint inhibitors (ICI) to platinum combination chemotherapy compared with platinum combination chemotherapy alone in patients with advanced non-small cell lung cancer.

MATERIALS AND METHODS

This study identified 75,807 patients with advanced non-small cell lung cancer from the Japanese Diagnosis Procedure Combination database who started platinum combination chemotherapy between July 2010 and March 2021. The incidence of venous thromboembolism (VTE), arterial thromboembolism (ATE), and all-cause mortality within 6 months after commencing platinum combination chemotherapy was compared between patients receiving chemotherapy with ICI (ICI group, n = 7,177) and without ICI (non-ICI group, n = 37,903). Survival time analysis was performed using the overlap weighting method with propensity scores to adjust for background factors. The subdistribution hazard ratio for developing thromboembolism was calculated using the Fine-Gray model with death as a competing risk. The hazard ratio for all-cause mortality was also calculated using the Cox proportional hazards model.

RESULTS

Overall, VTE and ATE occurred in 761 (1.0%) and 389 (0.51%) patients, respectively; mortality was 11.7%. Propensity score overlap weighting demonstrated that the subdistribution hazard ratio (95% confidence interval) for VTE and ATE in the ICI group was 1.27 (1.01-1.60) and 0.96 (0.67-1.36), respectively, compared with the non-ICI group. The mortality hazard ratio in the ICI group was 0.68 (0.62-0.74).

CONCLUSION

The addition of ICI to platinum combination therapy was associated with a higher risk of VTE compared with platinum combination therapy alone, while the risk of ATE might be comparable.

Risk factors for early mortality in elderly patients with unstable isolated C2 odontoid fracture treated with halo-vest or surgery

The aim of this study was to compare in-hospital mortality of three procedures -halo-vest immobilization, anterior spinal fixation (ASF), and posterior spinal fixation (PSF)- in the treatment of elderly patients with isolated C2 odontoid fracture. We extracted data for elderly patients who were admitted with C2 odontoid fracture and treated with at least one of the three procedures (halo-vest immobilization, ASF, or PSF) during hospitalization. We conducted a generalized propensity score-based matching weight analysis to compare in-hospital mortality among the three procedures. We further investigated independent risk factors for in-hospital death. The study involved 891 patients (halo-vest, n = 463; ASF, n = 74; and PSF, n = 354) with a mean age of 78 years. In-hospital death occurred in 45 (5.1%) patients. Treatment type was not significantly associated with in-hospital mortality. Male sex (odds ratio 2.98; 95% confidence interval 1.32-6.73; p = 0.009) and a Charlson comorbidity index of ≥ 3 (odds ratio 9.18; 95% confidence interval 3.25-25.92; p < 0.001) were independent risk factors for in-hospital mortality. In conclusion, treatment type was not significantly associated with in-hospital mortality in elderly patients with isolated C2 odontoid fracture. Halo-vest immobilization can help to avoid adverse events in patients with C2 odontoid fracture who are considered less suitable for surgical treatment.

Polymyxin B-immobilised fibre column treatment for acute exacerbation of idiopathic pulmonary fibrosis patients with mechanical ventilation: a nationwide observational study

BACKGROUND

The prognosis for acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is poor, and there is no established treatment. Hence, we aimed to investigate the effectiveness of a polymyxin B-immobilised fibre column (PMX) for the treatment of AE-IPF.

METHODS

Data were retrospectively collected from the Japanese Diagnosis Procedure Combination database from 1 July 2010 to 31 March 2018. We identified adult patients with idiopathic pulmonary fibrosis who received high-dose methylprednisolone (mPSL) therapy and mechanical ventilation upon admission. Eligible patients (n = 5616) were divided into those receiving PMX treatment combined with high-dose mPSL (PMX group, n = 199) and high-dose mPSL alone (mPSL alone group, n = 5417). To compare outcomes between the two groups, we applied a stabilised inverse probability of treatment weighting (IPTW) using propensity scores. The primary outcome was in-hospital mortality, and the secondary outcomes were 14- and 28-day mortality and length of hospital stay.

RESULTS

The in-hospital mortality rates of the PMX and mPSL alone groups were 79.9% and 76.4%, respectively. The results did not significantly differ between the two groups after performing a stabilised IPTW. The odds ratio of the PMX group compared with the mPSL alone group was 1.56 (95% confidence interval 0.80-3.06; p = 0.19). The 14- and 28-day mortality and length of hospital stay (secondary outcomes) also did not significantly differ between the two groups.

CONCLUSIONS

In AE-IPF patients using mechanical ventilation, the treatment outcome was not significantly better for PMX combined with high-dose mPSL than for high-dose mPSL alone.

Development and Validation of a Novel Method for Converting the Japan Coma Scale to Glasgow Coma Scale

BACKGROUND

The Japan Coma Scale (JCS) is the most frequently adopted method for evaluating level of consciousness in Japan. However, no validated method for converting the JCS to the Glasgow Coma Scale (GCS) exists. The aims of the present study were to develop and validate a method to convert the JCS to GCS.

METHODS

This is a multicenter retrospective analysis involving three emergency departments (EDs) in Japan. We included all adult patients who visited the ED between 2017 and 2020. The participating facilities were divided into two cohorts-one cohort to develop a table to convert the JCS to GCS (development cohort), and the other cohort to validate the conversion table (validation cohort). The conversion table of the JCS to GCS was developed based on the median values of the GCS. The outcome was the concordance rate between the JCS and GCS.

RESULTS

We identified 8,194 eligible patients. The development cohort included 7,373 patients and the validation cohort included 821 patients. In the validation cohort, the absolute and relative concordance rates were 80.3% (95% confidence interval, 77.4-82.9%) and 93.2% (95% confidence interval, 91.2-94.8%), respectively.

CONCLUSION

This study developed and validated a novel method for converting the JCS to GCS. Assuming the offset by a single category between the JCS and GCS is acceptable, the concordance rate was over 90% in the general adult patient population visiting the ED. The conversion method may assist researchers to convert JCS scores into GCS scores, which are more commonly recognized among global audiences.

Proportion of early extubation and short-term outcomes after esophagectomy: a retrospective cohort study

BACKGROUND

The proportion of early extubation after esophagectomy varies among hospitals; however, the impact on clinical outcomes is unclear. The aim of this retrospective study was to evaluate associations between the proportion of early extubation in hospitals and short-term outcomes after esophagectomy. Because there is no consensus regarding the optimal timing for extubation, the authors considered that hospitals' early extubation proportion reflects the hospital-level extubation strategy.

MATERIALS AND METHODS

Data of patients who underwent oncologic esophagectomy (July 2010-March 2019) were extracted from a Japanese nationwide inpatient database. The proportion of patients who underwent early extubation (extubation on the day of surgery) at each hospital was assessed and grouped by quartiles: very low- (<11%), low- (11-37%), medium- (38-83%), and high-proportion (≥84%) hospitals. The primary outcome was respiratory complications; secondary outcomes included reintubation, anastomotic leakage, other major complications, and hospitalization costs. Multivariable regression analyses were performed, adjusting for patient demographics, cancer treatments, and hospital characteristics. A restricted cubic spline analysis was also performed for the primary outcome.

RESULTS

Among 37 983 eligible patients across 545 hospitals, early extubation was performed in 17 931 (47%) patients. Early extubation proportions ranged from 0-100% across hospitals. Respiratory complications occurred in 10 270 patients (27%). Multivariable regression analyses showed that high- and medium-proportion hospitals were significantly associated with decreased respiratory complications [odds ratio, 0.46 (95% CI, 0.36-0.58) and 0.43 (0.31-0.60), respectively], reintubation, and hospitalization costs when compared with very low-proportion hospitals. The risk of anastomotic leakage and other major complications did not differ among groups. The restricted cubic spline analysis demonstrated a significant inverse dose-dependent association between the early extubation proportion and the risk of respiratory complications.

CONCLUSION

A higher proportion of early extubation in a hospital was associated with a lower occurrence of respiratory complications, highlighting a potential benefit of early extubation after esophagectomy.

