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

Intensive care unit versus high-dependency care unit for mechanically ventilated patients with pneumonia: a nationwide comparative effectiveness study

Background

Many mechanically ventilated patients in Japan are treated in high-dependency care units (HDUs) rather than intensive care units (ICUs). HDUs can provide intermediate-level care with reduced costs; however, there is limited evidence on whether mechanically ventilated patients should be treated in the ICU or HDU.

Methods

This was a comparative effectiveness study using a nationwide administrative database in Japan. We identified mechanically ventilated patients with pneumonia in ICU or HDU on the day of admission in the Japanese Diagnosis Procedure Combination inpatient database from April 2014 to March 2019. The primary outcome was 30-day in-hospital mortality. Propensity score matching analysis was performed to compare this outcome between patients treated in the ICU and HDU. The robustness of the analyses was evaluated with multivariable regression, overlap weighting, and instrumental variable analyses.

Findings

Of 14,859 mechanically ventilated patients with pneumonia, 7,528 (51%) were treated in the ICU and 7,331 (49%) were treated in the HDU. After propensity score matching, patients treated in the ICU had significantly lower 30-day in-hospital mortality than did those treated in the HDU (24.0% vs. 31.2%; difference, −7.2%; 95% confidence interval, −10.0% to −4.4%). The multivariable regression, overlap weighting, and instrumental variable analyses showed a similar direction and magnitude of association.

Interpretation

Critical care for mechanically ventilated patients with pneumonia in the ICU was associated with a 7.2% decrease in 30-day in-hospital mortality vs. care in the HDU. Residual confounding may still play a role in the effect estimates.

Funding

This study received funding from Ministry of Health, Labour and Welfare, Japan, and Ministry of Education, Culture, Sports, Science and Technology, Japan.

New machine learning scoring system for predicting postoperative mortality in gastroduodenal ulcer perforation: A study using a Japanese nationwide inpatient database

BACKGROUND

Conventional prediction models for estimating risk of postoperative mortality in gastroduodenal ulcer perforation have suboptimal prediction ability. We aimed to develop and validate new machine learning models and an integer-based score for predicting the postoperative mortality.

METHODS

We retrospectively identified patients with gastroduodenal ulcer perforation who underwent surgical repair, using a nationwide Japanese inpatient database. In a derivation cohort from July 2010 to March 2016, we developed 2 machine learning-based models, Lasso and XGBoost, using 45 candidate predictors, and also developed an integer-based score for clinical use by including important variables in Lasso. In a validation cohort from April 2016 to March 2017, we measured the prediction performances of the models by computing area under the curve and comparing it to the conventional American Society of Anesthesiology risk score.

RESULTS

Of 25,886 patients, 1,176 (4.5%) died after surgical repair. For the validation cohort, Lasso and XGBoost had significantly higher prediction abilities than the American Society of Anesthesiology score (Lasso area under the curve = 0.84; 95% confidence interval 0.81-0.86; American Society of Anesthesiology score area under the curve = 0.70; 95% confidence interval 0.65-0.74, P < .001). The integer-based risk score, which had 13 factors, had a prediction ability similar to those of Lasso and XGBoost (area under the curve = 0.83; 95% confidence interval 0.81-0.86). According to the integer-based score, the mortalities were 0.1%, 2.3%, 9.3%, and 29.0% for the low (score, 0), moderate (1-2), high (3-4), and very high (≥5) score groups, respectively.

CONCLUSION

Machine learning models and the integer-based risk score performed well in predicting risk of postoperative mortality in gastroduodenal ulcer perforation. These models will help in decision making.

Pulmonary disease as a risk factor for transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) is a severe condition characterised by noncardiogenic pulmonary oedema that develops within 6 h of blood transfusion. Patient factors and blood products have both been implicated in the development of TRALI; however, the role of pulmonary disease has not been investigated. We aimed to determine whether pulmonary disease is a risk factor for TRALI.

We conducted a nested case-control study using data from the Diagnosis Procedure Combination database, a nationwide inpatient database in Japan, between July 2010 and March 2015. Case patients who developed TRALI were 1:4-matched with control patients for sex, age and same hospital for receipt of blood transfusion. We conducted a multivariable conditional logistic regression analysis to evaluate the associations of TRALI with various factors including comorbidities, body mass index (BMI) and plasma-containing blood products.

We identified 2 019 501 hospitalised patients who received a blood transfusion. Among these patients, 72 developed TRALI. The 72 case patients had higher proportions of haematological malignancy, trauma and interstitial lung disease (ILD) than the 288 matched control patients. The multivariable conditional logistic regression analysis showed that occurrence of TRALI was associated with ILD (odds ratio, 3.88; 95% confidence interval, 1.11–13.6), BMI ≥25.0 kg·m⁻² (2.10; 1.05–4.24) and plasma-containing blood products (1.94; 1.10–3.42), but not with infectious lung disease or obstructive airway disease.

In conclusion, ILD was an independent risk factor for the development of TRALI. Physicians should be aware of the increased risk of TRALI in patients with ILD.

Physicians should be aware of the risk of developing transfusion-related acute lung injury when performing a blood transfusion in patients with interstitial lung disease.https://bit.ly/3jdoZQP

Comparisons of postoperative outcomes after breast cancer surgery in patients with and without renal replacement therapy: a matched-pair cohort study using a Japanese nationwide inpatient database

BACKGROUND

Although patients receiving renal replacement therapy (RRT) have more comorbidities and higher mortality and morbidity risks than the general population, surgery during breast cancer treatment is crucial because of limitations in anticancer agents for patients with renal insufficiency. We aimed to compare the short-term postoperative outcomes between patients with and without RRT.

METHODS

Patients who underwent surgery for stages 0-III breast cancer between July 2010 and March 2017 were retrospectively identified in a Japanese nationwide inpatient database and divided into those with RRT (RRT group, n = 1547) and those without RRT (control group, n = 364,047). We generated a 1:4 matched-pair cohort matched for age, institution, and fiscal year at admission. We conducted multivariable regression analyses to compare postoperative complications, 30-day readmission, and anesthesia duration between the two groups.

RESULTS

The RRT group was more likely to have comorbidities (95.0% vs. 24.1%) and undergo total mastectomy (64.2% vs. 47.0%) than the control group. The RRT group was not significantly associated with complications (odds ratio 1.18; 95% confidence interval [CI] 0.89-1.56) and 30-day readmission (odds ratio 0.88; 95% CI 0.65-1.18), but was associated with shorter anesthesia duration (difference, - 6.8 min; 95% CI - 10.7 to - 3.0 min) compared with the control group.

CONCLUSIONS

The matched-pair cohort analyses revealed no significant differences in postoperative complications after breast cancer surgery between patients with and without RRT. Breast cancer surgery in patients with RRT may be as safe as that in patients without RRT, if comorbidities other than chronic renal failure are adequately addressed.

Early Electroconvulsive Therapy in Patients With Major Depressive Disorder: A Propensity Score-Matched Analysis Using a Nationwide Inpatient Database in Japan

OBJECTIVES

This study aimed to evaluate whether early electroconvulsive therapy (ECT) can reduce length of hospital stay and total hospitalization costs in major depressive disorder (MDD) patients.

METHODS

Using the Japanese Diagnosis Procedure Combination inpatient database from April 2011 to March 2018 linked with the Annual Report for Functions of Medical Institutions, we identified patients admitted for MDD. Patients who received ECT within 8 days of admission were assigned to the early ECT group and the remaining patients to the control group. The primary outcomes were length of hospital stay and total hospitalization costs. The secondary outcomes were in-hospital mortality and fatal adverse events. Propensity score-matched analyses were performed to compare the outcomes between the 2 groups.

