Impact of a board certification system and adherence to the clinical practice guidelines for gastric cancer on risk-adjusted surgical mortality after distal and total gastrectomy in Japan: a questionnaire survey of departments registered in the National Clinical Database.

PURPOSE: The relationship between board certification, clinical guideline implementation, and quality of gastric cancer surgery remains unclear. METHODS: A web-based questionnaire survey was administered to departments registered in the National Clinical Database (NCD) of Japan between October 2014 and January 2015. Quality indicators (QIs) based on the Donabedian model were evaluated. Structural QIs (e.g., affiliations with academic societies and board certifications) and process QIs (adherence to clinical practice guidelines for gastric cancer) were assessed using risk-adjusted odds ratios (AORs) for surgical mortality. Multivariable logistic regression models with a generalized estimating equation were used. RESULTS: A total of 835 departments performing 40,992 distal gastrectomies and 806 departments performing 19,618 total gastrectomies responded. Some certified institutions and physicians showed significant associations, with lower AORs for surgical mortality. Important process QIs included pre- and postoperative abdominal CT scanning, endoscopic resection based on progression, curative resection with D2 dissection for advanced gastric cancer, laparoscopic surgery, and HER2 testing for patients with unresectable recurrent gastric cancer. CONCLUSIONS: Multiple structural and process QIs are associated with surgical mortality after gastrectomy in Japan. Measuring and visualizing QIs may enhance healthcare improvements.

Annual report on National Clinical Database 2020 for gastroenterological surgery in Japan.

Aim: The National Clinical Database (NCD) of Japan is a nationwide data entry system for surgery, and it marked its 10th anniversary in 2020. The aim was to present the 2020 annual report of gastroenterological surgery of the NCD. Methods: The data of the surgical procedures stipulated by the training curriculum for board-certified surgeons of the Japanese Society of Gastroenterological Surgery in the NCD from 2011 to 2020 were summarized. Results: In total, 5 622 845 cases, including 593 088 cases in 2020, were extracted from the NCD. The total number of gastroenterological surgeries increased gradually in these 10 years, except for the year 2020 due to the COVID-19 pandemic. The annual number of surgeries of each organ, except the pancreas and liver, decreased by 0.4%-13.1% in 2020 compared to 2019. The surgical patients were consistently aging, with more than 20% of all gastroenterological surgeries in 2020 involving patients aged 80 years or older. The participation of board-certified surgeons increased for each organ (75.9%-95.7% in 2020). The rates of endoscopic surgery also increased constantly. Although the incidences of postoperative complications of each organ increased by 0.7%-7.9% in these 10 years, postoperative mortality rates decreased by 0.2%-1.5%. Conclusions: We present here the short-term outcomes of each gastroenterological operative procedure in 2020. This review of the 10-years of NCD data of gastroenterological surgery revealed a consistent increase of the number of surgeries (except for in 2020), especially endoscopic procedures, and aging of the Japanese population. The good safety of Japanese gastroenterological surgeries was also indicated.

Achieving clinically optimal balance between accuracy and simplicity of a formula for manual use: Development of a simple formula for estimating liver graft weight with donor anthropometrics.

In developing a formula for manual use in clinical settings, simplicity is as important as accuracy. Whole-liver (WL) mass is often estimated using demographic and anthropometric information to calculate the standard liver volume or recommended graft volume in liver transplantation. Multiple formulas for estimating WL mass have been reported, including those with multiple independent variables. However, it is unknown whether multivariable models lead to clinically meaningful improvements in accuracy over univariable models. Our goal was to quantitatively define clinically meaningful improvements in accuracy, which justifies an additional independent variable, and to identify an estimation formula for WL graft weight that best balances accuracy and simplicity given the criterion. From the Japanese Liver Transplantation Society registry, which contains data on all liver transplant cases in Japan, 129 WL donor-graft pairs were extracted. Among the candidate models, those with the smallest cross-validation (CV) root-mean-square error (RMSE) were selected, penalizing model complexity by requiring more complex models to yield a ≥5% decrease in CV RMSE. The winning model by voting with random subsets was fitted to the entire dataset to obtain the final formula. External validity was assessed using CV. A simple univariable linear regression formula using body weight (BW) was obtained as follows: WL graft weight [g] = 14.8 × BW [kg] + 439.2. The CV RMSE (g) and coefficient of determination (R2) were 195.2 and 0.548, respectively. In summary, in the development of a simple formula for manually estimating WL weight using demographic and anthropometric variables, a clinically acceptable trade-off between accuracy and simplicity was quantitatively defined, and the best model was selected using this criterion. A univariable linear model using BW achieved a clinically optimal balance between simplicity and accuracy, while one using body surface area performed similarly.

