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

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.

Prescribed daily-dose-based metrics of oral antibiotic use for hospitalized children in Japan

Objective

Defined daily-dose (DDD)-based metrics are frequently used to measure antibiotic consumption. However, they are unsuitable for the pediatric population because they are defined using the maintenance dose for 70-kg adults. Moreover, children have large body weight variations. We assessed the prescribed daily dose (PDD) and PDD-based metrics of oral antibiotics for children to develop an alternative to DDD-based metrics in Japan.

Design

We performed observational study using data from the Japanese administrative claims database between April 2018 and March 2019.

Methods

Of 453,001 patients (aged 1 month-15 years), 564,326 admissions to 1,159 hospitals were included. We showed the median PDD (mg/day and mg/kg/day) and PDD-based metrics for 8 antibiotics for each age category (1 month to <1 year old and 1-6, 7-12, and 13-15 years old). We also assessed the relationship between PDD-based metrics and days of therapy (DOT)-based metrics using a scatter plot and correlation.

Results

In total, 86,389 patients (19.1%) were prescribed oral antibiotics; amoxicillin, macrolides, and third-generation cephalosporins were the most common. The PDD (mg/day) for each antibiotic increased with age to 7-12 years old, when an adult dose was reached. The PDD (mg/kg/day) decreased with age to 13-15 years old, due to increasing body weight. The relationship between PDD per 1,000 patient days and DOT per 1,000 patient days differed depending on the antibiotic.

Conclusions

PDD-based metrics stratified by age could characterize antibiotic consumption, even with body-weight variations. Therefore, PDD-based metrics, in addition to DOT-based metrics, are helpful benchmarks for antibiotic use in children.

Association Between Systemic Corticosteroid Use and Mortality in Patients with Epiglottitis

OBJECTIVES

To clarify whether treatment with systemic corticosteroids at a certain dose was associated with better outcomes in patients with epiglottitis requiring airway management (tracheotomy or airway intubation).

METHODS

This was a retrospective cohort study on patients hospitalized for epiglottitis requiring airway management from a nationwide inpatient database (between July 2010 and March 2019). Patients treated with systemic corticosteroids equivalent to methylprednisolone ≥40 mg/d within 2 days of admission and patients who were not treated with corticosteroids within 2 days of admission were compared after inverse probability of treatment weighting using covariate balancing propensity score. The primary outcome was all-cause 30-day in-hospital mortality, and secondary outcomes included all-cause 7-day in-hospital mortality, length of hospital stay, and total medical cost.

RESULTS

There were 1986 and 1771 patients in the corticosteroid and control groups, respectively. A total of 72 of 3757 (1.9%) patients died within 30 days of admission, including 17 of 1986 (0.9%) patients in the corticosteroid group and 55 of 1771 (3.1%) in the control group (weighted odds ratio, 0.28 [95% confidence interval, 0.11-0.70]; weighted risk difference, -2.2% [-3.2% to -1.3%]). Treatment with corticosteroids was associated with lower total medical costs (weighted median, $6,187 vs. $6,587; weighted difference, $-1,123 [-2,238 to -8]) but not all-cause 7-day in-hospital mortality (weighted odds ratio, 0.63 [0.22-1.82]; weighted risk difference, -0.3% [-0.9 to 0.2]) and length of hospital stay (weighted median, 13 vs. 13 days; weighted difference, -0.2 days [-2.1 to 1.8]).

CONCLUSIONS

Systemic corticosteroids may be beneficial to patients with epiglottitis requiring airway management.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:344-349, 2023.

Clinical course and outcomes of pemphigus vulgaris and foliaceus: A retrospective study using a nationwide database in Japan

Pemphigus is a life-threatening autoimmune blistering disease. Patient characteristics, treatment courses, and outcomes remain unclear owing to its rarity. To describe the background, treatment, and outcomes of pemphigus, we identified 2598 patients with pemphigus vulgaris and 1186 patients with pemphigus foliaceus from a nationwide inpatient database in Japan. Patients with pemphigus vulgaris were younger (62 vs 72 years, P < 0.001), had fewer comorbidities, and were more likely to be admitted to high-volume hospitals (38% vs 30%, P < 0.001) than those with pemphigus foliaceus. Patients with pemphigus vulgaris had undergone more aggressive treatment, including steroid pulse therapy, intravenous immunoglobulin, or plasmapheresis, compared with those with pemphigus foliaceus (48% vs 42%, P = 0.001); specifically, in patients aged <70 years, the pemphigus vulgaris group was more likely to undergo aggressive treatment than the pemphigus foliaceus group (52% vs 45%), whereas there was no significant difference in patients aged ≥70 years (40% vs 40%). Immunosuppressive agents (30% vs 26%, P = 0.015) and analgesics, including opioids (45% vs 36%, P < 0.001), were used more frequently, whereas topical corticosteroids were used less frequently (32% vs 48%, P < 0.001) in patients with pemphigus vulgaris compared with those with pemphigus foliaceus. In-hospital mortality was lower in patients with pemphigus vulgaris than in those with pemphigus foliaceus (2.2% vs 4.0%, P = 0.002); in the comparison stratified by age, the mortality was equivalent among the two groups (0.6% in patients aged <70 years and 6.1% in those aged ≥70 years). Overall, patients with pemphigus vulgaris had a 10-day longer hospitalization period and higher hospitalization costs than those with pemphigus foliaceus. Our findings provide useful information for understanding the current trends in the management of pemphigus in Japan.

Oral Antibiotics and Organ Space Infection after Appendectomy and Intravenous Antibiotics Therapy for Complicated Appendicitis in Children

BACKGROUND

 There is little consensus regarding management after appendectomy for complicated appendicitis in children. Recent literature suggests that patients may be safely discharged without oral antibiotics after adequate intravenous antibiotics therapy. We conducted a nationwide retrospective cohort study comparing the proportion of postoperative organ space infection between patients discharged with and without oral antibiotics after appendectomy followed by intravenous antibiotics therapy for complicated appendicitis.

METHODS

 Using the Diagnosis Procedure Combination database, we identified patients between 3 and 18 years of age who had undergone appendectomy for complicated appendicitis between July 2010 and March 2018. Propensity score-matched analyses were performed to compare outcomes between the groups with and without oral antibiotics. The primary outcome was readmission due to organ space infection within 60 days of discharge and the secondary outcome was 60-day readmission due to any reason. Additionally, we conducted a stabilized inversed probability of treatment weighting analysis as a sensitivity analysis.

RESULTS

 We identified 13,100 eligible patients who had received oral antibiotics (n = 3,501) and who had not received oral antibiotics (n = 9,599). Propensity score matching created 2,769 pairs. Readmissions due to organ space infection were 3.4% and 5.2% in the nonusers and users of oral antibiotics, respectively (p = 0.007). The oral antibiotics users also had a significantly higher proportion of readmission due to any reason than the nonusers (5.5 vs. 7.4%, p = 0.004). The sensitivity analyses demonstrated consistent results.

CONCLUSION

 Among children who had undergone appendectomy for complicated appendicitis, oral antibiotics following discharge after adequate intravenous antibiotics therapy may increase organ space infection.

Short-term surgical outcomes of laparoscopic and open surgery for rectal cancer: A nationwide retrospective analysis

INTRODUCTION

Laparoscopy for treatment of rectal cancer is widely used in clinical practice. However, the safety and advantages of laparoscopy over open surgery at the national level remain unclear. We compared the short-term outcomes of laparoscopy and open surgery for rectal cancer.