RESULTS

We identified 41,248 eligible patients, comprising 1169 in the early ECT group and 40,079 in the control group. After 1:1 propensity score matching, patients in the early ECT group had significantly shorter length of hospital stay than those in the control group (difference: -12.6 days; 95% confidence interval: -17.4 to -7.7 days). There was no significant difference in total hospitalization costs between the 2 groups. Early ECT was not significantly associated with increased in-hospital mortality or fatal adverse events.

CONCLUSIONS

Early ECT may reduce length of hospital stay without increasing total hospitalization costs or fatal adverse events in patients with MDD.

Validity of initial cancer diagnoses in the Diagnosis Procedure Combination data in Japan

BACKGROUND

In Japan, the Diagnosis Procedure Combination (DPC) data have been used as a nationwide administrative hospital discharge database for clinical studies. However, few studies have evaluated the validity of recorded diagnoses of cancer in the database.

METHODS

We compared the DPC data with hospital-based cancer registries in Osaka Prefecture, Japan to assess the validity of the recorded cancer diagnoses in the DPC data. Fifteen types of cancer were included in the analysis. Cancer stage with tumor-node-metastasis (TNM) classification was assessed for eight cancer types with >400 patients. We evaluated concordance and positive predictive value of cancer diagnosis, and concordance of cancer stage between the DPC data and the hospital-based cancer registry.

RESULTS

In total, we identified 29,180 eligible patients. The five types of cancer with the highest number of patients were as follows: 6,765 (23.2 %) colorectal, 6,476 (22.2 %) stomach, 4,862 (16.7 %) breast, 4,445 (15.2 %) lung, and 2,257 (7.7 %) liver. Concordance of diagnosis ranged from 63.9 %-99.5 %, and twelve of the fifteen types of cancers had concordance of over 90 %. Positive predictive values of diagnosis ranged from 86.8 %-100 %. Regarding cancer stage, the overall degree of concordance was 67.2 % in all patients and the concordance was over 70 % in four types of cancers.

CONCLUSIONS

The DPC data had high validity of cancer diagnosis. However, the potential impact of the misclassifications and low concordance in cancer stage among specific type of cancers in the DPC data should be considered.

Risk factors for early in-hospital death in patients who developed coagulopathy during induction therapy for acute promyelocytic leukemia: a nationwide analysis in Japan

To prevent early death, management of coagulopathy is important in patients with untreated acute promyelocytic leukemia (APL). This study aimed to clarify factors associated with in-hospital death in patients with coagulopathy during induction therapy for APL. We retrospectively identified patients with newly diagnosed APL who received induction therapy including all-trans retinoic acid (ATRA) and developed coagulopathy, using a nationwide inpatient database in Japan. Of 1115 eligible patients, 175 (15%) died at a median of 13 days (interquartile range, 7-30) after admission. In the multivariable analysis, compared with younger patients (aged < 40 years), the occurrence of in-hospital death was significantly more common among older patients (aged ≥ 40 and < 60 years: odds ratio = 2.58 [95% confidence interval: 1.29-5.19]; aged ≥ 60 and < 80 years: 7.66 [3.89-15.10]; aged ≥ 80 years: 16.83 [7.41-38.21]). Delayed initiation of ATRA and no conventional chemotherapy were significantly associated with in-hospital death (1.79 [1.16-2.76] and 2.40 [1.47-3.92], respectively). A total of 699 patients (63%) received anticoagulant therapies, but none of these was significantly associated with lower mortality. Although the present study was constrained by a lack of laboratory findings because of database limitations, the results showed that untreated patients with APL, especially the elderly, had a poor prognosis. Immediate administration of ATRA may reduce in-hospital mortality.

Variations in hip fracture inpatient care in Japan, Korea, and Taiwan: an analysis of health administrative data

BACKGROUND

Little is known about hip fracture inpatient care in East Asia. This study examined the characteristics of patients, hospitals, and regions associated with delivery of hip fracture surgeries across Japan, Korea, and Taiwan. We also analyzed and compared how the resource use and a short-term outcome of the care in index hospitals varied according to factors in the respective health systems.

METHODS

We developed comparable, nationwide, individual-level health insurance claims datasets linked with hospital- and regional-level statistics across the health systems using common protocols. Generalized linear multi-level analyses were conducted on length of stay (LOS) and total cost of index hospitalization as well as inpatient death.

RESULTS

The majority of patients were female and aged 75 or older. The standardized LOS of the hospitalization for hip fracture surgery was 32.5 (S.D. = 18.7) days in Japan, 24.7 (S.D. = 12.4) days in Korea, and 7.1 (S.D. = 2.9) days in Taiwan. The total cost per admission also widely varied across the systems. Hospitals with a high volume of hip fracture surgeries had a lower LOS across all three systems, while other factors associated with LOS and total cost varied across countries.

CONCLUSION

There were wide variations in resource use for hip fracture surgery in the index hospital within and across the three health systems with similar social health insurance schemes in East Asia. Further investigations into the large variations are necessary, along with efforts to overcome the methodological challenges of international comparisons of health system performance.

Intravenous cyclophosphamide in acute exacerbation of rheumatoid arthritis-related interstitial lung disease: A propensity-matched analysis using a nationwide inpatient database

OBJECTIVES

We aimed to investigate the effect of intravenous cyclophosphamide (CYC) as the initial therapy in patients with acute exacerbation of rheumatoid arthritis-related interstitial lung disease.

METHODS

This was a retrospective observational study. Using the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2018, we identified patients with acute exacerbation of rheumatoid arthritis-related interstitial lung disease (RA-ILD) who received high-dose methylprednisolone within 3 days after admission. RA-ILD was defined as having either the diagnosis of RA-ILD or the diagnoses of both RA and ILD, based on the ICD-10 codes recorded by attending physicians. Patients were divided into two groups: those receiving intravenous CYC within 3 days after admission (CYC group) and those who did not (control group). One-to-four propensity-score matching analyses were performed.

RESULTS

A total of 6130 eligible patients were included. After propensity score matching, 129 patients in the CYC group and 516 patients in the control group were further analyzed. 90-day in-hospital mortality, defined as all-cause mortality during hospitalization within 90 days after admission, was not significantly different between the CYC and control groups (50.4% versus 42.2%, hazard ratio 1.20, 95% confidence interval 0.91-1.58). A larger proportion of patients in the CYC group received platelet transfusion than that in the control group (7.0% versus 2.3%, odds ratio 3.05, 95% confidence interval 1.20-7.73).

CONCLUSION

In this retrospective database study, the initial therapy with CYC did not show a survival benefit in patients with acute exacerbation of RA-ILD. CYC was associated with a larger proportion of platelet transfusion.

Body mass index and in-hospital mortality in patients with acute exacerbation of idiopathic pulmonary fibrosis

Background

Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease characterised by chronic fibrosis, and acute exacerbation of IPF (AE-IPF) is the leading cause of death in patients with IPF. Data on the association between the body mass index (BMI) and prognosis of AE-IPF are lacking. This study was performed to evaluate the association between BMI and in-hospital mortality in patients who developed AE-IPF using a national inpatient database.

Methods

Using the Japanese Diagnosis Procedure Combination database, we retrospectively collected data of inpatients with AE-IPF from 1 July, 2010 to 31 March, 2018. We performed a multivariable logistic regression analysis to evaluate the association between all-cause in-hospital mortality and BMI, categorised as underweight (<18.5 kg·m⁻²), low-normal weight (18.5–22.9 kg·m⁻²), high-normal weight (23.0–24.9 kg·m⁻²), overweight (25.0–29.9 kg·m⁻²) and obese (≥30.0 kg·m⁻²).

