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Kotting J.,BQS Institute for Quality and Patient Safety | Schiller W.,University of Bonn | Beckmann A.,Heart Center Duisburg | Schafer E.,BQS Institute for Quality and Patient Safety | And 4 more authors.
European Journal of Cardio-thoracic Surgery | Year: 2013

Objectives: The aim of the study was to establish a scoring system to predict mortality in aortic valve procedures in adults [German Aortic Valve Score (German AV Score)] based upon the comprehensive data pool mandatory by law in Germany. Methods: In 2008, 11 794 cases were documented who had either open aortic valve surgery or transcatheter aortic valve implantation (TAVI). In-hospital mortality was chosen as a binary outcome measure. Potential risk factors were identified on the basis of published scoring systems and clinical knowledge. First, each of these risk factors was tested in an univariate manner by Fisher's exact test for significant influence on mortality. Then, a multiple logistic regression model with backward and forward selection was used. Calibration was ascertained by the Hosmer-Lemeshow method. In order to define the quality of discrimination, the area under the receiver operating characteristic (ROC) curve was calculated. Results: In 11 147 of 11 794 cases (94.5%), a complete data set was available. In-hospital mortality was 3.7% for all patients, 3.4% in the surgical group (95% confidence interval 3.0-3.7%, n = 10 574) and 10.6% in the TAVI group (95% confidence interval 8.2-13.5%, n = 573). Based on multiple logistic regression, 15 risk factors with an influence on mortality were identified. Among them, age, body mass index and left ventricular function were categorized in three (body mass index, left ventricular dysfunction) or 6 subgroups (age). The Hosmer-Lemeshow method corroborated a valid concordance of predicted and observed mortality in 10 different risk groups. The area under the ROC curve with a value of 0.808 affirmed the quality of discrimination of the established scoring model. Conclusions: It is well known that a predictive model works best in the setting where it was developed; therefore, the German AV Score fits well to the patient population in Germany. It was designed for fair and reliable outcome evaluation. It allows comparison of predicted and observed mortality for conventional aortic valve surgery and transcatheter aortic valve implantation in low-, moderateand high-risk groups. Thus, it enables primarily a risk-adjusted benchmark of outcome and fosters the efforts for continuous improvement of quality in aortic valve procedures. © The Author 2013. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.


Kotting J.,BQS Institute for Quality and Patient Safety | Beckmann A.,Heart Center Duisburg | Dobler K.,Competence Center for Quality Management | Schafer E.,BQS Institute for Quality and Patient Safety | And 3 more authors.
Thoracic and Cardiovascular Surgeon | Year: 2014

Background A specific risk model concerning mortality of patients undergoing isolated coronary artery bypass grafting (CABG) is developed based on the national quality benchmarking mandatory by law in Germany. Methods On the basis of the national data pool from 2004, a risk score model for patients undergoing isolated CABG was developed and finally adjusted with the data of 43,145 patients of the year 2008. Modeling was performed by logistic regression analysis. This risk model was validated with the 2007 data pool which comprised 45,569 patients. Results Observed in-hospital mortality after isolated CABG procedures was 3.0% in 2008. Hosmer-Lemeshow test p value was 0.189 and area under receiver operating characteristic curve was 0.826. Applying the German CABG score for 2007 resulted in an observed-to-expected mortality ratio of 1.01. Conclusion The German CABG score for in-hospital mortality is a risk score with proven validity for isolated CABG, developed by means of the patient population in Germany. It can be used for the assessment of patient risk groups and for interhospital benchmarking. We encourage other researchers to apply and validate this score in comparable health care systems. © 2014 Georg Thieme Verlag KG Stuttgart · New York.


PubMed | BQS Institute for Quality and Patient Safety, University of Bonn, Competence Center for Quality Management and Heart Center Duisburg
Type: Journal Article | Journal: The Thoracic and cardiovascular surgeon | Year: 2014

A specific risk model concerning mortality of patients undergoing isolated coronary artery bypass grafting (CABG) is developed based on the national quality benchmarking mandatory by law in Germany.On the basis of the national data pool from 2004, a risk score model for patients undergoing isolated CABG was developed and finally adjusted with the data of 43,145 patients of the year 2008. Modeling was performed by logistic regression analysis. This risk model was validated with the 2007 data pool which comprised 45,569 patients.Observed in-hospital mortality after isolated CABG procedures was 3.0% in 2008. Hosmer-Lemeshow test p value was 0.189 and area under receiver operating characteristic curve was 0.826. Applying the German CABG score for 2007 resulted in an observed-to-expected mortality ratio of 1.01.The German CABG score for in-hospital mortality is a risk score with proven validity for isolated CABG, developed by means of the patient population in Germany. It can be used for the assessment of patient risk groups and for interhospital benchmarking. We encourage other researchers to apply and validate this score in comparable health care systems.

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