Reduced Asthma Exacerbations in Adult Patients Treated With Bronchial Thermoplasty

BACKGROUND

Bronchial thermoplasty (BT) has been shown to be effective in randomized controlled trials of patients with severe asthma who failed to achieve disease control with high-dose inhaled corticosteroids combined with bronchodilators. However, the effectiveness of BT in real-world clinical settings, especially among the Asian population, has not been determined.

OBJECTIVE

To evaluate the effectiveness of BT using a nationwide database.

METHODS

Using the inpatient and outpatient data from the Japanese Diagnosis Procedure Combination database, we applied a self-controlled case series design to evaluate changes in the composite outcome of hospital admissions and emergency department visits, as well as systemic corticosteroid dose, between 1 year before and after BT. We also conducted subgroup analyses based on patients' profiles.

RESULTS

Among the 561 patients with asthma who underwent BT treatment between September 2014 and March 2020, 102 patients with at least 1 outcome were analyzed. Bronchial thermoplasty was significantly associated with an improvement in the composite outcome of hospital admission and emergency department visits (incidence rate ratio 0.53; 95% CI 0.44-0.64). Systemic corticosteroid use was reduced after BT sessions (1931.5 mg [1,341.2-3,725.3 mg] to 641.3 mg [134.2-1,691.1 mg] per person-year; P < .001). Although all groups showed a significant improvement in the composite outcome in the subgroup analyses, BT tended to be less effective among people older than 65 years and those with higher body mass index (>25 kg/m2).

CONCLUSIONS

The present study using real-world data suggests that BT may improve asthma control; however, the effectiveness of BT can vary depending on patient baseline profiles.

Effects of Milrinone on Neonates after Patent Ductus Arteriosus Ligation: A Retrospective Nationwide Database Study

INTRODUCTION

Milrinone is administered after patent ductus arteriosus (PDA) ligation to prevent and treat postoperative hemodynamic instability (i.e., postligation cardiac syndrome). We aimed to explore the effectiveness of milrinone on in-hospital outcomes in infants who underwent PDA ligation using a nationwide inpatient database in Japan.

METHODS

Using the Japanese Diagnosis Procedure Combination database, we identified patients who received milrinone after PDA ligation (n = 428) in neonatal intensive care units between July 2010 and March 2021 and those who did not (n = 3,392). We conducted a 1:4 propensity score-matched analysis with adjustment for background characteristics (e.g., gestational age, birth weight, comorbidities, preoperative treatments, and hospital background) to compare morbidities (bronchopulmonary dysplasia, intraventricular hemorrhage, necrotizing enterocolitis, and retinopathy of prematurity), mortality, total hospitalization costs, and other outcomes. For sensitivity analysis, we performed an overlap propensity score-weighted analysis.

RESULTS

In-hospital morbidity, bronchopulmonary dysplasia, intraventricular hemorrhage, and necrotizing enterocolitis occurred in 58%, 48%, 9.5%, and 7.1% of patients, respectively; the in-hospital mortality was 5.4%. After 1:4 propensity score matching, no significant difference was observed regarding mortality (7.1 vs. 5.7%), in-hospital morbidity (55 vs. 50%), bronchopulmonary dysplasia (44 vs. 41%), intraventricular hemorrhage (7.8 vs. 9.1%), necrotizing enterocolitis (8.5 vs. 8.9%), retinopathy of prematurity (21 vs. 22%), or total hospitalization costs (median: approximately 86,000 vs. 82,000 US dollars) between milrinone users (n = 425) and nonusers (n = 1,698). Sensitivity analyses yielded consistent results.

CONCLUSIONS

Milrinone use after PDA ligation was not associated with improved in-hospital outcomes, such as mortality and morbidity.

Systemic steroid therapy for pneumonic chronic obstructive pulmonary disease exacerbation: A retrospective cohort study

The effectiveness of systemic steroid therapy on mortality in patients with pneumonic chronic obstructive pulmonary disease (COPD) exacerbation is unclear. We evaluated the association between systemic steroid therapy and 30-day mortality after adjusting for known confounders, using data from the Health, Clinic, and Education Information Evaluation Institute in Japan, which longitudinally followed up patients in the same hospital. We selected patients aged ≥40 years admitted for pneumonic COPD exacerbation. The exclusion criteria were censoring within 24 h, comorbidity with other respiratory diseases, and daily steroid use. Systemic steroid therapy was defined as oral/parenteral steroid therapy initiated within two days of admission. The primary outcome was the 30-day mortality rate. To account for known confounders, each patient was assigned an inverse probability of treatment weighting. The outcome was evaluated using logistic regression. Among 3,662 patients showing pneumonic COPD exacerbation, 30-day mortality in the steroid therapy and non-steroid therapy groups was 27.6% (169/612) and 21.9% (668/3,050), respectively. Systemic steroid therapy indicated a slightly higher estimated probability of 30-day mortality (difference in the estimated probabilities, 2.65%; 95% confidence interval, -1.23 to 6.54%, p-value = 0.181). Systemic steroid therapy within two days of admission was associated with higher 30-day mortality rates in pneumonic COPD exacerbation. Further validation studies based on chart reviews will be needed to cope with residual confounders.

Impact of a financial incentive scheme for team-based palliative care in patients with heart failure in Japan: A nationwide database study

BACKGROUND

Palliative care provided to patients with heart failure (HF) are reported to be inadequate. Herein, we examined the impact of the recently introduced financial incentive scheme for team-based palliative care for patients with HF in acute care hospitals in Japan.

METHODS

Using a nationwide inpatient database, we identified patients aged ≥65 years with HF who had died between April 2015 and March 2021. Interrupted time-series analyses were used to compare practice patterns in end-of-life care (symptom management and invasive medical procedures within one week before death) before and after the financial incentive scheme issuance in April 2018.

RESULTS

Overall, 53,857 patients in 835 hospitals were eligible. The adoption of the financial incentive was 1.10 to 1.22% after the introduction. There were upward pre-trends in opioid use (+0.11% per month; 95% confidence interval [CI], 0.06 to 0.15) and antidepressant use (+0.06% per month; 95% CI, 0.04 to 0.09). Opioid use showed a downward slope change during the post-period (-0.07% change in trend; 95% CI, -0.13 to -0.01). Intensive care unit stay showed a downward pre-trend (-0.09% per month; 95% CI, -0.14 to -0.04) and upward slope changes during the post-period (+0.12% change in trend; 95% CI, 0.04 to 0.19). Invasive mechanical ventilation showed downward slope changes during the post-period (-0.11% change in trend; 95% CI, -0.18 to -0.04).

CONCLUSIONS

The financial incentive scheme for team-based palliative care was rarely adopted and not associated with changes in end-of-life care. Further multifaceted strategies to promote palliative care for HF are warranted.

Trends in Mechanical Circulatory Support Use and Outcomes of Patients With Cardiogenic Shock in Japan, 2010 to 2020 (from a Nationwide Inpatient Database Study)

Little is known about the impact of the downgrade of guideline recommendations for intra-aortic balloon pump (IABP) use and the approval of the Impella in Japan, where IABPs have been predominantly used. This study aimed to describe the annual trends in the mechanical circulatory support (MCS) use and outcomes in patients with cardiogenic shock (CS) requiring MCS. Using the Japanese Diagnosis Procedure Combination database from July 2010 to March 2021, we identified inpatients with CS requiring MCS. The patients were stratified into 3 groups: (1) IABP alone, (2) Impella alone, and (3) extracorporeal membrane oxygenation (ECMO), regardless of IABP or Impella use. The patient characteristics and outcomes were reported by the fiscal year. Of the 160,559 eligible patients, 117,599 (73.2%) used IABP alone, 1,465 (0.9%) Impella alone, and 41,495 (25.8%) ECMO. The prevalence of the use of an IABP alone significantly decreased from 80.5% in 2010 to 65.3% in 2020 (p for trend <0.001), whereas the prevalence of the use of an Impella alone significantly increased from 0.0% to 5.0% and ECMO from 19.5% to 29.6% (p for trend <0.001 for both). In-hospital mortality significantly increased from 29.3% in 2010 to 32.6% in 2020 in the overall patients with CS requiring MCS but significantly decreased in those requiring ECMO from 73.7% to 64.1% (p for trend <0.001 for both). In conclusion, there were significant annual changes in the patterns of MCS use and clinical outcomes in patients with CS requiring MCS.