Results

In total, 14 783 patients were eligible for this study. The in-hospital mortality rate was 59.0%, 55.0%, 53.8%, 54.8% and 46.0% in the underweight, low-normal weight, high-normal weight, overweight and obese groups, respectively. Underweight patients had a significantly higher mortality rate (OR 1.25, 95% CI 1.10–1.42) and obese patients had a significantly lower mortality rate (OR 0.71, 95% CI 0.54–0.94) than low-normal weight patients.

Conclusion

Among patients with AE-IPF, the underweight group had higher mortality and the obese group had lower mortality.

Among patients with acute exacerbation of idiopathic pulmonary fibrosis, underweight patients have higher mortality and obese patients lower mortalityhttps://bit.ly/3eoVMOR

Comparison of postoperative infection after emergency inguinal hernia surgery with enterectomy between mesh repair and non-mesh repair: a national database analysis

PURPOSE

Synthetic non-absorbable mesh is used for elective inguinal hernia repair but is not commonly used for incarcerated or strangulated inguinal hernia requiring enterectomy to reduce the risk of surgical-site infection. This study aimed to evaluate the safety of synthetic non-absorbable mesh repair in patients with incarcerated or strangulated inguinal hernia requiring enterectomy versus non-mesh repair.

METHODS

We analyzed patients with incarcerated or strangulated inguinal hernia with enterectomy from April 2012 to March 2017 using a nationwide inpatient database in Japan. We conducted overlap propensity score-weighted analyses to compare surgical-site infection (SSI), duration of anesthesia, antibiotic use at > 3 days after surgery, postoperative hospital stay, and 30 day readmission. Two sensitivity analyses were performed. First, we compared the proportions of patients requiring wound culture at ≥ 3 days after surgery. Second, we performed overlap propensity score-weighted logistic regression analyses for surgical-site infection.

RESULTS

We identified 668 eligible patients, comprising 223 patients with mesh repair and 445 with non-mesh repair. Overlap propensity score-weighted analyses showed no significant differences between the mesh repair and non-mesh repair groups for SSI (2.5 vs. 2.8%, P = 0.79). Secondary outcomes did not differ significantly between the groups. Proportion of wound culture at ≥ 3 days after surgery was similar in the two groups (11.1 vs. 14.6%, P = 0.18). Logistic regression analysis showed no significant association between mesh repair and SSI (odds ratio, 0.93; 95% confidence interval, 0.34-2.57).

CONCLUSION

Synthetic non-absorbable mesh use may be safe for incarcerated or strangulated inguinal hernia requiring enterectomy.

Treatments and outcomes of generalized pustular psoriasis: A cohort of 1516 patients in a nationwide inpatient database in Japan

BACKGROUND

Because generalized pustular psoriasis (GPP) is rare, there are few studies reporting treatments and outcomes for large numbers of patients.

OBJECTIVE

To report treatments and outcomes in a large cohort of patients hospitalized with GPP.

METHODS

Using a Japanese national inpatient database, we identified 1516 patients with GPP who required hospitalization between July 2010 and March 2019. We categorized patients into 3 medication groups: biologics (294 patients), oral agents without biologics (948 patients), and systemic corticosteroids only (274 patients). We investigated their characteristics, treatments, and outcomes.

RESULTS

Mean age was 66 years (interquartile range: 52-77 years). Fifty patients (3.3%) were admitted to the intensive care unit, 125 (8.2%) required blood pressure support, and 63 (4.2%) died. Patients who received biologics were younger and had fewer comorbidities. In-hospital mortality was lower in the biologics group (1.0% [biologics group] vs 3.7% [oral-agents group] vs 9.1% [corticosteroids-only group]; P < .001) as was morbidity (5.4% vs 8.2% vs 12%, respectively; P = .02). Among those who received biologics, IL-17 inhibitor use increased over time, with in-hospital mortality and morbidity comparable to those of tumor necrosis factor inhibitors.

LIMITATIONS

Retrospective study design. Some patients received multiple medications.

CONCLUSION

Biologic treatments showed favorable outcomes compared with other treatments.

Prognosis and treatment of myositis-associated severe interstitial lung disease: A descriptive study using a nation-wide inpatient database in Japan

OBJECTIVES

The aim of this study was to determine the prognosis, clinical course, and current management of severe interstitial lung disease (ILD) associated with myositis in Japan.

METHODS

We conducted a retrospective descriptive study using a nation-wide database for inpatient care of acute illness in Japan. Among a total of approximately 66 million inpatient admissions, we identified patients with severe ILD associated with polymyositis (PM) or dermatomyositis (DM) which required mechanical ventilation and methylprednisolone pulse therapy (≥1g/day usage of methylprednisolone) from July 2010 to March 2018.

RESULTS

We identified 155 patients with PM and 394 with DM who fulfilled the above criteria. The median age of patients was 65 years old; DM patients were significantly younger than PM patients (64 vs. 68 years old; p<0.001). The numbers of patients who were treated with calcineurin inhibitors, intravenous cyclophosphamide and Polymyxin B immobilized fiber column direct hemoperfusion (PMX-DHP) were 403 (73.4%), 318 (57.9%) and 78 (14.2%), respectively. All these treatments were given significantly more frequently to the patients with DM compared with those with PM. The uses of other treatment options were much less frequent. The median hospital days of initiating methylprednisolone pulse therapy, calcineurin inhibitors, mechanical ventilation, intravenous cyclophosphamide, PMX-DHP, and in-hospital death among patients with DM were 2, 4, 7, 8, 17, and 36, respectively. In-hospital mortality was significantly higher in patients with DM than in those with PM (76.6% vs. 56.8%, p<0.001).

CONCLUSION

The mortality of patients with myositis-associated severe ILD that requires mechanical ventilation is extremely high despite aggressive and prompt interventions.

Clinical features and early post-operative complications of isolated C2 odontoid fractures: a retrospective analysis using a national inpatient database in Japan

PURPOSE

To examine the clinical features and post-treatment complications in patients with isolated C2 odontoid fractures.

METHODS

We extracted data for all patients who were admitted with C2 odontoid fractures from the Japanese Diagnosis Procedure Combination database between July 2010 and March 2017. We then compared the post-treatment complications during hospitalization according to treatment types: conservative treatment (with or without use of halo-vest) and surgery (anterior or posterior spinal fixation).

RESULTS

A total of 3167 patients (1533 men, 1634 women; mean age, 70 years) with isolated C2 odontoid fractures were identified, including 1124 patients (35%) aged ≥ 80 years. Among the total patients, 2476 (78%) received conservative treatment (with halo-vest, 728; without halo-vest, 1748). The remaining 691 patients (22%) underwent surgery (anterior surgery, 129; posterior surgery, 556; combined surgery, 6). There were no differences between the conservative treatment and surgery groups in baseline characteristics and preexisting comorbid conditions except for age (71 vs. 69 years, p = 0.042). In-hospital death occurred in 136 patients (4.3%). There was no significant difference in in-hospital mortality between the two groups (overall, conservative treatment 4.6% vs. surgery 3.0%, p = 0.066; age ≥ 80 years, conservative treatment 7.2% vs. surgery 5.4%, p = 0.34). Use of halo-vest was not associated with increased mortality (with halo-vest 3.7% vs. without halo-vest 5.0%, p = 0.15).