METHODS

Using a Japanese nationwide inpatient database, this study analyzed data on patients who underwent rectal resection between July 2010 and March 2018. We performed propensity score matching analyses to compare in-hospital mortality, morbidities, blood transfusion, diverting stomas, anastomotic leakages, duration of anesthesia, postoperative length of stay, and readmission within 30 days between the laparoscopy and open surgery groups.

RESULTS

Among 99 137 eligible patients, propensity score matching generated 29 717 pairs. Laparoscopy was associated with lower in-hospital mortality (0.4% vs 0.6%, P = .006), overall morbidities (28.7% vs 33.2%, P < .001), and blood transfusion rate (11.5% vs 22.9%, P < .001); shorter postoperative duration of stay (16 days vs 18 days, P < .001); and longer duration of anesthesia (390 vs 310 minutes, P < .001). Grade C anastomotic leakage was not different between the groups.

CONCLUSION

With respect to in-hospital mortality, morbidities, blood transfusion, postoperative length of hospitalization, and readmission within 30 days, laparoscopy is advantageous over open surgery in the treatment of rectal cancer.

Comparison of bleeding complications after pediatric kidney biopsy between intravenous sedation and general anesthesia: a nationwide cohort study

BACKGROUND

An increasing number of studies are evaluating the safety of intravenous sedation compared with that of general anesthesia; however, data on bleeding complications after pediatric percutaneous renal biopsy performed under intravenous sedation or general anesthesia are lacking. We aimed to examine differences in bleeding complications between intravenous sedation and general anesthesia in pediatric patients.

METHODS

Data of pediatric patients aged ≤ 15 years undergoing percutaneous kidney biopsy for kidney disease between July 2007 and March 2019 were retrieved from a national inpatient database in Japan. We examined differences in bleeding complications after renal biopsy performed under intravenous sedation, defined by the absence of the record of general anesthesia with intubation but by the presence of intravenous sedation during biopsy, and general anesthesia, defined by the presence of the record of general anesthesia with intubation during biopsy, among pediatric patients admitted for percutaneous renal biopsy. We performed binomial regression using overlap weights based on propensity scores for patients receiving intravenous sedation. Analyses stratified by age or sex, a sensitivity analysis using generalized estimating equations considering cluster effects by hospital among a propensity score-matched cohort, and another sensitivity analysis using the instrumental variable method were performed to confirm the robustness of the results.

RESULTS

We identified 6,560 biopsies performed in 5,999 children aged 1-15 years from 328 hospitals and 178 events. Only three severe complications and no death were observed. No significant difference in the proportion of bleeding complications was observed between procedures performed under intravenous sedation and those performed under general anesthesia (unadjusted proportions, 2.8% and 2.3%; adjusted proportions, 2.5% and 2.2%), with an unadjusted relative risk of 1.21 (95% confidence interval, 0.80-1.81) and adjusted relative risk of 1.13 (95% confidence interval, 0.74-1.73). Both age- and sex-stratified analyses yielded similar results. The analysis using generalized estimating equation and the instrumental variable method showed relative risks of 0.95 (95% confidence interval, 0.48-1.88) and 1.18 (95% confidence interval, 0.74-1.89), respectively.

CONCLUSION

This retrospective cohort study using a national database revealed that the risk of biopsy-related bleeding was comparable between intravenous sedation and general anesthesia during pediatric percutaneous kidney biopsy, suggesting that intravenous sedation alone and general anesthesia may have a similar bleeding risk in pediatric percutaneous kidney biopsies.

Early postoperative non-steroidal anti-inflammatory drugs and anastomotic leakage after oesophagectomy

BACKGROUND

Previous studies have suggested that postoperative non-steroidal anti-inflammatory drug (NSAID) use may increase the risk of anastomotic leakage after colorectal surgery. However, the association between NSAIDs and anastomotic leakage after oesophagectomy is unclear. The aim of this retrospective study was to assess the effect of early postoperative NSAID use on anastomotic leakage after oesophagectomy.

METHODS

The Data of patients who underwent oesophagectomy for cancer between July 2010 and March 2019 were extracted from a Japanese nationwide inpatient database. Stabilized inverse probability of treatment weighting (IPTW), propensity score matching, and instrumental variable analyses were performed to investigate the association between NSAID use in the early postoperative period (defined as the day of and the day after surgery) and short-term outcomes, adjusting for potential confounders. The primary outcome was anastomotic leakage. The secondary outcomes were acute kidney injury, gastrointestinal bleeding, and mortality.

RESULTS

Among 39 418 eligible patients, early postoperative NSAIDs were used by 16 211 individuals (41 per cent). Anastomotic leakage occurred in 5729 patients (15 per cent). In stabilized IPTW analyses, NSAIDs were not associated with anastomotic leakage (odds ratio 1.04, 95 per cent c.i. 0.97 to 1.10). The proportions of acute kidney injury and gastrointestinal bleeding, as well as 30-day mortality and in-hospital mortality, did not differ according to NSAID use. Propensity score matching and instrumental variable analyses demonstrated similar results.

CONCLUSION

Early postoperative NSAID use was not associated with anastomotic leakage or other complications in patients who underwent oesophagectomy.

Association of Preoperative Rehabilitation With Postoperative Length of Hospital Stay for Elderly Lung Cancer Patients

This study aimed to evaluate the effect of preoperative rehabilitation on postoperative hospital stay in elderly lung cancer patients following lung resection. This was a retrospective observational study using the Japanese Diagnosis Procedure Combination database. Data of patients diagnosed between April 2016 and March 2020 were collected. Patients were identified using the International Statistical Classification of Disease and Related Health Problems Version 10-10 codes, C34.0-C34.3 and C34.8. Multilevel linear regression analysis was performed to evaluate the effect of preoperative rehabilitation on the length of hospital stay. A total of 9,393 patients were included in the study. Univariate analysis showed that preoperative rehabilitation was significantly associated with postoperative length of hospital stay (coefficient: -1.61; 95% confidence interval: -2.42, -0.81; P <0.001). In addition, multivariate analysis showed preoperative rehabilitation to be associated with a significant decrease in postoperative length of hospital stay (coefficient=-1.38; 95% confidence interval: -2.19, -0.58; P =0.001). Preoperative rehabilitation may shorten length of hospital stay in elderly patients with lung cancer.

Prednisolone versus cyclosporine as initial treatment for Kawasaki disease

BACKGROUND

Several studies have demonstrated the efficacy of prednisolone and cyclosporine as initial combination treatments for the prevention of coronary artery abnormalities (CAA) in patients with Kawasaki disease. However, whether prednisolone or cyclosporine results in superior clinical outcomes is unknown. Thus, this study aimed to compare the outcomes of these two treatments.

METHODS

Using the Japanese Diagnosis Procedure Combination database, we identified patients with Kawasaki disease who had received prednisolone or cyclosporine in addition to initial intravenous immunoglobulin treatment between April 2014 and March 2021. The primary outcome was the proportion of CAA; secondary outcomes included intravenous immunoglobulin resistance, medical costs, and length of hospital stay. Propensity score matching was conducted to compare outcomes between the two groups.