Association Between Levels of Intensive Care and In-Hospital Mortality in Patients Hospitalized for Sepsis Stratified by Sequential Organ Failure Assessment Scores

OBJECTIVES

To assess the association between levels of intensive care and in-hospital mortality in patients hospitalized for sepsis, stratified by Sequential Organ Failure Assessment (SOFA) score at admission.

DESIGN

A nationwide, propensity score-matched, retrospective cohort study.

SETTING

A Japanese national inpatient database with data on 70-75% of all ICU and high-dependency care unit (HDU) beds in Japan.

PATIENTS

Adult patients hospitalized for sepsis with SOFA scores greater than or equal to 2 on their day of admission between April 1, 2018, and March 31, 2021, were recruited. Propensity score matching was performed to compare in-hospital mortality, and patients were stratified into 10 groups according to SOFA scores.

INTERVENTIONS

Two exposure and control groups according to treatment unit on day of admission: 1) ICU + HDU versus general ward and 2) ICU versus HDU.

MEASUREMENTS AND MAIN RESULTS

Of 97,070 patients, 19,770 (20.4%), 23,066 (23.8%), and 54,234 (55.9%) were treated in ICU, HDU, and general ward, respectively. After propensity score matching, the ICU + HDU group had significantly lower in-hospital mortality than the general ward group, among cohorts with SOFA scores greater than or equal to 6. There were no significant differences in in-hospital mortality among cohorts with SOFA scores 3-5. The ICU + HDU group had significantly higher in-hospital mortality than the general ward among cohorts with SOFA scores of 2. The ICU group had lower in-hospital mortality than the HDU group among cohorts with SOFA scores greater than or equal to 12. There were no significant differences in in-hospital mortality among cohorts with SOFA scores 5-11. The ICU group had significantly higher in-hospital mortality than the general ward group among cohorts with SOFA scores less than or equal to 4.

CONCLUSIONS

Patients hospitalized for sepsis with SOFA scores greater than or equal to 6 in the ICU or HDU had lower in-hospital mortality than those in the general ward, as did those with SOFA scores greater than or equal to 12 in the ICU versus HDU.

Effect modification of the association between temperature variability and hospitalization for cardiovascular disease by comorbid diabetes mellitus: A nationwide time-stratified case-crossover analysis

AIMS

We aimed to explore the association between short-term exposure to temperature variability (TV), and cardiovascular hospitalization stratified by the presence of comorbid diabetes.

METHODS

We collected data on nationwide hospitalization for cardiovascular diseases and daily weather conditions during 2011-2018 in Japan. TV was calculated as the standard deviation of daily minimum and maximum temperatures within 0-7 lag days. We applied a two-stage time-stratified case-crossover design to estimate the association between TV and cardiovascular hospitalization with and without comorbid diabetes, adjusting for temperature and relative humidity. Furthermore, specific cardiovascular disease causes, demographic characteristics, and seasons were used for stratification.

RESULTS

In 3,844,910 hospitalizations for cardiovascular disease, each 1 °C increase in TV was associated with a 0.44% (95% CI: 0.22%, 0.65%) increase in the risk of cardiovascular admission. We observed a 2.07% (95% CI: 1.16%, 2.99%) and 0.61% (95% CI: -0.02%, 1.23%) increase per 1 °C in risk of heart failure admission in individuals with and those without diabetes, respectively. The higher risk among individuals with diabetes was mostly consistent in the analyses stratified by age, sex, body mass index, smoking status, and season.

CONCLUSION

Comorbid diabetes may increase susceptibility to TV in relation to acute cardiovascular disease hospitalization.

Association between obesity and mortality in critically ill COVID-19 patients requiring invasive mechanical ventilation: a multicenter retrospective observational study

This study aimed to determine whether obesity and disease outcomes are associated in patients with critically-ill coronavirus disease 2019 (COVID-19) requiring invasive mechanical ventilation (IMV). This retrospective observational study using Japanese multicenter registry data included COVID-19 patients who required IMV and were discharged between January and September 2020. The patients were divided into the obese (body mass index [BMI] ≥ 25 kg/m²) and nonobese (BMI < 25 kg/m²) groups. Logistic regression models were used to analyze the association between obesity and disease outcomes. The primary outcome was in-hospital mortality; the secondary outcome was venovenous extracorporeal membrane oxygenation (VV-ECMO) implementation. Altogether, 477 patients were enrolled (obese, n = 235, median BMI, 28.2 kg/m²; nonobese, n = 242, median BMI, 22.4 kg/m²). Obesity was significantly associated with lower in-hospital mortality in the unadjusted logistic regression model (odds ratio 0.63; 95% confidence interval, 0.42-0.97; p = 0.033), but not with mortality in the adjusted logistic regression model using age, sex, and Charlson Comorbidity Index as covariates (p = 0.564). Obesity was not associated with VV-ECMO implementation in both unadjusted and adjusted models (unadjusted, p = 0.074; adjusted, p = 0.695). Obesity was not associated with outcomes in COVID-19 patients requiring IMV. Obesity may not be a risk factor for poor outcomes in these patients.

Validation studies of Japanese administrative health care data: A scoping review

PURPOSE

Large-scale administrative health care databases are increasingly being utilized for research. However, there has not been much literature that validated administrative data in Japan; a previous review identified six validation studies published between 2011 and 2017. We conducted a literature review of studies that assessed the validity of Japanese administrative health care data.

METHODS

We searched for studies published by March 2022 that compared individual-level administrative data with a reference standard from another data source, as well as studies that validated administrative data using other data within the same database. The eligible studies were also summarized based on characteristics which included data types, settings, reference standard used, numbers of patients, and conditions validated.

RESULTS

There were 36 eligible studies, including 29 that used external reference standard and seven that validated administrative data using other data within the same database. Chart review was the reference standard in 21 studies (range of the numbers of patients, 72-1674; 11 studies conducted in single institutions and nine studies in 2-5 institutions). Five studies used a disease registry as the reference standard. Diagnoses of cardiovascular diseases, cancer, and diabetes were frequently evaluated.

CONCLUSIONS

Validation studies are being conducted at an increasing rate in Japan, although most of them are small scale. Further large-scale comprehensive validation studies are necessary to effectively utilize the databases for research.

Treatment and outcome of hepatorenal syndrome in Japan: a retrospective cohort study using a national inpatient database

BACKGROUND

Hepatorenal syndrome (HRS) is a life-threatening complication of end-stage liver disease. This study aimed to clarify the status of HRS in Japan by analyzing the Japanese Diagnosis Procedure Combination database.

METHODS

Patients hospitalized for cirrhosis and HRS from July 2010 to March 2019 were sampled. They were divided into two groups according to their prognosis upon discharge: the transplant-free survival group and the death or liver transplantation group. The two groups' baseline patient characteristics and treatments were compared.

RESULTS

The mean age of the 1,412 participants was 67.3 years (standard deviation: 12.3 years), and 65.4% were male. The Child-Pugh grades was B and C in 18.8% and 81.2%, respectively. Hepatocellular carcinoma was present in 27.1% of the patients, and the proportion of spontaneous bacterial peritonitis was 2.3%. Albumin, noradrenaline, and dopamine were administered to 57.9%, 8.0%, and 14.9% of the patients, respectively; 7.0% of the patients underwent renal replacement therapy; and 5.0% were admitted to the intensive care unit. Intravenous antibiotics were administered to 30.8% of the patients. A total of 925 patients (65.5%) died or underwent liver transplantation. In addition to a higher proportion of patients with poor baseline liver function, the death or liver transplantation group included more males, patients with hepatocellular carcinoma, and those with spontaneous bacterial peritonitis.

CONCLUSIONS

HRS in Japan has a high mortality rate. Albumin was administered to over 50% of participants. Although noradrenaline is recommended in Japanese clinical guidelines, dopamine was more frequently used as a vasoconstrictor in clinical practice.