Cost of postoperative complications of lower anterior resection for rectal cancer: a nationwide registry study of 15,187 patients.

PURPOSE: To assess the increase in hospital costs associated with postoperative complications after lower anterior resection (LAR) for rectal cancer. METHODS: The subjects of this retrospective analysis were patients who underwent elective LAR surgery between April, 2015 and March, 2017, collected from a Japanese nationwide gastroenterological surgery registry linked to hospital-based claims data. We evaluated total and category-specific hospitalization costs based on the level of postoperative complications categorized using the Clavien-Dindo (CD) classification. We assessed the relative increase in hospital costs, adjusting for preoperative factors and hospital case volume. RESULTS: We identified 15,187 patients (mean age 66.8) treated at 884 hospitals. Overall, 71.8% had no recorded complications, whereas 7.6%, 10.8%, 9.0%, 0.6%, and 0.2% had postoperative complications of CD grades I-V, respectively. The median (25th-75th percentiles) hospital costs were $17.3 K (16.1-19.3) for the no-complications group, and $19.1 K (17.3-22.2), $21.0 K (18.5-25.0), $27.4 K (22.4-33.9), $41.8 K (291-618), and $22.7 K (183-421) for the CD grades I-V complication groups, respectively. The multivariable model identified that complications of CD grades I-V were associated with 11%, 21%, 61%, 142%, and 70% increases in in-hospital costs compared with no complications. CONCLUSIONS: Postoperative complications and their severity are strongly associated with increased hospital costs and health-care resource utilization. Implementing strategies to prevent postoperative complications will improve patients' clinical outcomes and reduce hospital care costs substantially.

Geriatric Risk Prediction Models for Major Gastroenterological Surgery Using the National Clinical Database in Japan: A Multicenter Prospective Cohort Study.

OBJECTIVES: To investigate the effect of geriatric variables on 5 newly added outcomes and create risk models for predicting these outcomes. SUMMARY OF BACKGROUND DATA: Because there is a current lack of geriatric research focusing on geriatric outcomes using a national surgical database in Japan, there is a need to investigate outcomes associated with major gastro-enterological surgery using these data. METHODS: This multicenter prospective cohort study was conducted at 26 surgery departments across 21 institutions in Japan using the NCD surgical registry. in total, 22 new geriatric variables were imported from the ACS National Surgical Quality Improvement Program geriatric pilot study. The following 5 geriatric outcomes were defined: (1) postoperative delirium, (2) physical function on postoperative day 30, (3) fall risk on discharge, (4) discharge other than home with social service, and (5) functional decline on discharge, and geriatric risk prediction models for major gastroenterological surgery were created. RESULTS: Between January 2018 and December 2018, data on 3981 procedures from 7 major gastroenterological surgeries were collected and analyzed. Older age and preoperative geriatric variables (Origin status from home, History of dementia, Use of mobility aid, fall history, and not competent on admission) were strongly associated with postoperative outcomes. Geriatric risk prediction models for these outcomes were created, with C-statistic values ranging from 0.74 to 0.90, demonstrating model validity and sufficiency of fit. CONCLUSIONS: The risk models for the newly defined 5 geriatric outcomes that we created can be used in the decision-making process or provision of care in geriatric patients.

Surgical outcomes in gastroenterological surgery in Japan: Report of the National Clinical Database 2011-2019.

BACKGROUND: We aimed to present the 2019 annual report of the gastroenterological section of the National Clinical Database (NCD). METHODS: We reviewed 609,589 cases recorded in 2019 and 5,029,764 cases registered from 2011 to 2019 for the 115 selected gastroenterological surgical procedures. RESULTS: The main features of gastroenterological surgery in Japan were similar to those described in the 2018 annual report, namely, that 1) operative numbers gradually increased in all procedures, except gastrectomy and hepatectomy, which decreased in these years; 2) in all eight major gastroenterological surgeries, the age distribution tended toward older patients; 3) the morbidity of esophagectomy, hepatectomy, and pancreaticoduodenectomy increased, but mortality was minimized in all procedures; 4) all eight major gastroenterological procedures have increasingly been performed under laparoscopy; and 5) board-certified surgeons were increasingly involved. These trends in recent years were more prominent in 2019. CONCLUSIONS: Thanks to the continuous cooperation and dedication of the surgeons, medical staff, and surgical clinical reviewers who registered the clinical data into the NCD, it is possible to understand the comprehensive landscape of surgery in Japan and to disclose new evidence in this field. The Japanese Society of Gastroenterological Surgery will continue to promote the value of this database and encourage the use of feedback and clinical studies using the NCD, now and in the future. Generating further approaches to surgical quality improvement are important directions for future research.