RESULTS

We identified 6288 patients with Kawasaki disease who had received prednisolone (n = 6147) or cyclosporine (n = 141) as an initial treatment in combination with intravenous immunoglobulin. Four-to-one propensity score-matched analysis demonstrated no significant difference in the proportion of CAA (0.7% vs. 2.8%; p = 0.098), intravenous immunoglobulin resistance, or medical costs between the treatment groups. The length of hospital stay was significantly longer in the prednisolone group (14 vs. 11 days, p < 0.001).

CONCLUSIONS

Prednisolone and cyclosporine used in the initial combination treatment for Kawasaki disease showed similar clinical outcomes regarding the risk of CAA, intravenous immunoglobulin resistance, and medical costs, whereas the length of hospital stay was longer in the prednisolone group than in the cyclosporine group.

The Relationship Between Preoperative Frailty Risk as Assessed by the Hospital Frailty Risk Score and the Outcome at Discharge in Coronary Artery Bypass Grafting (CABG) Patients: A Retrospective Observational Study Using the Diagnosis Procedure Combination Database

The relationship between the Hospital Frailty Risk Score (HFRS)-based frailty risk and outcomes after coronary artery bypass grafting (CABG) is yet unclear. The objective of this study was to investigate the relationship between preoperative frailty risk as assessed by the HFRS and postoperative outcomes in patients undergoing CABG. This observational study used the diagnosis procedure combination (DPC) system in Japan (2014-2017). In total, 35,015 adults aged ≥ 65 years and diagnosed with angina pectoris and acute myocardial infarction who had undergone CABG were enrolled. We investigated the association between the HFRS-based frailty risk and the home discharge rate, as well as the prevalence of complications. Multilevel logistic regression analysis revealed that having an HFRS ≥ 5 was a determinant of lower home discharge rate (odds ratio [OR] 0.60, 95% confidence interval [CI] 0.49-0.74, P <0.01), aspiration pneumonia (OR 2.25, 95%CI 1.27-3.96, P <0.01) and disuse syndrome (OR 1.90, 95%CI 1.23-2.94, P <0.01). Preoperative stratification of frailty risk using HFRS may help in predicting postoperative progress and in planning postoperative rehabilitation.

Risk factors for arm lymphedema following breast cancer surgery: a Japanese nationwide database study of 84,022 patients

BACKGROUND

Although arm lymphedema is a well-known complication following breast cancer surgery, previous studies involving a small population showed inconsistent results regarding the risk. Therefore, we examined the risk factors using a Japanese nationwide database.

METHODS

Female patients who underwent breast cancer surgery from April, 2016, to March, 2020, were identified from a Japanese nationwide database. Multivariable survival analyses for 19 baseline factors (12 patient characteristics, four tumor characteristics, and three surgical procedures) were conducted to investigate risk factors associated with treatments for postoperative lymphedema (such as lymphatic bypass, compositive drainage therapy, hospitalization, and Kampo use) with a multilevel model to adjust for within-hospital clustering. We also conducted multivariable analysis for five postoperative factors (two local complications and three postoperative therapies) with adjustment for 19 baseline factors.

RESULTS

The study included 84,022 patients; 1547 (1.8%) received treatments for lymphedema during a median follow-up of 119 weeks (interquartile range, 59-187 weeks). Young age, obesity, smoking, collagen diseases, advanced cancer stage, total mastectomy, axillary dissection, postoperative bleeding, chemotherapy, and radiotherapy were identified as risk factors. Postoperative chemotherapy (hazard ratio, 3.78 [95% confidence interval, 3.35-4.26]) and axillary dissection (2.46 [1.95-3.11]) showed the highest odds ratio among the risk factors. The cumulative probabilities in high-risk patients reached approximately 3% at 1 year and 6% at 4 years after surgery.

CONCLUSIONS

This study identified several risk factors for postoperative lymphedema in breast cancer surgery. The treatment initiation increased markedly within the first year and gradually after 1 year post-surgery.

Intensive Care Unit versus High-dependency Care Unit for COVID-19 Patients with Invasive Mechanical Ventilation

Rationale: High-dependency care units (HDUs), also termed "intermediate care units", "step-down units", or "respiratory HDUs", are areas in which degrees of patient care and costs are between those of the intensive care unit (ICU) and the general ward. In general, patients requiring mechanical ventilation are treated in the ICU rather than in the HDU, except for the use of HDU beds as surge capacity beds during a massive strain; however, the HDU, as well as ICU, are used as the standard care units for mechanically ventilated patients with coronavirus disease (COVID-19) in Japan. Objectives: To assess the outcomes of patients with COVID-19 with invasive mechanical ventilation treated in the HDU versus those treated in the ICU. Methods: In this retrospective cohort study, we used a multicenter inpatient database in Japan to identify mechanically ventilated patients with COVID-19 in the ICU or HDU on the start day of invasive mechanical ventilation from February 10, 2020, to November 30, 2021. The primary outcome was in-hospital mortality within 30 days from the start of the first invasive mechanical ventilation. Propensity score matching was performed to compare the outcomes of patients treated in the ICU with those treated in the HDU. Results: Of 1,985 eligible patients with COVID-19 with invasive mechanical ventilation, 1,303 (66%) were treated in the ICU, and 682 (34%) were treated in the HDU on the start day of invasive mechanical ventilation. After propensity score matching, patients treated in the ICU had significantly lower in-hospital mortality within 30 days than those treated in the HDU (18.3% vs. 24.2%; risk difference, -5.8%; 95% confidence interval, -10.9% to -0.8%). Conclusions: This multicenter observational study in Japan suggests that care for mechanically ventilated patients with COVID-19 in the ICU may significantly reduce in-hospital mortality within 30 days compared with care in the HDU. Establishing a critical care system that would allow patients with COVID-19 requiring ventilators to be treated in the ICU is desirable. Because this study was an observational study, our finding represents an association, not causation. Further studies of different critical care systems are warranted to confirm our findings.

Validation study on definition of cause of death in Japanese claims data

Identifying the cause of death is important for the study of end-of-life patients using claims data in Japan. However, the validity of how cause of death is identified using claims data remains unknown. Therefore, this study aimed to verify the validity of the method used to identify the cause of death based on Japanese claims data. Our study population included patients who died at two institutions between January 1, 2018 and December 31, 2019. Claims data consisted of medical data and Diagnosis Procedure Combination (DPC) data, and five definitions developed from disease classification in each dataset were compared with death certificates. Nine causes of death, including cancer, were included in the study. The definition with the highest positive predictive values (PPVs) and sensitivities in this study was the combination of "main disease" in both medical and DPC data. For cancer, these definitions had PPVs and sensitivities of > 90%. For heart disease, these definitions had PPVs of > 50% and sensitivities of > 70%. For cerebrovascular disease, these definitions had PPVs of > 80% and sensitivities of> 70%. For other causes of death, PPVs and sensitivities were < 50% for most definitions. Based on these results, we recommend definitions with a combination of "main disease" in both medical and DPC data for cancer and cerebrovascular disease. However, a clear argument cannot be made for other causes of death because of the small sample size. Therefore, the results of this study can be used with confidence for cancer and cerebrovascular disease but should be used with caution for other causes of death.