Relationship between institutional ventilated COVID-19 case volume and in-hospital death: A multicenter cohort study

BACKGROUND

The volume-outcome relationship in patients with severe Coronavirus disease 2019 (COVID-19) is unclear and is important for establishing a system for the medical care of severe COVID-19. This study aimed to evaluate the association between institutional case volume and outcomes in patients with ventilated COVID-19.

METHODS

We analyzed patients with severe COVID-19 on ventilatory control aged > 17 years who were enrolled in the J-RECOVER study, which is a retrospective multicenter observational study conducted between January 2020 and September 2020 in Japan. Based on the ventilated COVID-19 case volume, the higher one-third of institutions were defined as high-volume centers, the middle one-third as middle-volume centers, and the lower one-third as low-volume centers. The primary outcome measure was in-hospital mortality during hospitalization due to COVID-19. Multivariate logistic regression analysis for in-hospital mortality and ventilated COVID-19 case volume was performed after adjusting for multiple propensity scores and in-hospital variables. To estimate the multiple propensity score, we fitted a multinomial logistic regression model, which fell into one of the three groups based on patient demographics and prehospital factors.

RESULTS

We analyzed 561 patients who required ventilator management. In total, 159, 210, and 192 patients were admitted to low-volume (36 institutions, < 11 severe COVID-19 cases per institution during the study period), middle-volume (14 institutions, 11-25 severe cases per institution), and high-volume (5 institutions, > 25 severe cases per institution) centers, respectively. After adjustment for multiple propensity scores and in-hospital variables, admission to middle- and high-volume centers was not significantly associated with in-hospital death compared with admission to low-volume centers (adjusted odds ratio, 0.77 [95% confidence interval (CI): 0.46-1.29] and adjusted odds ratio, 0.76 [95% CI: 0.44-1.33], respectively).

CONCLUSIONS

There may be no significant relationship between institutional case volume and in-hospital mortality in patients with ventilated COVID-19.

Trends in Treatment Patterns and Outcomes of Patients With Pulmonary Embolism in Japan, 2010 to 2020: A Nationwide Inpatient Database Study

Background The impact of major changes in the treatment practice of pulmonary embolism (PE), such as limited indications for systemic thrombolysis and the introduction of direct oral anticoagulants, is not well documented. This study aimed to describe annual trends in the treatment patterns and outcomes in patients with PE. Methods and Results Using the Japanese Diagnosis Procedure Combination inpatient database from April 2010 to March 2021, we identified hospitalized patients with PE. Patients with high-risk PE were defined as those admitted for out-of-hospital cardiac arrest or who received cardiopulmonary resuscitation, extracorporeal membrane oxygenation, vasopressors, or invasive mechanical ventilation on the day of admission. The remaining patients were defined as patients with non-high-risk PE. The patient characteristics and outcomes were reported with fiscal year trend analyses. Of 88 966 eligible patients, 8116 (9.1%) had high-risk PE, and the remaining 80 850 (90.9%) had non-high-risk PE. Between 2010 and 2020, in patients with high-risk PE, the annual proportion of extracorporeal membrane oxygenation use significantly increased from 11.0% to 21.3%, whereas that of thrombolysis use significantly decreased from 22.5% to 15.5% (P for trend <0.001 for both). In-hospital mortality significantly decreased from 51.0% to 43.7% (P for trend=0.04). In patients with non-high-risk PE, the annual proportion of direct oral anticoagulant use increased from 0.0% to 38.3%, whereas that of thrombolysis use significantly decreased from 13.7% to 3.4% (P for trend <0.001 for both). In-hospital mortality significantly decreased from 7.9% to 5.4% (P for trend <0.001). Conclusions Substantial changes in the PE practice and outcomes occurred in patients with high-risk and non-high-risk PE.

Outcomes After Endoscopic Evacuation Versus Evacuation Using Craniotomy or Stereotactic Aspiration for Spontaneous Intracerebral Hemorrhage: Analysis Using a Japanese Nationwide Database

BACKGROUND

Various surgical methods are available for managing large intracerebral hemorrhage. This study compared the prognosis of patients with spontaneous intracerebral hemorrhage who underwent endoscopic evacuation, stereotactic aspiration, and craniotomy by using a nationwide inpatient database in Japan.

METHODS

Using the Diagnosis Procedure Combination database, we identified patients who underwent surgery for spontaneous intracerebral hemorrhage within 48 h after admission between April 2014 and March 2018. Eligible patients were classified into three groups according to the type of surgery (endoscopic surgery, stereotactic surgery, and craniotomy). Propensity score matching weight analysis was conducted to compare poor modified Rankin Scale score at discharge (severe disability or death) and hospitalization cost among the groups.

RESULTS

Among 17,860 eligible patients, craniotomy, stereotactic surgery, and endoscopic surgery were performed in 14,354, 474, and 3,032 patients, respectively. In the matching weight analysis, all covariates were well balanced. Compared with the endoscopic surgery group, the proportion of poor prognosis (modified Rankin Scale score at discharge of 5 or 6) was significantly higher in craniotomy groups (odds ratio 2.51, 95% confidence interval 1.11-5.68; p = 0.028). Subgroup analysis based on hemorrhage location and consciousness level at the time of admission showed no significant difference between the surgical procedures. Hospitalization costs were significantly higher in the craniotomy group than in the endoscopic surgery group (difference US $9,724, 95% confidence interval 2,169-17,259; p = 0.011).

CONCLUSIONS

Endoscopic surgery for spontaneous intracerebral hemorrhage was associated with improved prognosis compared with craniotomy at the hospital discharge. Future large-scale clinical trials are needed to evaluate the optimal surgical techniques for intracerebral hemorrhage.

Impact of Prophylactic Corticosteroid Use on In-hospital Mortality and Respiratory Failure After Esophagectomy for Esophageal Cancer: Nationwide Inpatient Data Study in Japan

OBJECTIVE

To assess the effect of preoperative prophylactic corticosteroid use on short-term outcomes after oncologic esophagectomy.

BACKGROUND

Previous studies have shown that prophylactic corticosteroid use may decrease the risk of respiratory failure following esophagectomy by attenuating the perioperative systemic inflammation response. However, its effectiveness has been controversial, and its impact on mortality remains unknown.

METHODS

Data of patients who underwent oncologic esophagectomy between July 2010 and March 2019 were extracted from a Japanese nationwide inpatient database. Stabilized inverse probability of treatment weighting, propensity score matching, and instrumental variable analyses were performed to investigate the associations between prophylactic corticosteroid use and short-term outcomes, such as in-hospital mortality and respiratory failure, adjusting for potential confounders.

RESULTS

Among 35,501 eligible patients, prophylactic corticosteroids were used in 22,620 (63.7%) patients. In-hospital mortality, respiratory failure, and severe respiratory failure occurred in 924 (2.6%), 5440 (15.3%), and 2861 (8.1%) patients, respectively. In stabilized inverse probability of treatment weighting analyses, corticosteroids were significantly associated with decreased in-hospital mortality [odds ratio (OR)=0.80; 95% confidence interval (CI): 0.69-0.93], respiratory failure (OR=0.84; 95% CI: 0.79-0.90), and severe respiratory failure (OR=0.87; 95% CI: 0.80-0.95). Corticosteroids were also associated with decreased postoperative length of stay and total hospitalization costs. The proportion of anastomotic leakage did not differ with the use of Propensity score matching and instrumental variable analysis demonstrated similar results.

CONCLUSIONS

Prophylactic corticosteroid use in oncologic esophagectomy was associated with lower in-hospital mortality as well as decreased respiratory failure and severe respiratory failure, suggesting a potential benefit for preoperative corticosteroid use in esophagectomy.

Association between ambient temperature and cause-specific cardiovascular disease admissions in Japan: A nationwide study

BACKGROUND

Substantial evidence suggests that non-optimal temperatures can increase the risk of cardiovascular disease (CVD) mortality and morbidity; however, limited studies have reported inconsistent results for hospital admissions depending on study locations, which also lack national-level investigations on cause-specific CVDs.