Validation of data quality in a nationwide gastroenterological surgical database: The National Clinical Database site-visit and remote audits, 2016-2018.

BACKGROUND AND AIM: In 2015, the Japanese Society of Gastroenterological Surgery (JSGS) initiated data verification in the gastroenterological section of the National Clinical Database (NCD) and reported high accuracy of data entry. Remote audits were introduced for data validation on a trial basis in 2016 and formally accepted into use in 2017-2018. The aim of this study was to audit the data quality of the NCD gastroenterological section for 2016-2018 and to confirm the high accuracy of data in remote audits. METHODS: Each year, 45-46 hospitals were selected for audit. Twenty cases were randomly selected in each hospital, and the accuracy of patient demographic and surgical outcome data (46 items) was compared with the corresponding medical records obtained by visiting the hospital (site-visit audit) or by mailing data from the hospital to the JSGS office (remote audit). RESULTS: A total of 136 hospitals were included, of which 88 (64.7%) had a remote audit, and 124 936 items were evaluated with an overall data accuracy of 98.1%. There was no significant difference in terms of data accuracy between site-visit audit and remote audit. Accuracy, sensitivity, and specificity of mortality were 99.7%, 89.7%, 100% for site-visit audits and 99.8%, 97.3%, 100% for remote audits, respectively. Mean time spent on data verification per case of remote audits was shorter than that of site-visit audits (10.0 minutes vs 13.7 minutes, P < 0.001). CONCLUSION: The audits showed that NCD data are reliable and characterized by high accuracy. Remote audits may substitute site-visit audits.

Validation study of the ACS NSQIP surgical risk calculator for two procedures in Japan.

INTRODUCTION: The ACS NSQIP Surgical Risk Calculator (SRC) assesses risk to support goal-concordant care. While it accurately predicts US outcomes, its performance internationally is unknown. This study evaluates SRC accuracy in predicting mortality following low anterior resection (LAR) and pancreaticoduodenectomy (PD) in NSQIP patients and accuracy retention when applied to native Japanese patients (National Clinical Database, NCD). METHODS: NSQIP (41,260 LAR; 15,114 PD) and NCD cases (61,220 LAR; 27,901 PD) from 2015 to 2017 were processed through the SRC mortality model. Country-specific calibration and discrimination were assessed with and without an intercept correction applied to the Japanese data. RESULTS: The SRC exhibited acceptable calibration for LAR and PD when applied to NSQIP data but miscalibration for NCD data. A simple correction to the model intercept, motivated by lower mortality rates in the Japanese data, successfully remediated the miscalibration. CONCLUSIONS: The SRC may inaccurately predict surgical risk when applied to the native Japanese population. An intercept correction method is suggested when miscalibration is encountered; it is simple to implement and may permit effective international use of the SRC.

Impact of board certification system and adherence to the clinical practice guidelines for liver cancer on post-hepatectomy risk-adjusted mortality rate in Japan: A questionnaire survey of departments registered with the National Clinical Database.

BACKGROUND: It is unclear to what extent a board certification system and implementation of clinical guidelines improves the quality of hepatectomy. METHODS: A web-based questionnaire survey was administered to departments registered with the National Clinical Database (NCD) in Japan between 1 October 2014 and 31 January 2015. Quality indicators (QIs), including affiliations with academic societies, numbers of board-certified doctors affiliated with each institute, and adherence to clinical practice guidelines for hepatocellular carcinoma, were evaluated by calculating risk-adjusted odds ratios (AORs) for 90-day postoperative mortality of patients who had undergone hepatectomy in 2013 and 2014. RESULTS: Of 1255 departments that had registered at least one hepatectomy in NCD, 592 departments, performing 8601 hepatectomies in total, responded to the questionnaire. AORs were significantly lower in departments that were certified as training hospitals by the Japanese Society of Gastroenterological Society, Japanese Society of Hepato-Biliary-Pancreatic Surgery (JSHBPS), and Japan Society of Hepatology than in non-certified departments. Affiliation of three or more JSHBPS-certified experts or instructors with an institution also contributed to low AORs. None of the QIs regarding implementation of guidelines significantly impacted on the AOR. CONCLUSIONS: Quality indicator measurements may improve quality of post-hepatectomy outcomes in Japan.