Relationship between institutional intensive care volume prior to the COVID-19 pandemic and in-hospital death in ventilated patients with severe COVID-19

We aimed to evaluate the association between ICU patient volume before the COVID-19 pandemic and the outcomes of ventilated COVID-19 patients. We analyzed ventilated patients with COVID-19 aged > 17 years and enrolled in the J-RECOVER study, a retrospective multicenter observational study conducted in Japan between January and September 2020. Based on the number of patients admitted to the ICU between January and December 2019, the top third institutions were defined as high-volume centers, the middle third ones as middle-volume centers, and the bottom third ones as low-volume centers. The primary outcome measure was in-hospital mortality. Multivariate logistic regression analysis for in-hospital mortality and ICU patient volume was performed after adjusting for multiple propensity scores. Among 461 patients, 158, 158, and 145 patients were admitted to low-volume (20 institutions), middle-volume (14 institutions), and high-volume (13 institutions) centers, respectively. 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, 1.11 [95% confidence interval (CI): 0.55-2.25] and adjusted odds ratio, 0.81 [95% CI: 0.31-1.94], respectively). In conclusion, institutional intensive care patient volume prior to the COVID-19 pandemic was not significantly associated with in-hospital death in ventilated COVID-19 patients.

Impact of body mass index on in-hospital mortality in older patients hospitalized for bacterial pneumonia with non-dialysis-dependent chronic kidney disease

BACKGROUND

Low body mass index (BMI) in older individuals with decreased kidney function is important because of its association with poor prognosis and frailty. Herein, we aimed to clarify the association between BMI and in-hospital mortality among older patients with non-dialysis-dependent chronic kidney disease (CKD) stratified by kidney function.

METHODS

Using data from the Medical Vision Database, this multicentre cohort study included people aged ≥ 60 years with an estimated glomerular filtration rate of < 60 ml/min/1.73 m² but without dialysis dependency, hospitalised for bacterial pneumonia during 2014-2019. We compared the risk of in-hospital death between patients with BMI categories based on the quartiles (low, medium-low, medium-high, and high) setting medium-high BMI as a reference. We further assessed the association with BMI using a cubic spline, setting BMI as a nonlinear continuous variable and a BMI of 22 kg/m² as a reference. We also evaluated the association between BMI and kidney function using a generalised additive model adjusted for interaction terms between nonlinear continuous BMI and kidney function.

RESULTS

We obtained data for 3,952 patients, with 350 (8.9%) in-hospital deaths. When compared with medium-high BMI, low BMI was associated with an increased risk of death and longer hospital stay, whereas the other two categories were comparable. Models using a cubic spline showing an association between BMI and in-hospital death showed an L-shaped curve; BMI < 22.0 kg/m² was associated with an increased risk for mortality, and at a BMI of 18.5 kg/m², the odds ratio was 1.43 with a 95% confidence interval of 1.26-1.61 when compared with a BMI of 22.0 kg/m². Analysis of the interactive effects of kidney function using the generalised additive model showed that a protective association of high BMI tapered along with decreased kidney function.

CONCLUSIONS

This cohort study suggests not only that lower BMI and low kidney function are associated with in-hospital mortality independently but also that the protective effects of high BMI weaken as kidney function decreases via the analysis of the interaction terms. This study highlights the necessity for the prevention of underweight and demonstrates the interaction between BMI and kidney function in older patients with non-dialysis-dependent CKD.

Intensive Care Unit Occupancy in Japan, 2015-2018: A Nationwide Inpatient Database Study

BACKGROUND

Detailed data on intensive care unit (ICU) occupancy in Japan are lacking. Using a nationwide inpatient database in Japan, we aimed to assess ICU bed occupancy to guide critical care utilization planning.

METHODS

We identified all ICU patients admitted from January 1, 2015 to December 31, 2018 to ICU-equipped hospitals participating in the Japanese Diagnosis Procedure Combination inpatient database. We assessed the trends in daily occupancy by counting the total number of occupied ICU beds on a given day divided by the total number of licensed ICU beds in the participating hospitals. We also assessed ICU occupancy for patients with mechanical ventilation, patients with extracorporeal membrane oxygenation, and patients without life-supportive therapies.

RESULTS

Over the 4 study years, 1,379,618 ICU patients were admitted to 495 hospitals equipped with 5,341 ICU beds, accounting for 75% of all ICU beds in Japan. Mean ICU occupancy on any given day was 60%, with a range of 45.0% to 72.5%. Mean ICU occupancy did not change over the 4 years. Mean ICU occupancy was about 9% higher on weekdays than on weekends and about 5% higher in the coldest season than in the warmest season. For patients with mechanical ventilation, patients with extracorporeal membrane oxygenation, and patients without life-supportive therapies, mean ICU occupancy was 24%, 0.5%, and 30%, respectively.

CONCLUSION

Only one-fourth of ICU beds were occupied by mechanically ventilated patients, suggesting that the critical care system in Japan has substantial surge capacity under normal temporal variation to care for critically ill patients.

Impact of the COVID-19 pandemic on critical care utilization in Japan: a nationwide inpatient database study

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has disrupted critical care services worldwide. Examining how critical care systems responded to the COVID-19 pandemic on a national level will be useful in setting future critical care plans. The present study aimed to describe the utilization of critical care services before and during the COVID-19 pandemic using a nationwide Japanese inpatient administrative database.

METHODS

All patients admitted to an intensive care unit (ICU) or a high-dependency care unit (HDU) from February 9, 2019, to February 8, 2021, in the Japanese Diagnosis Procedure Combination inpatient database were included. February 9, 2020, was used as the breakpoint separating the periods before and during COVID-19 pandemic. Hospital and patient characteristics were compared before and during the COVID-19 pandemic. Change in ICU and HDU bed occupancy before and during the COVID-19 pandemic was evaluated using interrupted time-series analysis.

RESULTS

The number of ICU patients before and during the COVID-19 pandemic was 297,679 and 277,799, respectively, and the number of HDU patients was 408,005 and 384,647, respectively. In the participating hospitals (383 ICU-equipped hospitals and 460 HDU-equipped hospitals), the number of hospitals which increased the ICU and HDU beds capacity were 14 (3.7%) and 33 (7.2%), respectively. Patient characteristics and outcomes in ICU and HDU were similar before and during the COVID-19 pandemic except main etiology for admission of COVID-19. The mean ICU bed occupancy before and during the COVID-19 pandemic was 51.5% and 47.5%, respectively. The interrupted time-series analysis showed a downward level change in ICU bed occupancy during the COVID-19 pandemic (- 4.29%, 95% confidence intervals - 5.69 to - 2.88%), and HDU bed occupancy showed similar trends. Of 383 hospitals with ICUs, 232 (60.6%) treated COVID-19 patients in their ICUs. Their annual hospital case volume of COVID-19 ICU patients varied greatly, with a median of 10 (interquartile range 3-25, min 1, max 444).

CONCLUSIONS

The ICU and HDU bed capacity did not increase while their bed occupancy decreased during the COVID-19 pandemic in Japan. There was no change in clinicians' decision-making to forego ICU/HDU care for selected patients, and there was no progress in the centralization of critically ill COVID-19 patients.

Corticosteroid use with extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest: A nationwide observational study

Aim

Several studies have reported that corticosteroid administration for cardiac arrest patients may improve outcomes. However, these previous studies have not examined the effect of corticosteroid use in out-of-hospital cardiac arrest (OHCA) patients administered extracorporeal cardiopulmonary resuscitation (ECPR). Therefore, we aimed to examine the effectiveness of corticosteroids in OHCA patients administered ECPR.