CONCLUSION

The great majority of isolated odontoid fractures occurred in elderly patients. Conservative treatment and surgery had similarly low in-hospital mortality. Use of halo-vest was not associated with an increase in mortality.

Comparing outcomes of nonoperative treatment for adhesive small bowel obstruction with and without antibiotics

INTRODUCTION

Some clinicians administer antibiotics in adhesive SBO treatment to prevent bacterial translocation without evidence confirming reduced sepsis and mortality. We aimed to evaluate the effectiveness of preventive antibiotic administration in nonoperative treatment of adhesive small bowel obstruction (SBO) in a retrospective study.

METHODS

Using a Japanese national inpatient database, we identified 114,786 eligible patients with adhesive SBO and divided patients into a group who did not receive intravenous antibiotics in the initial 2 consecutive days after admission (control group, n = 71,666) and a group who received intravenous antibiotics ≥2 days after admission (antibiotic group, n = 43,120). To compare the in-hospital mortality, occurrence of sepsis, septic shock, Clostridioides difficile colitis, length of stay, and total costs between the two groups, we performed instrumental variable analyses to adjust for measured and unmeasured confounding factors.

RESULTS

Overall, in-hospital mortality was 2.2%, and the occurrence of sepsis was 0.8%. In the instrumental variable analyses, no significant differences were found for in-hospital mortality, occurrence of sepsis, septic shock, Clostridioides difficile colitis, or total hospitalization costs. The antibiotic group showed a longer length of stay than the control group (coefficient, 1.9 days; 95% confidence interval, 0.6-3.2).

CONCLUSIONS

In this large nationwide cohort of patients with adhesive SBO, we found no benefit regarding preventive antibiotic administration in nonoperative treatment; however, antibiotic administration was associated with a longer hospital stay. These results did not support routine administration of antibiotics at admission to prevent bacterial translocation.

Impact of proton pump inhibitors on mortality and severe esophageal injury after catheter ablation for atrial fibrillation: a nationwide retrospective study using propensity score matching

Studies on the protective effects of proton pump inhibitors (PPIs) on mortality and severe esophageal injury after catheter ablation for atrial fibrillation are lacking. However, some reports have recommended use of PPIs for prophylaxis against esophageal injury. We investigated the effects of PPIs on mortality and severe esophageal injury after ablation. We retrospectively extracted data for adult in-patients who received catheter ablation with a diagnosis of atrial fibrillation from July 2010 to March 2018. The patients were divided into two groups: with PPI (PPI group) and without PPI (non-PPI group) administration before or on the day of ablation. The primary composite outcome was all-cause 30-day mortality and incidence of severe esophageal injury with complication (cardiac tamponade, ischemic stroke, or sepsis) within 30 days of ablation. Secondary outcomes included incidence of cardiac tamponade, ischemic stroke, and sepsis within 30 days of ablation. Propensity score matching was performed to compare the primary and secondary outcomes between the two groups. We identified 141,649 eligible patients, comprising 62,558 in the PPI group and 79,091 in the non-PPI group. Propensity score-matching analysis showed that PPI use was not associated with reduced proportion of the primary outcome (adjusted odds ratio 1.02; 95% confidence interval 0.71-1.47). PPI use may not be beneficial for reducing mortality or severe complications.

Pre-transplant Rehabilitation to Decrease the Post-transplant Length of Stay for Hematological Malignancy Patients Undergoing Allo-HSCT

Objectives:

Pre-transplant rehabilitation for hematological malignancy patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) helps improve physical capacity. However, its benefit with respect to post-transplant hospital length of stay (LOS) is unclear. Consequently, the aim of this study was to investigate the effect of pre-transplant rehabilitation on post-transplant LOS for hematological malignancy patients undergoing allo-HSCT.

Methods:

Data on patients diagnosed between April 2014 and March 2017 were collected from the Japanese Diagnosis Procedure Combination database. The patients were identified using the ICD-10 codes C81–85, C90–94, C96, and D46. Multilevel linear regression analyses were conducted to identify the effects of pre-transplant rehabilitation on post-transplant LOS (log transformed).

Results:

In total, 3614 patients were included in the study. Pre-transplant rehabilitation was associated with a significant reduction in post-transplant hospital LOS (β=–0.134, P<0.001).

Conclusions:

Pre-transplant rehabilitation may be an effective strategy for shortening the post-transplant hospital LOS in hematological malignancy patients undergoing allo-HSCT. Consequently, it may be necessary to consider starting rehabilitation before transplantation.

Breast cancer surgery in patients with schizophrenia: short-term outcomes from a nationwide cohort

BACKGROUND

Although patients with schizophrenia have a higher risk of developing breast cancer than the general population, studies that have investigated postoperative complications after breast cancer surgery in patients with schizophrenia are scarce. This study examined associations between schizophrenia and short-term outcomes following breast cancer surgery.

METHODS

Patients who underwent surgery for stage 0-III breast cancer between July 2010 and March 2017 were identified from a Japanese nationwide inpatient database. Multivariable analyses were conducted to compare postoperative complications and hospitalization costs between patients with schizophrenia and those without any psychiatric disorder. Three sensitivity analyses were performed: a 1 : 4 matched-pair cohort analysis with matching for age, institution, and fiscal year at admission; analyses excluding patients with schizophrenia who were not taking antipsychotic medication; and analyses excluding patients with schizophrenia who were admitted to hospital involuntarily.

RESULTS

The study included 3660 patients with schizophrenia and 350 860 without any psychiatric disorder. Patients with schizophrenia had a higher in-hospital morbidity (odds ratio (OR) 1.37, 95 per cent c.i. 1.21 to 1.55), with more postoperative bleeding (OR 1.34, 1.05 to 1.71) surgical-site infections (OR 1.22, 1.04 to 1.43), and sepsis (OR 1.20, 1.03 to 1.41). The total cost of hospitalization (coefficient €743, 95 per cent c.i. 680 to 806) was higher than that for patients without any psychiatric disorder. All sensitivity analyses showed similar results to the main analyses.

CONCLUSION

Although causal inferences remain premature, multivariable regression analyses showed that schizophrenia was associated with greater in-hospital morbidity and higher total cost of hospitalization after breast cancer surgery than in the general population.

Potassium Concentration in Initial Fluid Therapy and In-Hospital Mortality of Patients with Diabetic Ketoacidosis

CONTEXT

Guidelines worldwide recommend potassium replacement of 10 to 40 mmol/L in the initial fluid therapy for patients with diabetic ketoacidosis. However, evidence is lacking as to the association between infused potassium concentration and mortality.

OBJECTIVE

We aimed to determine the association between infused potassium concentration and in-hospital mortality.

METHODS

Using the Japanese Diagnosis Procedure Combination database, we retrospectively identified inpatients admitted for treatment of diabetic ketoacidosis from July 2010 to March 2018. Patients with kidney dysfunction or serum potassium abnormalities were excluded. We evaluated the association of the potassium concentration in the total infused solutions in the first 2 days of hospitalization with 28-day in-hospital mortality using multivariable regression analysis with a cubic spline model. We also assessed the association between potassium concentration and occurrence of hyperkalemia.

RESULTS

We identified 14 216 patients with diabetic ketoacidosis and observed 261 deaths. The quartile cut-points for potassium concentration were 7.7, 11.4, and 16.1 mmol/L. Within the range of approximately 10 to 40 mmol/L, potassium concentration was not associated with occurrence of hyperkalemia or death. Lower potassium concentrations were associated with higher 28-day in-hospital mortality; the odds ratio for patients receiving 8 mmol/L was 1.69 (95% CI, 1.03 to 2.78; reference: 20 mmol/L), and the odds ratio increased monotonically as potassium concentration decreased further.

