@article{88880effa5b540a69e328e610b093dda,
title = "Pre-operative Nomogram to Predict Risk of Peri-operative Mortality following Liver Resections for Malignancy",
abstract = "Introduction: The majority of liver resections for malignancy are performed in older patient with major co-morbidities. There is currently no pre-operative, patient-specific method to determine the likely peri-operative mortality for each individual patient. The aim of this study was to develop a pre-operative nomogram based on the presence of co-morbidities to predict risk of peri-operative mortality following liver resections for malignancy. Methods: The Nationwide Inpatient Sample database was queried to identify adult patients that underwent liver resection for malignancy. The pre-operative co-morbidities, identified as predictors were used and a nomogram was created with multivariate regression using Taylor expansion method in SAS software, SURVEYLOGISTIC procedure. Training set (years 2000-2004) was utilized to develop the model and validation set (year 2005) was utilized to validate this model. Results: A total of 3,947 and 972 patients were included in training and validation sets, respectively. The overall actual-observed peri-operative mortality rates for training and validation sets were 4.1% and 3.2%, respectively. The decile-based calibration plots for the training set revealed good agreement between the observed probabilities and nomogram-predicted probabilities. Similarly, the quartile-based calibration plot for the validation set revealed good agreement between the observed and predicted probabilities. The accuracy of the nomogram was further reinforced by a good concordance index of 0.80 with a 95% confidence interval of 0.72 and 0.87. Conclusions: This pre-operative nomogram may be utilized to predict the risk of peri-operative mortality following liver resection for malignancy.",
keywords = "Liver resections, Malignancy, Nomogram, Peri-operative mortality",
author = "Mashaal Dhir and Smith, {Lynette M.} and Fred Ullrich and Leiphrakpam, {Premila D.} and Ly, {Quan P.} and Sasson, {Aaron R.} and Chandrakanth Are",
note = "Funding Information: Data was obtained from the NIS (http://www.hcup-us.ahrq. gov/nisoverview.jsp) a database developed as part of the Healthcare Cost and Utilization Project (HCUP), sponsored by the Agency for Healthcare Research and Quality. The NIS is designed to approximate a 20% sample of US community hospitals. In 2005, the NIS database contained discharge data from 1,054 hospitals located in 37 states (HCUP, Nationwide Inpatient Sample, Rockville, MD: Agency for Health Care Research and Quality; 2005). Data for this study was compiled from the 2000 to 2005 versions of the NIS. All patients discharged with an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) primary procedure code for hepatic wedge resection (code 50.22) or hepatic lobe resection (code 50.3) were included in the study. Diagnoses codes 155.0 and 155.1 were used for primary liver malignancies whereas code 197.7 was used for secondary malignancies of the liver. Data on patient age and sex, admission type, hospital size and type, and resection type were extracted from the database. The patients that underwent lobectomy plus wedge resection were included in the lobectomy group although the sample size was noted to be small. Co-morbidities were identified using the taxonomy published by Elixhauser et al.20 Elixhauser{\textquoteright}s list is a very comprehensive list, specifically designed for administrative databases and includes co-morbidities which can potentially impact outcomes including length of stay, hospital cost, and in-hospital mortality. Table 1 summarizes a partial list of definition of some of the pre-operative co-morbidities used to construct the nomogram. A comprehensive list has been previously published by Elixhauser et al.20",
year = "2010",
doi = "10.1007/s11605-010-1352-2",
language = "English (US)",
volume = "14",
pages = "1770--1781",
journal = "Journal of Gastrointestinal Surgery",
issn = "1091-255X",
publisher = "Springer New York",
number = "11",
}