title: Risk model of valve surgery in Japan using the Japan Adult Cardiovascular Surgery Database.
abstract: OBJECTIVE
  Risk models of cardiac valve surgery using a large database are useful for improving surgical quality. In order to obtain accurate, high-quality assessments of surgical outcome, each geographic area should maintain its own database. The study aim was to collect Japanese data and to prepare a risk stratification of cardiac valve procedures, using the Japan Adult Cardiovascular Surgery Database (JACVSD).
  
  
  METHODS
  A total of 6562 valve procedure records from 97 participating sites throughout Japan was analyzed, using a data entry form with 255 variables that was sent to the JACVSD office from a web-based data collection system. The statistical model was constructed using multiple logistic regression. Model discrimination was tested using the area under the receiver operating characteristic curve (C-index). The model calibration was tested using the Hosmer-Lemeshow (H-L) test.
  
  
  RESULTS
  Among 6562 operated cases, 15% had diabetes mellitus, 5% were urgent, and 12% involved preoperative renal failure. The observed 30-day and operative mortality rates were 2.9% and 4.0%, respectively. Significant variables with high odds ratios included emergent or salvage status (3.83), reoperation (3.43), and left ventricular dysfunction (3.01). The H-L test and C-index values for 30-day mortality were satisfactory (0.44 and 0.80, respectively).
  
  
  CONCLUSIONS
  The results obtained in Japan were at least as good as those reported elsewhere. The performance of this risk model also matched that of the STS National Adult Cardiac Database and the European Society Database.
authors.affiliation: Department of Cardiac Surgery, Faculty of Medicine, Graduate School of Medicine, University of Tokyo, Japan. noboru@motomura.org
authors.forename: Noboru
authors.initials: N
authors.lastname: Motomura
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Miyata
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsukihara
authors.forename: Shinichi
authors.initials: S
authors.lastname: Takamoto
mesh_terms: D000368:Aged; D044466:Asian People / Q000706:statistics & numerical data*; D015897:Comorbidity; D019992:Databases as Topic; D005260:Female; D006305:Health Status Indicators; D006349:Heart Valve Diseases / Q000208:ethnology / Q000401:mortality / Q000601:surgery*; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000401:mortality; D006761:Hospitals / Q000706:statistics & numerical data; D006801:Humans; D020407:Internet; D007564:Japan; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D016017:Odds Ratio; D010043:Outcome and Process Assessment, Health Care / Q000706:statistics & numerical data*; D019984:Quality Indicators, Health Care / Q000706:statistics & numerical data*; D012372:ROC Curve; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D016896:Treatment Outcome