METHODS

We performed a two-stage meta-regression analysis to examine the short-term associations between temperature and acute CVD hospital admissions by specific categories [i.e., ischemic heart disease (IHD), heart failure (HF), and stroke] in 47 prefectures of Japan from 2011 to 2018. First, we estimated the prefecture-specific associations using a time-stratified case-crossover design with a distributed lag nonlinear model. We then used a multivariate meta-regression model to obtain national average associations.

RESULTS

During the study period, a total of 4,611,984 CVD admissions were reported. We found cold temperatures significantly increased the risk of total CVD admissions and cause-specific categories. Compared with the minimum hospitalization temperature (MHT) at the 98^th percentile of temperature (29.9 °C), the cumulative relative risks (RRs) for cold (5^th percentile, 1.7 °C) and heat (99^th percentile, 30.5 °C) on total CVD were 1.226 [95% confidence interval (CI): 1.195, 1.258] and 1.000 (95% CI: 0.998, 1.002), respectively. The RR for cold on HF [RR = 1.571 (95% CI: 1.487, 1.660)] was higher than those of IHD [RR = 1.119 (95% CI: 1.040, 1.204)] and stroke [RR = 1.107 (95% CI: 1.062, 1.155)], comparing to their cause-specific MHTs. We also observed that extreme heat increased the risk of HF with RR of 1.030 (95% CI: 1.007, 1.054). Subgroup analysis showed that the age group ≥85 years was more vulnerable to these non-optimal temperature risks.

CONCLUSIONS

This study indicated that cold and heat exposure could increase the risk of hospital admissions for CVD, varying depending on the cause-specific categories, which may provide new evidence to reduce the burden of CVD.

All-Cause Readmission or Potentially Avoidable Readmission: Which Is More Predictable Using Frailty, Comorbidities, and ADL?

Background and Objectives

Readmission-related health care reforms have shifted their focus from all-cause readmissions (ACR) to potentially avoidable readmissions (PAR). However, little is known about the utility of analytic tools from administrative data in predicting PAR. This study determined whether 30-day ACR or 30-day PAR is more predictable using tools that assess frailty, comorbidities, and activities of daily living (ADL) from administrative data.

Research Design and Methods

This retrospective cohort study was conducted at a large general acute care hospital in Tokyo, Japan. We analyzed patients aged ≥70 years who had been admitted to and discharged from the subject hospital between July 2016 and February 2021. Using administrative data, we assessed each patient's Hospital Frailty Risk Score, Charlson Comorbidity Index, and Barthel Index on admission. To determine the influence of each tool on readmission predictions, we constructed logistic regression models with different combinations of independent variables for predicting unplanned ACR and PAR within 30 days of discharge.

Results

Among 16 313 study patients, 4.1% experienced 30-day ACR and 1.8% experienced 30-day PAR. The full model (including sex, age, annual household income, frailty, comorbidities, and ADL as independent variables) for 30-day PAR showed better discrimination (C-statistic: 0.79, 95% confidence interval: 0.77-0.82) than the full model for 30-day ACR (0.73, 0.71-0.75). The other prediction models for 30-day PAR also had consistently better discrimination than their corresponding models for 30-day ACR.

Discussion and Implications

PAR is more predictable than ACR when using tools that assess frailty, comorbidities, and ADL from administrative data. Our PAR prediction model may contribute to the accurate identification of at-risk patients in clinical settings who would benefit from transitional care interventions.

Prevalence of preoperative opioid usage and its impact on postoperative outcomes: a retrospective cohort study

PURPOSE

Preoperative opioid treatment increases postoperative adverse events. This study was aimed to analyze preoperative opioid prevalence in countries with low opioid consumption. Additionally, the effect of low opioid usage on postoperative outcomes was also investigated.

METHODS

We conducted this single center retrospective cohort analysis in a Japanese university-affiliated hospital to investigate opioid usage and its impact on the duration of postoperative hospitalization and in-hospital mortality. Adult patients who underwent general anesthesia between 2015 and 2020 were included. We extracted the patients' characteristics, surgical information and postoperative outcomes. Subgroup analysis to address opioid dose effect was performed in high and low dose opioid subgroups.

RESULTS

Among 20,306 inpatients, 535 (2.63%) patients used opioids preoperatively. Tramadol was the most frequently used opioid. The median morphine equivalent (MME) dose was 15 mg/day. Median duration of hospitalization was 18 and 9 days in the opioid and non-opioid groups, and in-hospital mortality was 2.06% and 0.42%. Multivariable regression analysis demonstrated that preoperative opioid use was associated with a longer duration of hospitalization and in-hospital mortality. Subgroup analysis demonstrated longer durations of hospitalization in both high (> 30 mg/day MME) and low (≤ 30 mg/day MME) dose opioid groups, while higher in-hospital mortality was seen only in the high dose opioid group.

CONCLUSIONS

Preoperative opioid usage was one-tenth of the United States average. Despite its low prevalence and small dosage, preoperative opioid usage was associated with poor postoperative outcomes. Dedicated perioperative interventions to prevent opioid-associated adverse events should be developed even in countries with low opioid consumption.

Impact of sodium-glucose cotransporter-2 inhibitors on the risk of hip fracture in older patients in Japan using a nationwide administrative claims database: A matched case-control study

AIM

Some clinical trials have shown that sodium-glucose cotransporter-2 (SGLT2) inhibitors are associated with fracture risk. However, this notion remains controversial. This study aimed to evaluate hip fracture risk after the use of SGLT2 inhibitors while controlling for factors that may affect fracture risk. Furthermore, hip fracture risk is evaluated in relation to the SGLT2 inhibitors component and its concomitant use with other antidiabetic agents.

METHODS

Using large-scale real-world data, this case-control study investigated hospitalized patients between January 2018 and December 2020. Patients were aged 65-89 years and had been prescribed with SGLT2 inhibitors at least twice. Patients with hip fracture (cases) and those without (controls) were identified via 1:3 matching according to sex, age (±3 years), hospital size classification, and number of concomitant antidiabetic agents. Exposure to SGLT2 inhibitors of the cases and controls was compared with the use of multivariate conditional logistic regression.

RESULTS

After matching, 396 cases and 1081 controls were identified. The adjusted odds ratio for patients receiving treatment with SGLT2 inhibitors was 0.83 (95% confidence interval: 0.55-1.26), indicating no increase in hip fracture risk. Additionally, no increased risk was observed with respect to SGLT2 inhibitors by component or concomitant use with other antidiabetic agents.

CONCLUSION

Our study showed that SGLT2 inhibitors do not increase hip fractures in older patients. However, because the risk assessment of SGLT2 inhibitors by component and their concomitant use with other antidiabetic agents is based on a limited number of patients, it is important to interpret the results with caution. Geriatr Gerontol Int 2023; ••: ••-••.

Evaluation of Plasmapheresis vs Immunoglobulin as First Treatment After Ineffective Systemic Corticosteroid Therapy for Patients With Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis

Importance

Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) are severe cutaneous adverse reactions, and patients with SJS/TEN frequently require intensive care. However, there is limited evidence on the clinical outcomes of immunomodulating therapy, including plasmapheresis and intravenous immunoglobulin (IVIG) in patients with SJS/TEN.

Objective

To compare clinical outcomes of patients with SJS/TEN who were treated with plasmapheresis first vs IVIG first after ineffective systemic corticosteroid therapy.

Design, Setting, and Participants

This retrospective cohort study used data from a national administrative claims database in Japan that included more than 1200 hospitals and was conducted from July 2010 to March 2019. Inpatients with SJS/TEN who received plasmapheresis and/or IVIG therapy after initiation of at least 1000 mg/d of methylprednisolone equivalent systemic corticosteroid therapy within 3 days of hospitalization were included. Data were analyzed from October 2020 to May 2021.

Exposures

Patients who received IVIG or plasmapheresis therapy within 5 days after initiation of systemic corticosteroid therapy were included in the IVIG- and plasmapheresis-first groups, respectively.

Main Outcomes and Measures

In-hospital mortality, length of hospital stay, and medical costs.