Methods

Using the Japanese Diagnosis Procedure Combination inpatient database, we included OHCA patients who were administered ECPR on the day of admission between July 2010 and March 2019. The patients were categorized into the corticosteroid and control groups according to whether they received corticosteroids on the day of admission or not. The primary outcome was in-hospital mortality and the secondary outcomes included percentages of neurologically favorable survival, major bleeding complications, and infection-related complications. We compared the outcomes using a propensity score matching analysis.

Results

We identified 6,142 eligible patients (459 vs 5,683, the corticosteroid and control group, respectively). One-to-four propensity score matching analysis (457 vs 1,827) showed in-hospital mortality was significantly higher in the corticosteroid group compared with the control group (82.1% vs 76.6%; risk difference, 5.5%; 95% CI, 1.5 to 9.5%). Neurologically favorable outcomes did not differ between the two groups (13.6% vs 16.9%; risk difference, -3.3%; 95% CI, -6.9 to 0.3%). The percentage of major bleeding complications and infection-related complications did not significantly differ between the two groups.

Conclusions

The results of this study demonstrated that administration of corticosteroids on the day of admission to OHCA patients administered ECPR was associated with increased in-hospital mortality.

Short-Term Outcomes of Epidural Analgesia in Minimally Invasive Esophagectomy for Esophageal Cancer: Nationwide Inpatient Data Study in Japan

BACKGROUND

Studies have shown that epidural analgesia (EDA) is associated with a decreased risk of pneumonia and anastomotic leakage after esophagectomy, and several guidelines strongly recommend EDA use after esophagectomy. However, the benefit of EDA use in minimally invasive esophagectomy (MIE) remains unclear.

OBJECTIVE

The aim of this retrospective study was to compare the short-term outcomes between patients with and without EDA undergoing MIE for esophageal cancer.

METHODS

Data of patients who underwent oncologic MIE (April 2014-March 2019) were extracted from a Japanese nationwide inpatient database. Stabilized inverse probability of treatment weighting (IPTW), propensity score matching, and instrumental variable analyses were performed to investigate the associations between EDA use and short-term outcomes, adjusting for potential confounders.

RESULTS

Among 12,688 eligible patients, EDA was used in 9954 (78.5%) patients. In-hospital mortality, respiratory complications, and anastomotic leakage occurred in 230 (1.8%), 2139 (16.9%), and 1557 (12.3%) patients, respectively. In stabilized IPTW, EDA use was significantly associated with decreased in-hospital mortality (odds ratio [OR] 0.46 [95% confidence interval 0.34-0.61]), respiratory complications (OR 0.74 [0.66-0.84]), and anastomotic leakage (OR 0.77 [0.67-0.88]). EDA use was also associated with decreased prolonged mechanical ventilation, unplanned intubation, nonsteroidal anti-inflammatory drug use, acetaminophen use, postoperative length of stay, and total hospitalization costs and increased vasopressor use. One-to-three propensity score matching and instrumental variable analyses demonstrated equivalent results.

CONCLUSIONS

EDA use in oncologic MIE was associated with low in-hospital mortality as well as decreased respiratory complications, and anastomotic leakage, suggesting the potential advantage of EDA use in MIE.

Risk Factors for Postoperative Bleeding Following Breast Cancer Surgery: A Nationwide Database Study of 477,108 Cases in Japan

BACKGROUND

Although postoperative bleeding is a common and serious complication in breast cancer surgery, the risk factors remain unclear. Therefore, we examined the risk factors using a Japanese nationwide database.

METHODS

Patients who underwent breast cancer surgery between July 2010 and March 2020 were identified from a Japanese nationwide database. Multivariable analyses for 47 candidate risk factors (4 patient characteristics, 32 comorbidities, 5 tumor characteristics, 3 preoperative drug uses, and 3 surgical procedures) were conducted to investigate risk factors associated with postoperative bleeding requiring reoperation. Two sensitivity analyses were conducted: an analysis for postoperative bleeding with or without reoperation and an analysis for patients who underwent total mastectomy without breast reconstruction.

RESULTS

Among the 477,108 patients included, 7048 (1.5%) developed postoperative bleeding and 2357 (0.5%) underwent reoperation for postoperative bleeding. Male sex, old age, body mass index ≥ 25.0 kg/m², several comorbidities (deficiency anemia, cardiac arrhythmias, hypertension, liver disease, psychoses, and valvular disease), preoperative heparin use, and several procedures were identified as risk factors. Deficiency anemia showed the highest odds ratio among the risk factors (4.41 [95% confidence interval, 3.63-5.36]). High odds ratios were also observed in total mastectomy (2.32 [2.10-2.56]), flap reconstruction (1.93 [1.55-2.40]), and preoperative heparin use (1.64 [1.26-2.14]). The results corresponded with the sensitivity analyses.

CONCLUSIONS

This study identified several risk factors for postoperative bleeding in breast cancer surgery, such as high body mass index, anemia, cardiovascular diseases, liver diseases, psychoses, preoperative heparin use, and surgical procedures.

A survey of the implementation rate of cardiac rehabilitation for patients with heart disease undergoing device implantation in Japan

Background

The effect of cardiac rehabilitation (CR) on patients undergoing device implantation (DI) for arrhythmias has been reported; however, the implementation status of these patients has not been clarified. This study aimed to verify the implementation status of CR for patients with heart disease who have undergone DI using real-world data.

Methods

This was an observational study using a nationwide administrative database associated with the diagnosis procedure combination (DPC) system in Japan (2014-2018). Subjects were patients with heart disease (70 667 cases) who underwent DI during the above scheduled hospitalization period. The overall rate of CR and the background factors of the subjects were verified.

Results

The CR rate for patients with heart disease who underwent DI during hospitalization was 23%, and the CR rate for patients with comorbid heart failure who underwent DI was only 32%. It was confirmed that progressing age was associated with a higher CR implementation rate. The lower the Barthel index score at the time of admission, the higher the CR implementation rate.

Conclusions

CR was performed for only one-quarter of all the patients during admission for DI and just one-third of the patients for DI with heart failure. Most of these patients were elderly and had a decreased ability to perform activities of daily living. The DPC data are subject to various limitations, and further research is necessary.

Perioperative outcomes of laparoscopically assisted anorectoplasty versus conventional procedures for anorectal malformation: a retrospective nationwide database study

PURPOSE

This study aimed to compare the perioperative outcomes of laparoscopically assisted anorectoplasty (LAARP) and conventional procedures (CPs) for anorectal malformation (ARM) using a national inpatient database in Japan.

METHODS

Using the Diagnosis Procedure Combination database, we identified patients who underwent anorectoplasty for high- or intermediate-type ARMs from 2010 to 2019. Primary outcomes were postoperative rectal prolapse, anal stenosis, and general complications. Secondary outcomes were the duration of anesthesia and length of hospital stay. We performed 1:2 propensity score-matched analyses to compare the outcomes between the LAARP and CP groups.

RESULTS

We identified 1005 eligible patients, comprising 286 and 719 patients who underwent LAARP and CP, respectively. The propensity score-matched groups included 281 patients with LAARP and 562 with CP. The LAARP group showed a higher proportion of rectal prolapse (21.4% vs. 8.5%; odds ratio, 2.91; 95% confidence interval [CI], 1.89-4.48; p < 0.001) and longer duration of anesthesia (462 min vs. 365 min; difference, 90 min; 95% CI 43-137; p < 0.001) than the CP group. No significant differences were found in other outcomes.

