An evaluation of intensive care severity of illness scoring models

Livingston, Brian Mark (1999) An evaluation of intensive care severity of illness scoring models. PhD thesis, University of Glasgow.

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Objectives: To evaluate the accuracy of the four main Intensive Care severity of illness scoring models using a large Scottish database, and to investigate different strategies for improving their accuracy in a Scottish setting.Method: Twenty two out of 25 general adult Intensive Care Units in Scotland collected data for two and half years to allow calculation of Acute Physiology and Chronic Health Evaluation (APACHE) version II and III, Simplified Acute Physiology Score (SAPS) version II, Mortality Probability Model (MPM) version II (calculated on admission and at 24 hours). The models' Goodness of Fit (discrimination and calibration) and performances in subgroups (Uniformity of Fit) were evaluated using Receiver Operating Characteristic Curves, Hosmer-Lemeshow Goodness of Fit test, Chi Squared test and Confidence Intervals. Three of the Models (APACHE II, SAPS II, and MPM II) were customised with Scottish data using logistic regression techniques.Results: All models had good discrimination but poor calibration. However, the SAPS II and APACHE II models appeared to have better calibration than other models.All models, except the new APACHE II model, showed significant differences in important subgroups.Conclusions: Questions remain about the accuracy of these models even after customisation. Further research is needed to investigate variations in Intensive Care Units and the relationship to clinical effectiveness. However, where case mix adjustment is needed the new customised models remain the most accurate means of doing this in Scottish data

Item Type: Thesis (PhD)
Qualification Level: Doctoral
Subjects: R Medicine > R Medicine (General)
Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
Supervisor's Name: Supervisor, not known
Date of Award: 1999
Depositing User: Mrs Marie Cairney
Unique ID: glathesis:1999-6906
Copyright: Copyright of this thesis is held by the author.
Date Deposited: 26 Nov 2015 16:05
Last Modified: 02 Dec 2015 13:31

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