CONCLUSION

Patients receiving potassium replacement at concentrations of 10 to 40 mmol/L had similar in-hospital mortality rates, whereas lower concentrations were associated with higher mortality.

Comparison of fracture risk between proton pump inhibitors and histamine-2 receptor antagonists in ANCA-associated vasculitis patients: a nested case-control study

OBJECTIVE

Whether acid suppressants [proton pump inhibitors (PPIs) and histamine-2 receptor antagonists (H2RAs)] are associated with bone fractures in patients with ANCA-associated vasculitis (AAV) treated with glucocorticoids remains unclear. This study compared PPIs with H2RAs in terms of the risk of bone fractures in patients with AAV who received in-hospital induction therapy with glucocorticoids.

METHODS

We retrospectively identified 149 patients with fractures among 22 821 patients newly diagnosed with AAV in 1730 hospitals using a nationwide inpatient database from July 2010 to March 2018. We conducted 1:4 case-control matching. Age, sex, duration of AAV treatment and fiscal year were matched between the cases and controls. A conditional logistic regression analysis was conducted to assess the association between acid suppressants and fractures.

RESULTS

Of all enrolled patients with fractures, the median age was 77 years, and 99 (66%) were female. The median duration from AAV treatment to fracture was 52 days. The proportion of patients using PPIs was 91.3% (136 of 149) and 80.2% (478 of 596) in the case and control groups, respectively. Compared with H2RA use, PPI use was significantly associated with fractures after adjustment for age, sex, BMI, smoking habit, Charlson comorbidity index, renal failure, bisphosphonate and same fiscal year according to a multivariate analysis (adjusted odds ratio, 3.76; 95% CI: 1.37, 10.3).

CONCLUSION

PPI users had a higher risk of fractures than H2RA users among mostly advanced-age patients with AAV with remission induction therapy.

Associations between early parenteral nutrition and in-hospital outcomes in underweight patients with gastrointestinal surgery

BACKGROUND & AIMS

Guidelines recommend early parenteral nutrition for malnourished patients. However, the effectiveness of early parenteral nutrition in underweight patients has not been established. This study aimed to determine whether in-hospital outcomes were associated with early parenteral nutrition in underweight gastrointestinal surgery patients with short-term contraindications to early enteral nutrition.

METHODS

We identified underweight adult gastrointestinal surgery patients with short-term contraindications to early enteral nutrition using the Japanese Diagnosis Procedure Combination database from July 2010 to March 2018. We performed propensity-score overlap weighting to compare in-hospital outcomes between patients with and without early parenteral nutrition. The primary outcome was length of hospital stay. The secondary outcomes were total hospitalization cost, hospital-acquired pneumonia, hospital-acquired urinary tract infection, central line-associated bloodstream infection, and all-cause 28-day in-hospital mortality.

RESULTS

We identified 31,898 eligible patients. Early parenteral nutrition was associated with longer hospital stay (19.2 vs. 18.4 days; difference, 0.7 days; 95% CI, 0.1 to 1.4). There were no differences between the patients with and without early parenteral nutrition in total hospitalization cost (difference, US$60; 95% CI, -277 to 397), hospital-acquired pneumonia (risk difference, -0.11%; 95% CI, -0.78 to 0.55), hospital-acquired urinary tract infection (risk difference, 0.03%; 95% CI, -0.08 to 0.14), central line-associated bloodstream infection (risk difference, 0.08%; 95% CI, -0.02 to 0.18), and all-cause 28-day in-hospital mortality (risk difference, 0.31%; 95% CI, -0.07 to 0.69).

CONCLUSIONS

Early parenteral nutrition for underweight gastrointestinal surgery patients with short-term contraindications to early enteral nutrition was associated with longer hospital stay.

In-hospital mortality among patients with invasive non-group A β-hemolytic Streptococcus treated with clindamycin combination therapy: a nationwide cohort study

Aim

Combination treatment with clindamycin is recommended in patients with invasive group A Streptococcus infection; however, whether the same treatment is effective in invasive group B Streptococcus and S. dysgalactiae subspecies equisimilis infections remains unknown. We aimed to investigate whether clindamycin added to standard of care therapy would be effective in patients with invasive non-group A β-hemolytic Streptococcus infections.

Methods

This was a nationwide retrospective cohort study using the Japanese Diagnosis Procedure Combination inpatient database focusing on the period between 2010 and 2018. We extracted data on patients diagnosed with sepsis due to non-group A β-hemolytic Streptococcus. One-to-four propensity score-matching was undertaken to compare patients who were treated with clindamycin within 2 days of admission (clindamycin group) and those who did not (control group). The primary outcome was in-hospital mortality.

Results

We identified 3754 eligible patients during the study period. The patients were divided into the clindamycin (n = 296) and control groups (n = 3458). After one-to-four propensity score matching, we compared 289 and 1156 patients with and without clindamycin, respectively. In-hospital mortality did not significantly differ between the two groups (9.7% versus 10.3%; risk difference 0.3%; 95% confidence interval, -3.5% to 4.2%).

Conclusions

This nationwide database study showed that combination therapy involving the use of clindamycin was not associated with lower in-hospital mortality in patients with invasive non-group A β-hemolytic Streptococcus.

Small-bore feeding tube versus large-bore sump tube for early enteral nutrition in mechanically ventilated patients: A nationwide inpatient database study

BACKGROUND & AIMS

When physicians start nasogastric tube feeding in mechanically ventilated patients, they have two choices of feeding tube device: a large-bore sump tube or a small-bore feeding tube. Some physicians may prefer to initiate enteral nutrition via the large-bore sump tube that is already in place, and others may prefer to use the small-bore feeding tube. However, it remains unknown whether small-bore feeding tubes or large-bore sump tubes are better for early enteral nutrition. The present study aimed to compare outcomes between these two types of feeding tubes in mechanically ventilated patients.

METHODS

Using the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2018, we identified adult patients who underwent invasive mechanical ventilation for ≥2 days in intensive care units and received nasogastric tube feeding within 2 days of starting mechanical ventilation. We categorized these patients as receiving early enteral nutrition via small-bore feeding tube (8- to 12-Fr single-lumen tubes) or via large-bore sump tube. Propensity score-matched analyses were performed to compare 28-day in-hospital mortality and hospital-acquired pneumonia between the two groups.

RESULTS

A total of 79,656 patients were included. Of these patients, 20,178 (25%) were in the small-bore feeding tube group. One-to-one propensity score matching created 20,061 matched pairs. Compared with those in the large-bore sump tube group, patients in the small-bore feeding tube group had significantly higher 28-day in-hospital mortality (17.0% versus 15.6%; hazard ratio, 1.08; 95% confidence interval, 1.03 to 1.14) and a significantly higher prevalence of hospital-acquired pneumonia (9.3% versus 8.5%; odds ratio, 1.11; 95% confidence interval, 1.02 to 1.21).

CONCLUSIONS

This nationwide observational study suggests that small-bore feeding tubes may not be associated with better clinical outcomes but rather with increased mortality and hospital-acquired pneumonia. Because of the uncertainty regarding the mechanism of our findings, further studies are warranted.