CONCLUSION

LAARP had worse outcomes than CP in terms of rectal prolapse. Thus, we propose that LAARP may require technical refinement to improve patient outcomes.

Low-Flow Duration and Outcomes of Extracorporeal Cardiopulmonary Resuscitation in Adults With In-Hospital Cardiac Arrest: A Nationwide Inpatient Database Study

OBJECTIVES

Although existing guidelines recommend commencing cannulation for extracorporeal cardiopulmonary resuscitation (ECPR) within 10-20 minutes of failed conventional resuscitation efforts for cardiac arrest, there is little supportive evidence. The present study aimed to determine the association of low-flow duration with survival-to-discharge rate in in-hospital cardiac arrest patients who received ECPR.

DESIGN

A nationwide retrospective cohort study analyzed a nationwide inpatient database in Japan. Low-flow duration was defined as the time interval from initiation of chest compression to termination of chest compression. We assessed the association between low-flow duration and survival-to-discharge rate by predicting estimates with covariate adjustment stratified by categories of low-flow duration.

SETTING

More than 1,600 acute-care hospitals in Japan.

PATIENTS

All in-hospital cardiac arrest patients greater than or equal to 18 years old who received ECPR during hospitalization from July 2010 to March 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among 303,319 in-hospital cardiac arrest patients, 9,844 (3.2%) received ECPR in 697 hospitals during the study period and 9,433 were eligible in the study. The overall survival-to-discharge rate was 20.5% (1,932/9,433). The median low-flow duration was 26.0 minutes (interquartile range, 12.0-46.0 min) in the overall cohort. The highest and lowest estimated survival-to-discharge rates were 35.1% in the group with low-flow duration 0-5 minutes and 7.9% in the group with low-flow duration greater than 90 minutes. The estimated survival-to-discharge rate dropped sharply by about 20% during the first 35 minutes of low-flow duration (decreasing by about 3% every 5 min), followed by small decreases after the first 35 minutes.

CONCLUSIONS

The estimated survival-to-discharge rate was markedly decreased by approximately 20% during the first 35 minutes of low-flow duration. Whether we should wait for the first 10-20 minutes of cardiac arrest without preparing for ECPR is questionable.

Delayed Tetracycline Initiation Increases Mortality Risk in Patients With Japanese Spotted Fever: Retrospective Analysis Using a National Inpatient Database

Background

This study aimed to determine the relationship between time to tetracycline therapy initiation and disease outcome in patients hospitalized with Japanese spotted fever (JSF).

Methods

Patients with JSF enrolled in the Japanese Diagnosis Procedure Combination database from July 2010 to March 2021 were included in the analysis. Patients who received tetracycline on the day of admission were compared with those who received tetracycline later during their hospital stay using inverse probability of treatment weighting. The primary outcome was in-hospital mortality. Secondary outcomes were total hospitalization cost and length of hospital stay.

Results

A total of 1360 patients were included, of whom 1060 (78%) received tetracycline on the day of admission (early tetracycline group), and 300 (22%) received tetracycline later (delayed tetracycline group). Patients in the delayed tetracycline group had significantly higher in-hospital mortality than those in the early tetracycline group (3.9% vs 1.4%; odds ratio, 2.94; 95% CI, 1.34–6.47), significantly higher hospitalization costs, and longer hospital stays than those in the early tetracycline group.

Conclusions

The prognosis of patients with JSF is worse if tetracycline administration is delayed; therefore, physicians should initiate tetracycline on admission if JSF is suspected as a possible diagnosis.

Efficacy of initial high- versus low-dose intravenous corticosteroid therapy in patients with acute exacerbation of idiopathic interstitial pneumonia: A nationwide observational study

BACKGROUND

Acute exacerbation of idiopathic interstitial pneumonias (AE-IIPs) has a high mortality. However, there is no established treatment for AE-IIPs. Therefore, we aimed to compare the efficacy of high- and low-dose corticosteroid therapies in AE-IIPs patients.

METHODS

Data were retrospectively collected from the Japanese Diagnosis Procedure Combination database from July 2010 to March 2018. Adult patients with AE-IIPs who received high-dose (methylprednisolone at a dose of 500-1000 mg/day for 3 days starting within 4 days after admission) or low-dose (methylprednisolone at a dose of 100-200 mg/day for at least 5 days starting within 4 days after admission) corticosteroid therapy were identified. Eligible patients (n = 17,317) were divided into the high-dose (n = 16,998) and low-dose (n = 319) groups. A stabilized inverse probability of treatment weighting using propensity scores was performed to compare outcomes between the groups.

RESULTS

The primary outcome was in-hospital mortality, and the secondary outcomes were 28-day mortality, infections during hospitalization, length of hospitalization, duration of steroid use, and discharge to home. The in-hospital mortality rates of the high- and low-dose corticosteroid groups were 50.6% and 47.0%, respectively. In-hospital mortality did not significantly differ between the two groups after stabilized inverse probability of treatment weighting, and the odds ratio in the low-dose corticosteroid group was 0.86 (95% confidence interval: 0.64-1.16; p = 0.33). The secondary outcomes also did not significantly differ between the groups.

CONCLUSIONS

There was no significant difference in outcomes between patients with AE-IIPs who received high- and low-dose corticosteroid therapies.

One-year costs of incisional glaucoma surgery and laser therapy

BACKGROUND

This study aimed to calculate one-year total costs of incisional glaucoma surgery and laser therapy in a real-world clinical setting.

METHODS

We conducted a retrospective cohort study from July 2010 to March 2021 using the Diagnosis Procedure Combination database. We included patients hospitalized for incisional glaucoma surgery (trabeculectomy, trabeculotomy, tube shunt surgery, Ex-PRESS surgery, or iStent implantation) or laser therapy (laser peripheral iridotomy, surgical iridectomy, laser trabeculoplasty, cyclocryotherapy, or cyclophotocoagulation). The outcomes were total costs, including costs of hospitalization, re-admissions, antiglaucoma drugs, ophthalmic examinations, and outpatient visits for incisional glaucoma surgery and laser therapy within one year.

RESULTS

We identified 49,202 eligible hospitalizations. The one-year median total cost was 707,497 yen [interquartile range: 546,887-944,664 yen]. The median total cost was the highest in patients undergoing tube shunt surgery, followed by Ex-PRESS surgery, iStent implantation, and trabeculectomy. The number and cost of postoperative outpatient visits and length of hospital stay were higher in patients who underwent trabeculectomy and Ex-PRESS surgery than in those after tube shunt surgery. The total costs of laser therapies were lower than those of incisional glaucoma surgeries. The total cost was the highest in the 0-19 age group (856,398 [649,419-1,258,844] yen).

CONCLUSIONS

Tube shunt surgery was the costliest in terms of total one-year costs. Trabeculectomy and Ex-PRESS surgery were associated with long hospital stays and incurred high postoperative costs. The costs of laser therapies were relatively low. However, cost-effectiveness of laser therapies compared with incisional surgeries needs to be analyzed in future research.