Results

Of 1215 patients with SJS/TEN who had received at least 1000 mg/d of methylprednisolone equivalent within 3 days of hospitalization, 53 and 213 patients (mean [SD] age, 56.7 [20.2] years; 152 [57.1%] women) were included in the plasmapheresis- and IVIG-first groups, respectively. Propensity-score overlap weighting showed no significant difference in inpatient mortality rates between the plasmapheresis- and IVIG-first groups (18.3% vs 19.5%; odds ratio, 0.93; 95% CI, 0.38-2.23; P = .86). Compared with the IVIG-first group, the plasmapheresis-first group had a longer hospital stay (45.3 vs 32.8 days; difference, 12.5 days; 95% CI, 0.4-24.5 d; P = .04) and higher medical costs (US $34 262 vs $23 054; difference, US $11 207; 95% CI, $2789-$19 626; P = .009).

Conclusions and Relevance

This nationwide retrospective cohort study found no significant benefit to administering plasmapheresis therapy first instead of IVIG first after ineffective systemic corticosteroid treatment in patients with SJS/TEN. However, medical costs and length of hospital stay were greater for the plasmapheresis-first group.

Association between the Use of Suvorexant and Hip Fracture in Older Adults in Japan Using a Nationwide Administrative Claims Database: A Matched Case-Control Study

BACKGROUND AND OBJECTIVE

The use of benzodiazepines and nonbenzodiazepines increases the risk for hip fracture, but the effect of suvorexant, an orexin receptor antagonist, is not clear. The objective of this study was to investigate the association between suvorexant use and hip fractures in older adults.

METHODS

A case-control study was conducted using real-world data (RWD) from Medical Data Vision Co., Ltd. with patients hospitalized between January 2019 and December 2020. Patients were aged 65-84 years and had been prescribed suvorexant at least once. Patients with hip fracture (cases) and those without (controls) were identified by matching up to 1:4 for sex, age (± 2 years), and hospital size category. Suvorexant exposure was identified the day before hospitalization. Hip fracture risk associated with suvorexant was presented as adjusted odds ratios (aOR) with 95% confidence intervals (CI) using conditional logistic regression analysis.

RESULTS

Matching identified 389 cases and 1509 controls. The risk of hip fracture was not increased in patients treated with suvorexant [aOR: 0.86, 95% confidence interval (CI) 0.61-1.20]. Additionally, concomitant use of suvorexant with other hypnotics did not increase the risk. Benzodiazepines (1.01, 0.46-2.22), nonbenzodiazepines (1.16, 0.57-2.34), and melatonin (1.80, 0.82-3.94) were combined with suvorexant. The risk was increased for the use of benzodiazepine without suvorexant (1.88, 1.10-3.21).

CONCLUSIONS

Using RWD in Japanese older adults, we showed that sleep therapy with suvorexant was not associated with an increased risk of hip fracture. The results provide evidence-based drug safety information for the selection of hypnotics for sleep disorders, which increase with age.

Effectiveness of medical fee revisions for psychotropic polypharmacy in patients with mood disorders in Japan: An interrupted time-series analysis using a nationwide inpatient database

BACKGROUND

This study aimed to evaluate the effects of medical fee revisions aimed to reduce psychotropic polypharmacy in Japan on the proportion of psychotropic polypharmacy in discharge prescriptions for patients with major depressive disorder (MDD) or bipolar disorder (BD) using a nationwide inpatient database.

METHODS

In this retrospective cohort study, we used the Diagnosis Procedure Combination database to identify patients with MDD or BD discharged between April 2012 and March 2021. We targeted medical fee revisions in October 2014, April 2016, and April 2018. The major outcome was the monthly proportion of psychotropic polypharmacy in prescription at discharge using the criteria following the April 2018 revision (antidepressants ≥3, antipsychotics ≥3, anxiolytics ≥3, hypnotics ≥3, or sum of anxiolytics and hypnotics ≥4). We performed interrupted time series analyses to evaluate the changes in level and trend between pre- and post-revisions.

RESULTS

We identified 63,289 and 33,780 patients with MDD and BD respectively in the entire study period. In both the patient groups, there were significant decreases in the proportion of psychotropic polypharmacy at revision in October 2014, and no significant trend and level change at revision were observed in April 2016 and April 2018, with a few exceptions.

CONCLUSIONS

The medical fee revisions aimed to reduce psychotropic polypharmacy in Japan might have had a limited impact on discharge prescriptions for patients with MDD and BD.

Institutional Variance in Mortality after Percutaneous Coronary Intervention for Acute Myocardial Infarction in Korea, Japan, and Taiwan

BACKGROUND

Although there have been studies that compared outcomes of patients with acute myocardial infarction (AMI) across countries, little focus has been placed on institutional variance of outcomes. The aim of the present study was to compare institutional variance in mortality following percutaneous coronary intervention (PCI) for AMI and factors explaining this variance across different health systems.

METHODS

Data on inpatients who underwent PCI for AMI in 2016 were obtained from the National Health Insurance Data Sharing Service in Korea, the Diagnosis Procedure Combination (DPC) Study Group Database in Japan, and the National Health Insurance Research Database (NHIRD) in Taiwan. Multilevel analyses with inpatient mortality as the outcome and the hierarchical structure of patients nested within hospitals were conducted, adjusting for common patient-level and hospital-level variables. We compared the intraclass correlation coefficient (ICC) and the proportion of variance explained by hospital-level characteristics across the three health systems.

RESULTS

There were 17 351 patients from 160 Korean hospitals, 29 804 patients from 660 Japanese hospitals, and 10 863 patients from 104 Taiwanese hospitals included in the analysis. Inpatient mortality rates were 6.3%, 7.3%, and 6.0% in Korea, Japan, and Taiwan, respectively. After adjusting for patient and hospital characteristics, Taiwan had the lowest variation in mortality (ICC, 1.8%), followed by Korea (2.2%) and then Japan (4.5%). The measured hospital characteristics explained 38%, 19%, and 9% of the institutional variance in Korea, Taiwan, and Japan, respectively.

CONCLUSION

Korea, Japan, and Taiwan had similarly uniform outcomes across hospitals for patients undergoing PCI for AMI. However, Japan had a relatively large institutional variance in mortality and a lower proportion of variation explainable by hospital characteristics, compared with Korea and Taiwan.

Impact of Body Mass Index on Major Complications, Multiple Complications, In-hospital Mortality, and Failure to Rescue After Esophagectomy for Esophageal Cancer: A Nationwide Inpatient Database Study in Japan

OBJECTIVE

To examine the association of BMI with mortality and related outcomes after oncologic esophagectomy.

SUMMARY BACKGROUND DATA

Previous studies showed that high BMI was a risk factor for anastomotic leakage and low BMI was a risk factor for respiratory complications after esophagectomy. However, the association between BMI and in-hospital mortality after oncologic esophagectomy remains unclear.

METHODS

Data for patients who underwent esophagectomy for esophageal cancer between July 2010 and March 2019 were extracted from a Japanese nationwide inpatient database. Multivariate regression analyses and restricted cubic spline analyses were used to investigate the associations between BMI and short-term outcomes, adjusting for potential confounders.

RESULTS

Among 39,406 eligible patients, in-hospital mortality, major complications, and multiple complications (≥2 major complications) occurred in 1069 (2.7%), 14,824 (37.6%), and 3621 (9.2%), respectively. Compared with normal weight (18.5-22.9 kg/m 2 ), severe underweight (<16.0 kg/m 2 ), mild/moderate underweight (16.0-18.4 kg/m 2 ), and obese (≥27.5 kg/m 2 )were significantly associated with higher in-hospital mortality [odds ratio 2.20 (95% confidence interval 1.65-2.94), 1.25 (1.01-1.49), and 1.48 (1.05-2.09), respectively]. BMI showed U-shaped dose-response associations with mortality, major complications, and multiple complications. BMI also showed a reverse J-shaped association with failure to rescue (death after major complications).

CONCLUSIONS

Both high BMI and low BMI were associated with mortality, major complications and multiple complications after esophagectomy for esophageal cancer. Patients with low BMI were more likely to die once a major complication occurred. The present results can assist with risk stratification in patients undergoing oncologic esophagectomy.