Estimates of the effects of centralization policy for surgery in Japan: does centralization affect the quality of healthcare for esophagectomies?

PURPOSE: This study compared the quality of healthcare before and after implementation of a policy restructuring the healthcare delivery system and estimated the impact of centralization. METHODS: We used the National Clinical Database to study patients undergoing esophagectomies from 2011 to 2016. We compared the effect of centralization based on the patient background, surgical mortality, and year of surgery. Difference-in-difference methods based on the generalized estimating equation logistic regression model were used for before-and-after comparisons after adjusting for patient-level expected surgical mortality. RESULTS: In total, 34,640 cases were identified. More cases with risk factors were noted in ultra-low-volume hospitals, where 38.4% of cases in underpopulated areas were treated, than in higher volume facilities, and the operative mortality, readmission within 30 days and length of stay were worse among patients treated in these hospitals. In centralized prefectures, the number of cases per hospital increased over time (7.2 in 2011 to 9.5 in 2016) while the crude operative mortality tended to decrease (3.4% in 2011 to 1.8% in 2016). The difference-in-difference estimator was 0.856 (95% confidence interval: 0.639-1.147, p = 0.298). CONCLUSION: The centralization of ultra-low-volume hospitals did not lead to a deterioration in the quality of care but rather an improving trend.

Comprehensive analysis of gene expression of isolated pancreatic islets during pretransplant culture.

BACKGROUND: The aim of this study was to investigate the effect of pretransplant culture on the survival of pancreatic islet grafts, and to determine the biological characteristics of isolated islets during pretransplant culture. METHODS: The survival of islets from Wistar rats, transplanted to diabetic C57BL/B6 mice, was compared between fresh islets and cultured islets. A comprehensive gene expression analysis was employed to investigate biological processes during pretransplant culture, and in vitro validation studies were performed. RESULTS: Survival of cultured xenografts was significantly prolonged as compared to that of fresh islets (fresh:12.5 ± 1.9 days, 1-day cultured:16.0 ± 1.3 days (p= 0.017), 3-day cultured:17.0 ± 2.6 days (p= 0.014)). Comprehensive gene expression analysis identified significant upregulation of annotated functions associated with inflammation in cultured groups. Six proinflammatory genes, including heme oxygenase 1 (HO-1) and IL-6, were significantly upregulated during culture.　Validation studies revealed significantly higher levels of IL-6 in the supernatant of cultured islets and HO-1 in the cultured islets when compared with fresh islets. CONCLUSION: Transplantation of cultured islets induced significant but minimal prolongation of graft survival in xenogeneic combinations. Comprehensive analysis of gene expression in cultured islets showed biological processes associated with proinflammation during culture.

[A Case of Squamous Cell Cancer of the Anus Treated with Chemoradiotherapy].

BACKGROUND: In Japan, the standard treatment for squamous cell anal cancer(SCAC)has not been established. Herein, we report a case of SCAC that completely responded to chemoradiotherapy(CRT). CASE: A woman in her 80s presented with anal pain and bleeding. Computed tomography revealed bilateral inguinal adenopathy and a tumor in the anal canal. Histopathological examination of endoscopic biopsies showed adenocarcinoma. Thus, she was diagnosed with anal canal adenocarcinoma and lymph node metastases:cT3, cN1a(No. 292), cM0, cStage Ⅲc(Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma, 9th edition). Owing to her advanced age and refusal of a stoma, CRT(S-1, mitomycin C, and radiotherapy)was administered with the expectation that salvage surgery in the form of rectal amputation would eventually be necessary. The tumor noticeably shrank after CRT. The patient is alive to this date,14 months after the final round of CRT.

[Robotic Surgery Can Complete Radical Surgery and Urinary Tract Reconstruction for Locally Advanced Rectal Cancer with Ureteral Invasion-A Case Report].