Effect of Early Rehabilitation on Physical Function in Patients Undergoing Coronary Artery Bypass Grafting: A Nationwide Inpatient Database Study

It is unclear when to begin rehabilitation after coronary artery bypass grafting (CABG) in the intensive care unit (ICU). Using the Japanese Diagnosis Procedure Combination inpatient database from 2010 to 2018, we identified adult patients who underwent a CABG and who were admitted to the ICU for ≥3 consecutive days from the date of their CABG. Patients who started any rehabilitation program prescribed by physicians or therapists within 3 days of CABG were defined as the early rehabilitation group, and the remaining patients were defined as the usual care group. We identified 30,568 eligible patients, with 13,150 (43%) patients in the early rehabilitation group. An inverse probability of treatment weighting analyses showed that the Barthel Index score at discharge in the early rehabilitation group was significantly higher than that in the usual care group (difference: 3.2; 95% confidence interval: 1.5–4.8). The early rehabilitation group had significantly lower in-hospital mortality, total hospitalization costs, length of ICU stay, and hospital stay vs. the usual care group. Our results suggested that early rehabilitation by physicians or therapists beginning within 3 days of CABG was safe, as suggested by the low mortality and improved physical function in patients who underwent CABG.

Outcomes of laparoscopic versus open pancreatoduodenectomy: A nationwide retrospective cohort study

BACKGROUND

Whether laparoscopic pancreatoduodenectomy is a feasible treatment option equivalent to open pancreatoduodenectomy remains unclear. Using a nationwide inpatient database, we investigated the postoperative outcomes of laparoscopic pancreatoduodenectomy versus open pancreatoduodenectomy.

METHODS

We conducted a retrospective cohort study using a nationwide inpatient database in Japan. We included patients who underwent pancreatoduodenectomy from April 2016 to March 2018. One-to-four propensity score matching was used to compare in-hospital mortality, postoperative complications, perioperative findings, and total hospitalization costs between the 2 groups. We also compared outcomes between laparoscopic pancreatoduodenectomy and open pancreatoduodenectomy in low- and high-volume hospitals.

RESULTS

We identified 2,100 eligible patients. The laparoscopic pancreatoduodenectomy group contained higher proportions of younger patients and patients with fewer comorbidities compared with the open pancreatoduodenectomy group. Using propensity score matching, 95 patients in the laparoscopic pancreatoduodenectomy group were matched with 380 patients in the open pancreatoduodenectomy group. No significant differences in in-hospital mortality or postoperative complication rates were found between the groups. Compared with the open pancreatoduodenectomy group, the laparoscopic pancreatoduodenectomy group showed a longer duration of anesthesia (639 vs 497 minutes; P < .001), higher proportion of unplanned mechanical ventilation (10% vs 3%; P = .007), and higher total hospitalization costs (32,242 vs 24,657 US dollars; P < .001). The subgroup analyses showed that laparoscopic pancreatoduodenectomy was associated with a higher proportion of unplanned mechanical ventilation than open pancreatoduodenectomy but only in low-volume hospitals.

CONCLUSION

This study demonstrated almost no advantage of laparoscopic pancreatoduodenectomy over open pancreatoduodenectomy. Our results suggest that laparoscopic pancreatoduodenectomy can be an alternative option for open pancreatoduodenectomy only in high-volume hospitals.

Effect of Daikenchuto for Mechanically Ventilated Patients With Enteral Feeding Intolerance: A Propensity Score-Matched Analysis Using a Nationwide Administrative Inpatient Database

BACKGROUND

Daikenchuto, a Japanese herbal Kampo medicine, is used to improve gastrointestinal motility in critically ill patients with enteral feeding intolerance (EFI) in Japan. The present study aimed to investigate the effect of Daikenchuto for critically ill patients with EFI.

METHODS

Using the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2018, we identified mechanically ventilated patients in intensive care units (ICUs) who had EFI during mechanical ventilation. We defined EFI as receipt of intravenous metoclopramide during mechanical ventilation. Patients who started Daikenchuto within 2 days of EFI onset were defined as the Daikenchuto group, and the remaining patients were defined as the control group. Propensity score-matched analyses were performed to compare the outcomes between the 2 groups.

RESULTS

A total of 61,454 patients were included. Of these, 8842 patients (14%) were in the Daikenchuto group. One-to-one propensity score matching created 8701 matched pairs. After propensity score matching, the total number of days receiving enteral nutrition within 28 days of EFI onset was significantly longer in the Daikenchuto group than in the control group (risk difference, 0.9 days; 95% CI, 0.5-1.3 days). There were no significant differences in 28-day in-hospital mortality, hospital-acquired pneumonia, ventilator-free days, length of ICU stay, time to discharge alive, and adverse complications.

CONCLUSION

This nationwide observational study suggested that use of Daikenchuto may increase the total number of days receiving enteral nutrition in mechanically ventilated patients with EFI.

Safety and effectiveness of intracardiac echocardiography in ventricular tachycardia ablation: a nationwide observational study

Intracardiac echocardiography (ICE) utilized in conjunction with three-dimensional (3-D) mapping systems could enhance ventricular tachycardia (VT) ablation procedures. ICE has been increasingly used in VT ablation; however, the safety and effectiveness of VT ablation under the combined use of ICE remains unclear. The present study aimed to analyze the safety and short-term effects of VT ablation with or without ICE. We retrospectively enrolled patients who underwent initial VT ablation with a combination of ICE and a 3-D mapping system within 3 days of hospitalization and discharged from April 2011 to March 2017 using a nationwide Japanese inpatient database. Following enrollment, we conducted a propensity score-matching analysis to compare safety (in-hospital complications) and effectiveness (readmission within 30 days after discharge due to cardiovascular disease and readmissions within 30 days for repeat VT ablations) between patients who underwent VT ablation with (ICE group) and without ICE (non-ICE group). 3-D mapping systems were applied to both groups. We identified 5,804 eligible patients (1,272 and 4,532 patients in the ICE and non-ICE groups, respectively). One-to-one propensity score matching created a total of 1,147 pairs between the ICE and non-ICE groups. The ICE group showed a significantly lower prevalence of cardiac tamponade than the non-ICE group. There were no significant differences observed between the two groups regarding other outcomes concerning safety and effectiveness. Ventricular tachycardia ablation with ICE used in combination with a 3-D mapping system may reduce cardiac tamponade; however, no additional clinical advantages were noted in terms of safety and effectiveness.

Comparison of short-term surgical outcomes between men and women with breast cancer: a retrospective study using nationwide inpatient data in Japan

PURPOSE

Although long-term survival is similar between men and women, little is known about the short-term outcomes following breast cancer surgery in men. This study was performed to compare postoperative outcomes adjusted for background factors between men and women with breast cancer using a Japanese nationwide inpatient database.

METHODS

This study included 2126 men and 363,468 women who underwent surgery for stage 0-III breast cancer from July 2010 to March 2017. We generated a 1:4 matched-pair cohort matched for age, institution, and fiscal year at admission. We then conducted multivariable regression analyses to compare postoperative complications, 30-day readmission, duration of anesthesia, length of hospitalization, and total hospitalization costs between the sexes.

RESULTS

Men were older, more likely to have comorbidities and advanced cancer, and more likely to undergo total mastectomy and axillary dissection than women. There were no significant differences in postoperative complications between the sexes, but men showed a lower risk of 30-day readmission (odds ratio 0.74; 95% confidence interval [CI] 0.57-0.95), shorter duration of anesthesia (difference - 22.0 min; 95% CI - 2.1 to - 0.5), shorter length of hospitalization (difference - 1.3 days; 95% CI - 2.1 to - 0.5), and lower total hospitalization costs (difference - 506 US dollars; 95% CI - 668 to - 334) than women.

CONCLUSIONS

The matched-pair cohort analyses revealed no significant differences in postoperative complications between men and women with breast cancer. However, men showed better outcomes than women in terms of 30-day readmission, duration of anesthesia, length of hospitalization, and total hospitalization costs.