Weight loss during neoadjuvant therapy and short-term outcomes after esophagectomy: a retrospective cohort study

BACKGROUND

Neoadjuvant therapy (NAT) has become common worldwide for resectable advanced esophageal cancer and frequently involves weight loss. Although failure to rescue (death after major complications) is known as an emerging surgical quality measure, little is known about the impact of weight loss during NAT on failure to rescue. This retrospective study aimed to investigate the association of weight loss during NAT and short-term outcomes, including failure to rescue after esophagectomy.

MATERIALS AND METHODS

Patients who underwent esophagectomy after NAT between July 2010 and March 2019 were identified from a Japanese nationwide inpatient database. Based on quartiles of percent weight change during NAT, patients were grouped into four categories of gain, stable, small loss, and loss (>4.5%). The primary outcomes were failure to rescue and in-hospital mortality. The secondary outcomes were major complications, respiratory complications, anastomotic leakage, and total hospitalization costs. Multivariable regression analyses were used to compare outcomes between the groups, adjusting for potential confounders, including baseline BMI.

RESULTS

Among 15 159 eligible patients, in-hospital mortality and failure to rescue occurred in 302 (2.0%) and 302/5698 (5.3%) patients, respectively. Weight loss (>4.5%) compared to gain was associated with increased failure to rescue and in-hospital mortality [odds ratios 1.55 (95% CI: 1.10-2.20) and 1.53 (1.10-2.12), respectively]. Weight loss was also associated with increased total hospitalizations costs, but not with major complications, respiratory complications, and anastomotic leakage. In subgroup analyses, regardless of baseline BMI, weight loss (>4.8% in nonunderweight or >3.1% in underweight) was a risk factor for failure to rescue and in-hospital mortality.

CONCLUSION

Weight loss during NAT was associated with failure to rescue and in-hospital mortality after esophagectomy, independent of baseline BMI. This emphasizes the importance of weight loss measurement during NAT to assess the risk for a subsequent esophagectomy.

Amputation After Endovascular Therapy With and Without Intravascular Ultrasound Guidance: A Nationwide Propensity Score-Matched Study

BACKGROUND

Intravascular ultrasound (IVUS) provides precise intravascular information during endovascular therapy (EVT). However, the clinical efficacy of IVUS in patients who undergo EVT remains unknown. The present study aimed to determine whether the use of IVUS-guided EVT is associated with better clinical outcomes in a real-world setting.

METHODS

Using the Japanese Diagnosis Procedure Combination administrative inpatient database from April 2014 to March 2019, we identified patients diagnosed with atherosclerosis of arteries of extremities and underwent EVT (percutaneous endovascular transluminal angioplasty and thrombectomy for extremities or percutaneous endovascular removal). Propensity score matching analysis was performed to compare outcomes between the patients who underwent IVUS on the same day as the first EVT intervention (IVUS group) and the others (non-IVUS group). The primary outcome was major and minor amputation for extremities within 12 months of the first EVT procedure. Secondary outcomes were bypass surgery, stent grafting, reintervention, all-cause death, readmission, and total hospitalization costs within 12 months of the first EVT procedure.

RESULTS

Among 85 649 eligible patients, 50 925 (59.5%) were IVUS group. After propensity score matching, the IVUS group had significantly lower incidence of 12-month amputation compared with the non-IVUS group (6.9% in the IVUS group versus 9.3% in the non-IVUS group; hazard ratio, 0.80 [95% CI, 0.72-0.89]). Compared with the non-IVUS group, the IVUS group showed a lower risk of bypass surgery and stent grafting and decreased total hospitalization costs, while a higher risk of reintervention and readmission. No significant differences in all-cause death were found between the 2 groups.

CONCLUSIONS

In this retrospective study, IVUS-guided EVT was associated with a lower amputation risk than non-IVUS-guided EVT. Our findings should be interpreted carefully because of the limitations of an observational study using administrative data. Further studies are warranted to confirm whether IVUS-guided EVT leads to decreased amputations.

Trend in the Numbers of Hospitalized Patients With Varicella, Herpes Zoster, and Ischemic Stroke in Japanese Individuals <20 Years of Age Before and After Implementation of Universal Varicella Vaccination

Several studies have shown an association between varicella-zoster virus infection and ischemic stroke. We analyzed the trends in the numbers of patients with varicella, herpes zoster and ischemic stroke before and after the universal vaccination program using a Japanese database of hospitalized patients. The number of patients with varicella decreased but those of herpes zoster and ischemic stroke did not change.

Prognostic factors among patients with Shiga toxin-producing Escherichia coli hemolytic uremic syndrome: A retrospective cohort study using a nationwide inpatient database in Japan

INTRODUCTION

Shiga toxin-producing Escherichia coli (STEC) causes hemorrhagic colitis and hemolytic uremic syndrome (STEC-HUS). Understanding its prognostic factors is essential for immediate interventions. We examined early-phase unfavorable prognostic factors among patients with STEC-HUS using a nationwide database.

MATERIAL AND METHODS

This is a retrospective cohort study to analyze practice patterns and identify prognostic factors among patients with STEC-HUS. We used the Diagnosis Procedure Combination Database, which includes approximately half of the acute-care hospitalized patients in Japan. We enrolled patients who were hospitalized for STEC-HUS from July 2010 to March 2020. The composite unfavorable outcome included in-hospital death, mechanical ventilation, dialysis, and rehabilitation at discharge. Unfavorable prognostic factors were assessed using a multivariable logistic regression model.

RESULTS

We included 615 patients with STEC-HUS (median age, 7 years). Of them, 30 (4.9%) patients had acute encephalopathy and 24 (3.9%) died within 3 months of admission. Unfavorable composite outcome was observed in 124 (20.2%) patients. Significant unfavorable prognostic factors were age of 18 years or older, methylprednisolone pulse therapy, antiepileptic drug administration, and respiratory support within 2 days of admission.

DISCUSSION

Patients requiring early steroid pulse therapy, antiepileptic drugs, and respiratory support were considered to be in poor general condition; such patients should receive aggressive intervention to avoid worse outcomes.

Treatments and outcomes of adult parapharyngeal and retropharyngeal abscess: 1882 cases from a Japanese nationwide database

PURPOSE

Although parapharyngeal and retropharyngeal abscesses are potentially fatal deep neck abscesses, there is limited evidence for the treatment courses for adult patients with these abscesses. We aimed to describe the practice patterns and clinical outcomes of adult patients undergoing an emergency surgery for parapharyngeal or retropharyngeal abscesses using a nationwide database.

MATERIALS AND METHODS

We identified patients aged ≥18 years who underwent emergency surgery for parapharyngeal (para group, n = 1148) or retropharyngeal (retro group, n = 734) abscesses from July 2010 to March 2020, using a nationwide inpatient database. We performed between-group comparisons of the baseline characteristics, treatment course, and outcomes.

RESULTS

Compared with the retro group, the para group was more likely to be older (median, 66 vs. 60 years; P < 0.001) and have several comorbidities, such as diabetes (21 % vs 16 %; P = 0.010) and epiglottitis (33 % vs. 26 %; P = 0.002), except for peritonsillar abscess (14 % vs. 22 %; P < 0.001) and tonsillitis (2.1 % vs. 13 %; P < 0.001). Regarding intravenous drugs administered within 2 days of admission, approximately half of the patients received steroids, non-antipseudomonal penicillins, and lincomycins. The para group received more comprehensive treatments, such as tracheostomy, intensive care unit admissions, and swallowing rehabilitation, within total hospitalization than the retro group. Moreover, it demonstrated higher in-hospital mortality (2.7 % vs. 1.1 %; P = 0.017) and morbidity (16 % vs. 9.7 %; P < 0.001), and longer length of hospitalization than the retro group.

CONCLUSION

The current nationwide study provided an overview of the characteristics, treatments, and outcomes for patients who underwent an emergency surgery for parapharyngeal or retropharyngeal abscess.