A 82-year-old man presented with diarrhea and fatigue. He had no past medical or surgical history except chronic renal failure. Locally advanced rectal cancer with invasion to left ureter was detected in computed tomography. Colonoscopy revealed a circular lesion 12 cm from the anal verge. Biopsy showed moderately differentiated adenocarcinoma. There was no sign of distal metastasis and we decided to conduct radical surgery. Robot-assisted laparoscopic lower anterior resection with partial resection of left ureter, and diverting ileostomy were carried out. Besides, urinary tract reconstruction of ureterocystoneostomy using Lich-Gregoir technique was conducted by urologists also with robot assistance. The pathological stage of the disease was pT4b(left ureter)N1bM0, pStage Ⅲc. The resection margin was secured and radical surgery was achieved. The patient was discharged on postoperative day 22nd without postoperative complication. He is alive without recurrence at 6 months after the operation.

Development of gastroenterological surgery over the last decade in Japan: analysis of the National Clinical Database.

The National Clinical Database (NCD) of Japan was established in 2010 with the board certification system. A joint committee of 16 gastroenterological surgery database-affiliated organizations has been nurturing this nationwide database and utilizing its data for various analyses. Stepwise board certification systems have been validated by the NCD and are used to improve the surgical outcomes of patients. The use of risk calculators based on risk models can be particularly helpful for establishing appropriate and less invasive surgical treatments for individual patients. Data obtained from the NCD reflect current developments in the surgical approaches used in hospitals, which have progressed from open surgery to endoscopic and robot-assisted procedures. An investigation of the data acquired by the NCD could answer some relevant clinical questions and lead to better surgical management of patients. Furthermore, excellent surgical outcomes can be achieved through international comparisons of the national databases worldwide. This review examines what we have learned from the NCD of gastroenterological surgery and discusses what future developments we can expect.

Impact of donor and prolonged cold ischemia time of neonatal pig pancreas on neonatal pig islet transplant outcome.

BACKGROUND: Genetically modified pigs (GMP) have been developed to alleviate the shortage of donors in human islet transplantation and rejection. In this study, we characterized and compared the islets from GalTKO, GalTKO/hCD46, GalTKO/hCD46/hCD39, and wild-type (WT) neonatal pigs. METHODS: Islets were isolated from GMP and WT pig pancreases that have been packaged with ice pack for at least 24 hours. The difference in gene expression and function of islets were evaluated by microarray analysis and transplantation of islets under the kidney capsule of streptozotocin-induced diabetic immune-deficient mice, respectively. Blood glucose levels of these mice were monitored weekly post-transplantation for >100 days, and islet grafts were collected and evaluated for the presence of endocrine cells. RESULTS: The genes involved in extracellular components, cell adhesion, glucose metabolism, and inflammatory response are differentially expressed between GMP and WT pig islets. Variation in the ability of pig islets in correcting the diabetic state of the mouse recipients appears to be dependent on the pig donor. In addition, prolonged cold ischemia time had a negative effect on the transplant outcome. All normoglycemic mice were able to respond well to glucose challenge despite the initial differences in the ability of islet transplants to reverse their diabetic state. Islet xenografts of normoglycemic mice contained abundant insulin- and glucagon-positive cells. CONCLUSION: The effect of GMP and WT neonatal pig islet transplants on hyperglycemia in mice appears to be dependent on the pig donor, and prolonged cold ischemia time negatively affects the neonatal pig islet transplant outcome.

Surgical outcomes in gastroenterological surgery in Japan: Report of the National Clinical Database 2011-2018.

The National Clinical Database (NCD) of Japan grew rapidly, harvesting over 11 million cases of data between 2011 and 2018 from more than 5000 facilities. This is the Report of the NCD based upon gastrointestinal surgery information in 4 420 175 cases from 2011 to 2018. More than 70% of all gastrointestinal surgeries were performed at certified institutions, and the percentage of surgeries performed at certified institutions was particularly high for the esophagus (93.8% in 2018), liver (89.4%), pancreas (91.3%), and spleen (86.9%). Also, more than 70% of the surgeries were performed with the participation of the board-certified surgeon. As the patients have been getting older, the morbidities have been increasing. However, the mortalities have been kept at a low level. The rates of endoscopic surgery have been increasing year by year, especially high in low anterior resection (67.0%) and esophagectomy (61.0%). Nationwide, this database is surely expecting to ensure the quality of board certification system and surgical outcomes in gastroenterological surgery.