Association between intravenous immunoglobulin dose and outcomes in patients with acute Kawasaki disease

The most effective dosage of intravenous immunoglobulin (IVIG) to prevent coronary artery abnormalities (CAAs) in patients with acute Kawasaki disease (KD) remains unknown. This study aimed to identify the appropriate dose of IVIG to be administered to patients with acute KD, using a national inpatient database in Japan. We used the Diagnostic Procedure Combination database to identify KD patients treated with IVIG between 2010 and 2020. The primary outcome was the proportion of CAAs upon discharge. Secondary outcomes included IVIG resistance, length of stay, and medical costs. Data from 88,223 patients were extracted from the database. We found a U-shaped association between IVIG dose and the proportion of CAA, with the bottom of the curve at approximately 2.0 g/kg; the odds ratio (95% confidence interval [CI]) was 1.34 (1.26-1.43) for 1.8 g/kg and 1.80 (1.29-2.51) for 2.4 g/kg with reference to 2.0 g/kg for CAA. Similarly, IVIG dose had a U-shaped association with the proportion of IVIG resistance, with the bottom of the curve at approximately 2.0 g/kg; the odds ratio (95% CI) was 1.39 (1.36-1.42) for 1.8 g/kg and 8.95 (8.15-9.83) for 2.4 g/kg with reference to 2.0 g/kg for IVIG resistance. Additionally, IVIG dosage was found to have U-shaped associations with the length of stay and medical costs, with the bottom of the curve at approximately 2 g/kg.   Conclusions: IVIG with a dose of 2 g/kg was considered appropriate for the initial treatment of KD. What is Known: • For treatments of acute Kawasaki Disease (KD), IVIG has been the most recommended to reduce fever early and prevent complications of CAAs. Few studies have shown the most effective dosage of IVIG to be administered to prevent CAAs. What is New: • 2 g/kg intravenous immunoglobulin was considered appropriate for the initial treatment of Kawasaki disease.

Perioperative outcomes of thyroid cancer surgery in children and adults: a nationwide inpatient database study in Japan

BACKGROUND

Little is known about perioperative outcomes after pediatric thyroidectomy. This study was performed to compare perioperative outcomes between children and adults undergoing thyroid cancer surgery using a nationwide inpatient database in Japan.

METHODS

Using the Japanese Diagnosis Procedure Combination database, we identified patients aged 0 to 40 years with thyroid cancer who underwent thyroidectomy from July 2010 to March 2020. To compare the occurrence of in-hospital morbidities including local complications (e.g., recurrent laryngeal nerve paralysis, postoperative bleeding), duration of anesthesia, postoperative length of stay, and total hospitalization costs between children (0-18 years) and adults (19-40 years), we used multivariable logistic regression analysis for the occurrence of in-hospital morbidities and linear regression for other outcomes.

RESULTS

For 16,016 eligible patients (666 children vs. 15,350 adults), no significant differences between the two groups were found in any in-hospital morbidity (5.4% vs. 5.9%; adjusted odds ratio [OR], 0.80; 95% confidence interval [CI], 0.57-1.14; P = 0.23), local complications (5.0% vs. 5.5%; OR, 0.80; 95% CI, 0.55-1.15; P = 0.22), recurrent laryngeal nerve paralysis (2.1% vs. 2.4%; OR, 0.78; 95% CI, 0.45-1.35; P = 0.37), or postoperative bleeding (1.7% vs. 1.4%; OR, 0.99; 95% CI, 0.53-1.87; P = 0.98). Children showed a longer duration of anesthesia (difference, 20 minutes; 95% CI, 13-27; P < 0.001) and higher total costs (difference, 445 US dollars; 95% CI, 239-651; P < 0.001) than adults.

CONCLUSION

This large nationwide cohort study showed no significant difference in perioperative complications between children and adults undergoing thyroid cancer surgery.

Descriptive epidemiology of COVID-19 in Japan 2020: insights from a multihospital database

BACKGROUND

Epidemiological data are essential for developing strategies against the current coronavirus disease 2019 (COVID-19) pandemic. Data on COVID-19 epidemiology in Japan are limited owing to a focus on specific regions and patient groups, particularly in the early phase of the pandemic.

METHODS

We investigated COVID-19 epidemiology in Japan in 2020 using a large nationwide multihospital database containing insurance claim records and medical records. Inclusion criteria were inpatient and outpatient referrals for COVID-19 in 2020. We analyzed demographic data, comorbidities, drug use, severe COVID-19 risk, and clinical course of hospitalized patients (including death).

RESULTS

We identified 11,868 COVID-19 cases from 56 institutions: 6,440 outpatients and 5,428 inpatients. Of the patients, 53.2% had comorbid conditions, the most common of which was tumor (22.1%), and 56.4% were classed as having a high risk of COVID-19. Pharmacological management patterns were generally consistent between the first and second half of 2020, except for glucocorticoid use. The use of unauthorized medications (hydroxychloroquine, ivermectin, and favipiravir) was infrequent. For hospitalized patients, the median length of stay was 10 days, and 2.4% of patients were admitted to intensive care units. Post-COVID-19 all-cause mortality, all-cause 30-day mortality, and in-hospital deaths were recorded for 7.9%, 5.4%, and 4.6% of patients, respectively. Patients with high-risk conditions had a lower survival probability.

CONCLUSIONS

This descriptive study of COVID-19 in 2020 identified differences in care across outpatient and inpatient settings and changes in care delivery as the pandemic progressed. These findings could inform strategies for future infectious disease pandemics.

Outcomes after early versus delayed antibiotic treatment of liver abscess in Japan: A nationwide retrospective cohort study

BACKGROUND

The optimal timing of antibiotic administration in patients with a liver abscess undergoing liver aspiration or drainage is unknown.

METHODS

This was a retrospective cohort study using the Diagnosis Procedure Combination database, a national inpatient database in Japan.

RESULTS

A total of 34,424 patients who were emergently hospitalized due to liver abscess between July 2010 and March 2020 were included. Of these, 31,248 (90.8%) received antibiotics on the day of admission (early antibiotics group), and 3176 (9.2%) did not (delayed antibiotics group). Multivariable logistic regression analyses showed that in-hospital mortality of patients in the early antibiotics group was significantly lower than that in the delayed antibiotics group (odds ratio, 0.61; 95% confidence interval, 0.52-0.72; p <0.001). Patients in the early antibiotics group had a significantly lower proportion of clinical deterioration (odds ratio, 0.73; 95% confidence interval, 0.63-0.84; p <0.001) and shorter length of stay (adjusted difference, -5.2 days; 95% confidence interval, -6.2 to -4.1 days; p <0.001) than those in the delayed antibiotics group.

CONCLUSIONS

Starting antibiotic treatment on the day of admission was associated with lower mortality, a lower proportion of clinical deterioration, and a shorter length of hospital stay.

Association between psoriasis and short-term outcomes of acute myocardial infarction: A matched-pair cohort study using a nationwide inpatient database in Japan

Background

Objective

Methods

Results

Limitations

Conclusion

Early electroconvulsive therapy in patients with bipolar depression: A propensity score-matched analysis using a nationwide inpatient database

OBJECTIVES

Electroconvulsive therapy (ECT) is a widely used treatment for bipolar depression; however, evidence of its effectiveness is not sufficient. This study therefore aimed to evaluate whether early ECT is associated with reduced length of hospital stay.