Current status of real-world big data research in the cardiovascular field in Japan

Real-world data (RWD) are observational data obtained by collecting, structuring, and accumulating patient information among the medical big data. RWD are derived from a variety of patient medical care and health information outside of conventional research data, and include electronic health records, claims data, registry data of disease, drug and device, health check-up data, and more recently, patient information data from wearable devices. They are currently being utilized in various forms for optimal medical care and real-world evidence (RWE) is constructed through a process of hypothesis generation and verification based on the RWD research. Together with classic clinical research and pragmatic trials, RWE shapes the learning healthcare system and contributes to the improvement of medical care. In the cardiovascular medical care of the current super-aged society, the need for a variety of RWE and the research is increasing, since the guidelines established over time and the medical care based on it cannot necessarily be the best in accordance with the current medical situation. In this review, we focus on the RWD and RWE studies in the cardiovascular medical field and outlines their current status in Japan. Furthermore, we discuss the potential for extending the studies and issues related to the use of medical big data and RWD.

Validity of diagnoses of respiratory diseases recorded in a Japanese administrative database

BACKGROUND

Validating the information recorded in administrative databases is essential. However, no study has comprehensively validated the accuracy of Japanese Diagnosis Procedure Combination (DPC) data on various respiratory diseases. Therefore, this study aimed to evaluate the validity of diagnoses of respiratory diseases in the DPC database.

METHODS

We conducted chart reviews of 400 patients hospitalized in the departments of respiratory medicine in two acute-care hospitals in Tokyo, between April 1, 2019 and March 31, 2021, and used them as reference standards. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of DPC data on 25 respiratory diseases were determined.

RESULTS

Sensitivity ranged from 22.2% (aspiration pneumonia) to 100% (chronic eosinophilic pneumonia and malignant pleural mesothelioma) and was <50% for eight diseases, while specificity was >90% for all diseases. PPV ranged from 40.0% (aspiration pneumonia) to 100% (coronavirus disease 2019, bronchiectasis, chronic eosinophilic pneumonia, pulmonary hypertension, squamous cell carcinoma, small cell carcinoma, lung cancer of other histological types, and malignant pleural mesothelioma) and was >80% for 16 diseases. Except for chronic obstructive pulmonary disease (82.9%) and interstitial pneumonia (other than idiopathic pulmonary fibrosis) (85.4%), NPV was >90% for all diseases. These validity indices were similar in both hospitals.

CONCLUSIONS

The validity of diagnoses of respiratory diseases in the DPC database was high in general, thereby providing an important basis for future studies.

Database analysis of hypersensitivity pneumonitis in Japan

BACKGROUND

Three epidemiological small-scale studies on hypersensitivity pneumonitis (HP) have been performed in Japan to date. Herein, we aimed to clarify the clinical characteristics of various types of HP diseases using a large nationwide database in Japan.

METHODS

We used the Japanese Diagnostic Procedure Combination database that includes data from 1,031 participant hospitals. Patients with HP from 2011 to 2017 were identified using International Classification of Diseases 10th Revision codes. We analyzed patient characteristics, the yearly transition of the number of HP cases, rate per one million hospitalizations, geographical distribution, seasonality, and risk factors for in-hospital mortality.

RESULTS

In total, 3,634 patients with HP were identified, including summer-type HP (SHP) (n = 490), bird fancier's lung (BFL) (n = 199), ventilation pneumonitis (n = 106), farmer's lung (n = 48), and unspecified HP (n = 2761). The length of hospital stay was significantly longer in patients with BFL (19 days) than in patients with SHP (15 days). SHP was more prevalent in the southwestern region of Japan, and hospitalization occurred mainly in summer (37.8%) and fall (37.3%). Ventilation pneumonitis was predominant in winter (28.6%) and spring (38.7%). In-hospital mortality was significantly associated with old age (p < 0.001), low body mass index (p = 0.016), severe dyspnea (p < 0.001), and BFL diagnosis on admission (p = 0.031).

CONCLUSIONS

This study revealed the clinical characteristics of SHP and BFL, including the frequency of causative antigens, geographical distribution, seasonality, and risk factors for mortality, which may help in diagnosing HP and identifying causative antigens.

Dementia and acute care of ischemic stroke in Japan: A retrospective observational study using the Japanese Diagnosis Procedure Combination database

AIM

This study aimed to determine the impact of dementia on the implementation of intravenous thrombolysis and early rehabilitation as acute care for patients with acute ischemic stroke in Japan.

METHODS

This retrospective observational study used the Japanese Diagnosis Procedure Combination database. Patients aged ≥75 years with acute ischemic stroke (ICD-10 code: I63) were enrolled (n = 464 710). In this study, dementia was identified using the ICD-10 codes (F00, F01, F02, F03, G30, and G31) for comorbidity. A mixed-effects logistic regression analysis nested at the hospital level was conducted to examine the impact of dementia on the implementation of intravenous thrombolysis and early rehabilitation.

RESULTS

Overall, 57 905 patients with ischemic stroke had dementia. The group with dementia was less likely to receive intravenous thrombolysis (5.2% vs. 6.9%) and more likely to undergo early rehabilitation than the group without dementia (76.1% vs. 73.0%). In the mixed-effects logistic regression analysis, dementia was significantly associated with a lower probability of undergoing intravenous thrombolysis (adjusted odds ratio: 0.79, 95% confidence interval: 0.76-0.82, P < 0.001) and a higher probability of early rehabilitation (adjusted odds ratio: 1.06, 95% confidence interval: 1.04-1.09, P < 0.001).

CONCLUSIONS

We found that while dementia was associated with fewer opportunities for aggressive treatment, such as intravenous thrombolysis, it was also associated with increased opportunities to receive rehabilitation. It is necessary to examine the reasons why patients with dementia do not receive aggressive treatment and to establish a system that allows older adults with and without dementia to receive equal access to medical care. Geriatr Gerontol Int 2023; ••: ••-••.

Effectiveness of systemic thrombolysis on clinical outcomes in high-risk pulmonary embolism patients with venoarterial extracorporeal membrane oxygenation: a nationwide inpatient database study

BACKGROUND

Current guidelines recommend systemic thrombolysis as the first-line reperfusion treatment for patients with high-risk pulmonary embolism (PE) who present with cardiogenic shock but do not require venoarterial extracorporeal membrane oxygenation (VA-ECMO). However, little is known about the optimal reperfusion treatment in high-risk PE patients requiring VA-ECMO. We aimed to evaluate whether systemic thrombolysis improved high-risk PE patients' outcomes who received VA-ECMO.

METHODS

This was a retrospective cohort study using the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2021. We identified patients who were diagnosed with PE and received VA-ECMO on the day of admission. Patients who received systemic thrombolysis with monteplase or urokinase within two days of initiating VA-ECMO were defined as the thrombolysis group and the remaining patients as the control group. The primary outcome was in-hospital mortality and secondary outcomes were favorable neurological outcomes, length of hospital stay, VA-ECMO duration, total hospitalization cost, major bleeding, and blood transfusion volume. Propensity-score inverse probability of treatment weighting (IPTW) was performed to compare the outcomes between the groups.

RESULTS

Of 1220 eligible patients, 432 (35%) received systemic thrombolysis within two days of initiating VA-ECMO. Among the unweighted cohort, patients in the thrombolysis group were less likely to have poor consciousness at admission, out-of-hospital cardiac arrest, and left heart catheterization. After IPTW, the patient characteristics were well-balanced between the two groups The crude in-hospital mortality was 52% in the thrombolysis group and 61% in the control group. After IPTW, in-hospital mortality did not differ significantly between the two groups (risk difference: - 3.0%, 95% confidence interval: - 9.6% to 3.5%). There were also no significant differences in the secondary outcomes. Sensitivity analyses showed a significant difference in major bleeding between the monteplase and control groups (risk difference: 6.9%, 95% confidence interval: 1.7% to 12.1%), excluding patients who received urokinase. There were no significant differences in the other sensitivity and subgroup analyses except for the total hospitalization cost.

CONCLUSIONS

Systemic thrombolysis was not associated with reduced in-hospital mortality or increased major bleeding in the high-risk PE patients receiving VA-ECMO. However, systemic thrombolysis with monteplase was associated with increased major bleeding.