Impact of adherence to board-certified surgeon systems and clinical practice guidelines on colon cancer surgical outcomes in Japan: A questionnaire survey of the National Clinical Database.

AIM: To investigate the effectiveness of the institutional medical structure and of the implemented clinical practice guidelines for improving colon cancer surgical outcomes. METHODS: We conducted a web-based questionnaire survey among departments registered at the National Clinical Database in Japan from October 2014 to January 2015 to assess the association between quality indicators (QIs), including structure and process indicators (clinical practice guideline adherence), and the risk-adjusted odds ratio for operative mortality (AOR) after right hemicolectomy for colorectal cancer during the study period. RESULTS: Among the 2064 departments registering at least one colorectal surgery during the study period, we obtained responses from 814 departments (39.4%). Our analysis on data from 22 816 patients with right hemicolectomy demonstrated that three structural QIs (certification of training hospitals by the Japanese Society of Gastroenterological Surgery and the presences of board-certified gastroenterological and colorectal surgeons) were associated with significantly lower AOR (P < .001, P = .02, and P = .05, respectively). The "performed at the doctor's discretion" answer was associated with poorer short-term outcomes in six process QIs than other answers. CONCLUSION: The board certification system for gastroenterological and colorectal surgeons and the adherence to the clinical guidelines improve the operative mortality after right hemicolectomy. It is desired to clarify the most suitable QIs to reduce the operative mortality after colorectal surgery.

Impact of a board certification system and implementation of clinical practice guidelines for pancreatic cancer on mortality of pancreaticoduodenectomy.

PURPOSES: The aim of this study was to clarify the impact of a board certification system and the implementation of clinical practice guidelines for pancreatic cancer (PC) on the mortality of pancreaticoduodenectomy in Japan. METHODS: By a web questionnaire survey via the National Clinical Database (NCD) for departments participating in the NCD, quality indicators (QIs) related to the treatment for PC, namely the board certification systems of various societies and the adherence to clinical practice guidelines for PC, were investigated between October 2014 and January 2015. A multivariable logistic regression analysis was performed to evaluate the relationship between the QIs and mortality of pancreaticoduodenectomy. RESULTS: Of 1415 departments that registered at least 1 pancreaticoduodenectomy between 2013 and 2014 in NCD, 631 departments (44.6%), which performed pancreaticoduodenectomy for a total of 11,684 cases, answered the questionnaire. The mortality of pancreaticoduodenectomy was positively affected by the board certification systems of the Japanese Society of Gastroenterological Surgery, Japanese Society of Hepato-Biliary-Pancreatic Surgery, Japanese Society of Gastroenterology, and Japanese Society of Medical Oncology as well as by institutions that used magnetic resonance imaging of ≥ 3 T for the diagnosis of PC in principle. CONCLUSIONS: The measurement of the appropriate QIs is suggested to help improve the mortality in pancreaticoduodenectomy. Masamichi Mizuma and Hiroyuki Yamamoto equally contributed.

Development of a model predicting the risk of eight major postoperative complications after esophagectomy based on 10 826 cases in the Japan National Clinical Database.

BACKGROUND: Esophagectomy is a highly invasive procedure with a high incidence of complications. The objectives of this study were to create risk prediction models for postoperative morbidity associated with esophagectomy and to test their performance using a population-based large database. METHODS: A total of 10 862 patients who underwent esophagectomy between January 2011 and December 2012 derived from the Japanese national clinical database (NCD) were included. Based on the 148 preoperative clinical variables collected, risk prediction models for eight major postoperative morbidities were created using 80% (8715 patients) of the study population and validated using the remaining 20% (2147 patients) of the patients. RESULTS: The mortality rate was 3.1% and postoperative morbidity was observed in 42.6% of the patients. The c-statistics of the eight risk models established by the training set were surgical site infection (0.564), anastomotic leakage (0.531), need for transfusion (0.636), blood loss >1000 mL (0.644), pneumonia (0.632), unplanned intubation (0.607), prolonged mechanical ventilation over 48 hours (0.614), and sepsis (0.618) in the validation analysis. CONCLUSIONS: Risk prediction models for postoperative morbidity after esophagectomy using the population-based large database showed relatively fair performance. The current models may offer baseline information for risk stratification in clinical decision makings and help select more suitable surgical and nonsurgical treatment options and future clinical studies.