METHODS

In this retrospective cohort study using the Japanese Diagnosis Procedure Combination database, we identified patients admitted for bipolar depression between April 2010 and March 2018. The primary outcome was length of hospital stay, and the secondary outcome was clinical outcomes and total hospitalization costs. Propensity score-matched analyses were performed to compare the outcomes between patients who received ECT within 8 days of admission (early ECT group) and those who did not (control group).

RESULTS

We identified 5941 eligible patients, comprising 219 in the early ECT group and 5722 in the control group. After 1:4 propensity score matching, patients in the early ECT group had significantly shorter lengths of hospital stay than those in the control group (53 days in the early ECT group and 73 days in the control group; difference: -20.2 days; 95 % confidence interval: -29.2 to -11.2 days). There was no significant difference in total hospitalization costs between the two groups. In-hospital mortality and fatal complications were rare in both groups. The result was similar in the sensitivity analysis using inverse probability of treatment weighting.

LIMITATIONS

Our study was limited by retrospective design and the possibility of unmeasured confounders.

CONCLUSIONS

Early ECT was associated with reduced length of hospital stay without increasing total hospitalization costs in patients with bipolar depression.

Major complications after percutaneous biopsy of native or transplanted liver in pediatric patients: a nationwide inpatient database study in Japan

Aim

Although major complication rates following percutaneous liver biopsy (PLB) have been reported to be higher in children than in adults, scarce data are available regarding pediatric patients stratified by native and transplanted liver. We aimed to assess the factors associated with major complications after percutaneous biopsy of native or transplanted liver using a nationwide inpatient database.

Methods

Using the Japanese Diagnosis Procedure Combination database, we retrospectively identified pediatric patients who underwent PLB between 2010 and 2018. We described major complication rates and analyzed factors associated with major complications following PLB, stratified by native and transplanted liver.

Results

We identified 3584 pediatric PLBs among 1732 patients from 239 hospitals throughout Japan during the study period, including 1310 in the native liver and 2274 in the transplanted liver. Major complications following PLB were observed in 0.5% (n = 18) of the total cases; PLB in the transplanted liver had major complications less frequently than those in the native liver (0.2% vs. 1.0%, p = 0.002). The occurrence of major complications was associated with younger age, liver cancers, unscheduled admission, anemia or coagulation disorders in cases with native liver, while it was associated with younger age alone in cases with transplanted liver.

Conclusions

The present study, using a nationwide database, found that major complications occurred more frequently in pediatric cases with native liver and identified several factors associated with its major complications.

Effectiveness of fluoroquinolone antimicrobials in addition to tetracyclines for Japanese spotted fever: A retrospective analysis using a national inpatient database

OBJECTIVES

This study aim to evaluate the effectiveness of fluoroquinolone (FQ) antimicrobial therapy in combination with tetracyclines (TCs) in patients with Japanese spotted fever (JSF) using a nationwide inpatient database in Japan.

METHODS

We identified hospitalized patients diagnosed with JSF who were enrolled in the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2021. Patients who received FQ plus TC on the day of admission were compared with patients who received TC alone on the day of admission, using inverse probability of treatment weighting. The primary outcome was in-hospital mortality. Secondary outcomes were in-hospital complications, total hospitalization costs, and length of hospital stay.

RESULTS

We identified 1060 eligible patients. Of these, 434 (41%) received FQ plus TC on the day of admission and 626 (59%) received TC alone on the day of admission. Inverse probability of treatment weighting showed no statistically significant differences between the groups in in-hospital mortality, in-hospital complications, total hospitalization costs, and length of hospital stay.

CONCLUSION

This study did not show any significantly improved effectiveness using FQ antimicrobials in combination with TCs for treating JSF. Clinicians may need to be cautious in administering FQ and TC antimicrobials concomitantly in routine practice.

Intensive care unit versus high dependency care unit admission after emergency surgery: a nationwide in-patient registry study

BACKGROUND

The appropriate level of postoperative critical care for patients undergoing emergency surgery is unknown. We aimed to assess the outcomes of postoperative patients treated in the intensive care unit (ICU) and high dependency care unit (HDU) after emergency surgery.

METHODS

Analysis of national in-patient registry data in Japan from July 2010 to March 2018, including patients undergoing one of 10 emergency surgeries on the day of hospital admission. The exposures were ICU or HDU admission on the day of surgery. The primary outcome was in-hospital mortality. We performed multivariable logistic regression analysis adjusted for patient and hospital characteristics. Results are presented as n (%) and odds ratios (ORs) with 95% confidence intervals.

RESULTS

We included 158 149 patients from 646 hospitals. Crude in-hospital mortality for each procedure ranged from 168/8583 (2.0%) for cholecystectomy to 2842/12 958 (21.9%) for patients undergoing surgery for traumatic brain injury. Compared with HDU admission, ICU admission was associated with lower in-hospital mortality among the cohorts for medium-mortality risk procedures (procedure-specific mortality 5-15%) (ICU: 8834/73 616 [12.0%] vs HDU: 2586/25 262 [10.2%]; OR=0.90 [0.85-0.96]; P=0.001), and high-mortality risk procedures (procedures-specific mortality >15%) (ICU: 3445/16 334 [21.1%] vs HDU: 996/4613 [21.6%]; OR=0.86 [0.78-0.96]; P=0.005). There were no differences in mortality for low-mortality risk procedures with procedure-specific mortality <5%.

CONCLUSIONS

In this national registry study, postoperative critical care in ICU was associated with lower in-hospital mortality than in HDU for patients undergoing medium-risk and high-risk emergency surgery. Further research is needed to understand the role of critical care for surgical patients.

Rehabilitation of Patients With Acute Ischemic Stroke Who Required Assistance Before Hospitalization Contributes to Improvement in Activities of Daily Living: A Nationwide Database Cohort Study

OBJECTIVE

To assess the effect of early implementation of and longer daily duration of rehabilitation on patients with acute ischemic stroke who require assistance with activities of daily living (ADL) before hospital admission.

DESIGN

Nationwide, cohort, observational study from April 2018 to March 2019.

SETTING

Acute care hospitals in Japan.

PARTICIPANTS

The Japanese national Diagnosis Procedure Combination database was searched for the period between April 2018 and March 2019. Of the 330,672 patients with ischemic strokes identified, 53,523 met the inclusion criteria of being older than 20 years, having a prehospital modified Rankin Scale score of 3, 4, or 5, and having undergone rehabilitation (N=53,523).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Improvement in ADL from admission to discharge using the Barthel Index. The effects of the following 3 rehabilitation variables on ADL improvement were evaluated: (1) average daily duration of rehabilitation; (2) rehabilitation started within 3 days after admission (early rehabilitation); and (3) rehabilitation started 1 day after admission (very early rehabilitation).

RESULTS

Early rehabilitation was significantly associated with improvements in ADL (odds ratio, 1.19; 95% confidence interval, 1.10-1.28; P≤.001). A longer duration of rehabilitation was also significantly associated with ADL improvement (≥2.0 hours: odds ratio, 2.49; 95% confidence interval, 2.26-2.75; P≤.001) compared with a ≤1 hour of rehabilitation (1.1-2.0 hours: odds ratio, 1.35; 95% confidence interval, 1.29-1.42; P≤.001).

CONCLUSIONS

Early implementation of rehabilitation and a longer duration of rehabilitation per day improved the ADL of patients who required assistance before the onset of cerebral infarction.