Epidemiology of Chronic Critical Illness in Japan: A Nationwide Inpatient Database Study

OBJECTIVES

The epidemiology of chronic critical illness is not well known. We aimed to estimate the prevalence, mortality, and costs associated with chronic critical illness in Japan.

DESIGN

A nationwide inpatient administrative database study in Japan from April 2011 to March 2018.

SETTING

Six hundred seventy-nine acute-care hospitals with ICU beds in Japan.

PATIENTS

Adult patients who met our definition for chronic critical illness: one of six eligible clinical conditions (prolonged acute mechanical ventilation, tracheotomy, stroke, traumatic brain injury, sepsis, and severe wound) plus at least 8 consecutive days in an ICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among 2,395,016 ICU admissions during the study period, 216,434 (9.0%) met the definition for chronic critical illness. The most common eligible condition was prolonged acute mechanical ventilation (73.9%), followed by sepsis (50.6%), tracheostomy (23.8%), and stroke (22.8%). Overall inhospital mortality was 28.6%. The overall age-specific population prevalence was 42.0 per 100,000. The age-specific population prevalence steadily increased with age, reaching 109.6 per 100,000 in persons aged greater than 85 years. With extrapolation to national estimates in Japan, there were 47,729 chronic critical illness cases in 2011 and the number remained similar at 46,494 cases in 2017. Hospitalization costs increased gradually, rising from U.S.$2.3 billion in 2011 to U.S.$2.7 billion in 2017. Inhospital mortality decreased from 30.6% to 28.2%, whereas the proportion of patients with total/severe dependence increased from 29.6% to 33.2% and the proportion of patients with decreased consciousness at discharge increased from 18.7% to 19.6%.

CONCLUSIONS

Using a nationwide inpatient database in Japan, we found substantial clinical and economic burdens of chronic critical illness in Japan. Chronic critical illness was particularly common in elderly people. Although inhospital mortality of chronic critical illness patients continues to decrease, costs and patients with dependence for activities of daily living or decreased consciousness at discharge are increasing.

Development and validation of a procedure-based organ failure assessment model for patients in the intensive care unit: an administrative database study

Aim

To develop a procedure‐based organ failure assessment model for intensive care unit (ICU) patients and to examine the ability of this model to predict in‐hospital mortality, with reference to the Sequential Organ Failure Assessment (SOFA) score.

Methods

Using the Japanese nationwide Diagnosis Procedure Combination database, we identified patients aged ≥15 years who were admitted to the ICUs April 2018–March 2019. Since April 2018, Japanese health care providers have been required to input ICU patients' SOFA scores into this database. We extracted data on the following procedures on ICU admission: oxygen supplementation, invasive mechanical ventilation, blood transfusions, catecholamines, chest compression, extracorporeal membrane oxygenation, and renal replacement therapy. A procedure‐based organ failure assessment model (Model 1) for in‐hospital mortality was developed using therapeutic procedures for organ failure on the day of ICU admission in the derivation cohort. We also constructed a model using the SOFA score (Model 2). Discriminatory ability was assessed using area under the receiver operating characteristic curve (AUROC) in the validation cohort, and the discriminatory abilities of the models were compared.

Results

In total, 69,019 patients were included. Overall in‐hospital mortality was 7.2%. The AUROCs for Model 1 (0.810) and Model 2 (0.817) in the validation cohort did not show a statistically significant difference (P = 0.20).

Conclusion

The models established using procedure‐based organ failure assessment showed no statistically significant differences from those using the SOFA score, suggesting that procedure records in administrative databases can be used for risk adjustment in clinical studies on ICU mortality.

Current trends and outcomes of extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest in Japan: A nationwide observational study

AIM

The present study aimed to describe the prevalence, prognosis and annual trends of extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA) patients, using a nationwide inpatient database in Japan.

METHODS

This was a nationwide retrospective cohort study, using the Japanese Diagnosis Procedure Combination inpatient database. We included OHCA patients registered in the database from July 2010 to March 2017 and analyzed the annual prevalence of OHCA patients who received ECPR. The outcomes included survival to hospital discharge and survival with favorable neurologic outcome at hospital discharge. The annual trends on the outcomes were also analyzed.

RESULTS

We identified 217,907 eligible patients. OHCA patients were divided into patients with ECPR (n = 5,612) and conventional CPR (n = 212,295). The prevalence of ECPR performed in OHCA patients was 2.6%. ECPR prevalence significantly increased from 2.1% in 2010 to 3.0% in 2016 (P < 0.001). Overall survival to hospital discharge was 16.4% and 2.7% in patients with ECPR and conventional CPR, respectively. Prevalence of patients who were discharged from hospital with favorable neurologic outcome was 12.4% and 1.6% in those with ECPR and conventional CPR, respectively.Increasing age was associated with progressively deteriorating outcomes. The trend of survival to hospital discharge significantly increased on an annual basis.

CONCLUSIONS

The annual prevalence of ECPR significantly increased from 2010 to 2016. Improvements in overall survival to hospital discharge were noted for ECPR in OHCA patients and there was a trend in the tendency for ECPR patients discharged from the hospital to have favorable neurologic outcomes.

Association between body mass index and localization of breast cancer: results from a nationwide inpatient database in Japan

PURPOSE

Although both localization of breast cancer and body mass index (BMI) are associated with prognosis, the association between localization of breast cancer and BMI remains unclear. This study aimed to investigate the association between localization of breast cancer and BMI at diagnosis.

METHODS

Patients who underwent surgery for stage 0-III breast cancer July 2010-March 2017 were identified retrospectively in a Japanese nationwide inpatient database. Multinomial logistic regression analyses adjusting for patient's age were conducted to compare the outcomes among five BMI groups: < 18.5 kg/m² (n = 31,724; 9.3%), 18.5-24.9 kg/m² (n = 218,244; 64.3%), 25.0-29.9 kg/m² (n = 69,813; 20.6%), 30.0-34.9 kg/m² (n = 16,052; 4.7%), and ≥ 35.0 kg/m² (n = 3716; 1.1%). The outcomes were the quadrant and side of the breast where tumors were detected.

RESULTS

In total, about half of the patients had breast cancer in the upper-outer quadrant (49.7%) and in the left breast (51.1%). In the multinomial analysis, BMI ≥ 25.0 kg/m² was associated with the occurrence of breast cancer in the upper-inner and lower-outer quadrants and in the central area, whereas BMI < 18.5 kg/m² was associated with the occurrence of breast cancer in the central area only. The side of breast cancer did not differ significantly among the five BMI groups.

CONCLUSIONS

Localization of breast cancer was associated with BMI in this large nationwide cohort. The findings may benefit patients' self-checks and doctors' examinations, potentially resulting in early detection and treatment.

Antithrombin use and mortality in patients with stage IV solid tumor-associated disseminated intravascular coagulation: a nationwide observational study in Japan

Background

Terminal-stage solid tumors are one of the main causes of disseminated intravascular coagulation (DIC); effective therapeutic strategies are therefore warranted. This study aimed to investigate the association between mortality and antithrombin therapy in patients with stage IV solid tumor-associated DIC using a large nationwide inpatient database.

Methods

From July 2010 to March 2018, patients with stage IV solid tumor-associated DIC in the general wards, intensive care unit, or high care unit were identified using the Japanese Diagnosis Procedure Combination Inpatient Database. Patients who received antithrombin within 3 days of admission were allocated to the antithrombin group, while the remaining patients were allocated to the control group. One-to-four propensity score matching analyses were applied to compare outcomes. The primary outcome was the 28-day in-hospital mortality.

