Index Blood Tests and National Early Warning Scores within 24 Hours of Emergency Admission Can Predict the Risk of In-Hospital Mortality: A Model Development and Validation Study
Open Access
- 29 May 2013
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 8 (5), e64340
- https://doi.org/10.1371/journal.pone.0064340
Abstract
We explored the use of routine blood tests and national early warning scores (NEWS) reported within ±24 hours of admission to predict in-hospital mortality in emergency admissions, using empirical decision Tree models because they are intuitive and may ultimately be used to support clinical decision making. A retrospective analysis of adult emergency admissions to a large acute hospital during April 2009 to March 2010 in the West Midlands, England, with a full set of index blood tests results (albumin, creatinine, haemoglobin, potassium, sodium, urea, white cell count and an index NEWS undertaken within ±24 hours of admission). We developed a Tree model by randomly splitting the admissions into a training (50%) and validation dataset (50%) and assessed its accuracy using the concordance (c-) statistic. Emergency admissions (about 30%) did not have a full set of index blood tests and/or NEWS and so were not included in our analysis. There were 23248 emergency admissions with a full set of blood tests and NEWS with an in-hospital mortality of 5.69%. The Tree model identified age, NEWS, albumin, sodium, white cell count and urea as significant (pc-statistic for the training model was 0.864 (95%CI 0.852 to 0.87) and when applied to the testing data set this was 0.853 (95%CI 0.840 to 0.866). An easy to interpret validated risk adjustment Tree model using blood test and NEWS taken within ±24 hours of admission provides good discrimination and offers a novel approach to risk adjustment which may potentially support clinical decision making. Given the nature of the clinical data, the results are likely to be generalisable but further research is required to investigate this promising approach.Keywords
This publication has 43 references indexed in Scilit:
- Preventable deaths due to problems in care in English acute hospitals: a retrospective case record review studyBMJ Quality & Safety, 2012
- Variations in hospital standardised mortality ratios (HSMR) as a result of frequent readmissionsBMC Health Services Research, 2012
- pROC: an open-source package for R and S+ to analyze and compare ROC curvesBMC Bioinformatics, 2011
- Adverse events and potentially preventable deaths in Dutch hospitals: results of a retrospective patient record review studyQuality and Safety in Health Care, 2009
- Performance of in-hospital mortality prediction models for acute hospitalization: Hospital Standardized Mortality Ratio in JapanBMC Health Services Research, 2008
- Measuring and explaining mortality in Dutch hospitals; The Hospital Standardized Mortality Rate between 2003 and 2005BMC Health Services Research, 2008
- Case-mix adjustment in non-randomised observational evaluations: the constant risk fallacyJournal of Epidemiology and Community Health, 2007
- The value of administrative databasesBMJ, 2007
- Use of administrative data or clinical databases as predictors of risk of death in hospital: comparison of modelsBMJ, 2007
- Unbiased Recursive Partitioning: A Conditional Inference FrameworkJournal of Computational and Graphical Statistics, 2006