Results

Of the 25,299 eligible patients, 919 patients had received antithrombin within 3 days of admission and were matched with 3676 patients in the control group. There were no significant differences in the 28-day mortality between the two groups (control vs. antithrombin: 28.9% vs. 30.3%; hazard ratio, 1.08; 95% confidence interval, 0.95–1.23). There were no significant differences in the organ failure score and the proportion of critical bleeding between the two groups. Subgroup analyses showed that the effects of antithrombin were not significantly different among different tumor types.

Conclusion

Using a nationwide Japanese inpatient database, this study showed that there is no association between antithrombin administration and 28-day mortality in patients with stage IV solid tumor-associated DIC. Therefore, establishing other therapeutic strategies for solid tumor-associated DIC is required.

Recombinant Thrombomodulin in Disseminated Intravascular Coagulation Associated with Stage IV Solid Tumors: A Nationwide Observational Study in Japan

OBJECTIVE

 The terminal stage of solid tumors sometimes induces disseminated intravascular coagulation (DIC); however, no useful therapeutic strategies have been established. This study investigated the relationship between mortality and recombinant human soluble thrombomodulin (rTM) therapy for patients with DIC associated with stage IV solid tumors using a large nationwide inpatient database.

METHODS

 Using the Japanese Diagnosis Procedure Combination Inpatient Database, patients with stage IV solid tumors who developed DIC were identified. Those who received rTM within 3 days of admission were included in the treatment group; the remaining were included in the control group. The primary outcome was the 28-day in-hospital mortality.

RESULTS

 Of 25,299 eligible patients, 1 to 4 propensity score matching was used to select 1,979 rTM users and 7,916 nonusers. There was no significant difference in the 28-day mortality (control vs. rTM: 37.4% vs. 34.3%; hazard ratio, 0.95; 95% confidence interval [CI], 0.88-1.04) and critical bleeding rate (control vs. rTM: 3.7% vs. 3.8%; odds ratio, 1.04; 95% CI, 0.75-1.42) between groups. Subgroup analyses showed that the 28-day mortality rate among patients with colorectal and gynecological cancer was significantly lower in the rTM than in the control group (p for interaction 0.033 and 0.010, respectively).

CONCLUSION

 Although we identified a possibly beneficial association between rTM administration and mortality in specific populations of patients with colorectal and gynecological cancer, no such association was found when considering the entire cohort of patients with DIC associated with stage IV solid tumors.

Association Between IV Thiamine and Mortality in Patients With Septic Shock: A Nationwide Observational Study

OBJECTIVES

To examine the effect of thiamine administration on mortality in patients with septic shock requiring norepinephrine.

DESIGN

Retrospective observational cohort study from July 2010 to March 2017.

SETTING

More than 1,000 acute care hospitals covering approximately 90% of all tertiary care emergency hospitals in Japan.

PATIENTS

Patients with septic shock requiring norepinephrine within 2 days of admission were retrospectively reviewed.

INTERVENTIONS

Patients who received greater than or equal to 100 mg of thiamine within 2 days of admission were included in the thiamine group and those who did not were included in the control group.

MEASUREMENTS AND MAIN RESULTS

We identified a total of 68,571 eligible patients, including 18,780 and 49,791 patients in the thiamine and control groups, respectively. In the thiamine group, 100 and 200 mg of thiamine per day were administered to 10,143 (54.0%) and 7,679 (40.9%) patients, respectively. The 28-day mortality were 19.2% (3,609/18,780) and 17.8% (8,845/49,791) in the thiamine and control groups, respectively. After adjusting for confounders by inverse probability of treatment weighting, no significant differences were observed between the two groups (risk difference, 0.2%; 95% CI, -0.5% to 0.9%). There were also no significant differences between the 100-mg thiamine group and the control group (risk difference, 0.6%; 95% CI, -0.3% to 1.4%) or between the 200-mg thiamine group and the control group (risk difference, -0.3%; 95% CI, -1.3% to 0.8%).

CONCLUSIONS

The findings of this nationwide database-based observational study did not support an association between thiamine administration early after admission and the 28-day mortality in patients with septic shock.

Levetiracetam vs. Fosphenytoin for Second-Line Treatment of Status Epilepticus: Propensity Score Matching Analysis Using a Nationwide Inpatient Database

Objective: Status epilepticus is a major emergency condition. The choice of antiepileptic drugs for second-line treatment after benzodiazepine remains controversial, including levetiracetam vs. fosphenytoin. We compare the safety of intravenous levetiracetam and fosphenytoin as a second-line treatment in patients with status epilepticus using a nationwide database.

Methods: An observational study conducted with the Japanese Diagnosis Procedure Combination inpatient database identified adult patients who had been admitted for status epilepticus and who had received intravenous diazepam on the day of admission from March 1, 2011 to March 31, 2018. Patients who received intravenous levetiracetam on the day of admission were defined as the levetiracetam group and those who received intravenous fosphenytoin on the day of admission were defined as the fosphenytoin group. Propensity score matching was performed to compare outcomes obtained for the levetiracetam and fosphenytoin groups.

Results: The analysis examined data of 5,667 patients. Overall, 1,403 (25%) patients received levetiracetam; 4,264 (75%) received fosphenytoin. One-to-one propensity score matching created 1,363 matched pairs. No significant difference was found in in-hospital mortality (5.2 vs. 5.1%; odds ratio, 1.03; 95% confidence interval, 0.73–1.46). The proportion of vasopressor use on the day of admission was significantly lower for the levetiracetam group than for the fosphenytoin group (3.2 vs. 4.9%; odds ratio, 0.63; 95% confidence interval, 0.43–0.92). No significant difference was found in other secondary outcomes including total hospitalization cost.

Conclusion: Levetiracetam was related to significantly reduced vasopressor use on the day of admission than that found for fosphenytoin, in adult status epilepticus.

Impact of Body Mass Index on Outcomes After Breast Cancer Surgery: Nationwide Inpatient Database Study in Japan

BACKGROUND

Recent studies have shown better postoperative outcomes in mildly obese patients, a phenomenon called the obesity paradox. In the field of breast cancer surgery, however, previous studies have only shown an association between obesity and worse postoperative outcomes using multivariable analysis; the obesity paradox has not been investigated in patients undergoing breast cancer surgery.

PATIENTS AND METHODS

We identified patients who underwent mastectomy for stage 0 to III breast cancer from July 2010 to March 2017 using a Japanese nationwide inpatient database. We used restricted cubic spline analyses to investigate potential nonlinear associations between body mass index (BMI) and outcomes (postoperative complications, 30-day readmission, duration of anesthesia, length of hospital stay, and hospitalization costs). We also performed multivariable regression analyses for the outcomes.

RESULTS

Among 239,108 eligible patients, 25.6% had a BMI of > 25.0 kg/m². BMI showed U-shaped associations with postoperative complications, length of stay, and hospitalization costs, and a linear association with duration of anesthesia. The proportion of postoperative complications was lowest at a BMI of around 22.0 kg/m², while the length of stay was shortest and total costs were lowest at a BMI of around 20.0 kg/m². Compared to a BMI of 22.0 kg/m², a BMI of > 30.0 kg/m² was significantly associated with greater postoperative complications, 30-day readmission, duration of anesthesia, length of stay, and hospitalization costs.

CONCLUSION

Restricted cubic spline analyses displayed U-shaped associations between BMI and in-hospital complications, length of stay, and hospitalization costs, but none of the associations showed the obesity paradox.