title: Clinical Results and Outcome Improvement Over Time in Traumatic Brain Injury.
abstract: Prognostic models for traumatic brain injury (TBI) are important tools both in clinical practice and research if properly validated, preferably by external validation. Prognostic models also offer the possibility of monitoring performance by comparing predicted outcomes with observed outcomes. In this study, we applied the prognostic models developed by the International Mission on Prognosis and Analysis of Clinical Trials in TBI (IMPACT) in an Italian multi-center database (Neurolink) with two aims: to compare observed with predicted outcomes and to check for a possible improvement of clinical outcome over the 11 years of patient inclusion in Neurolink. We applied the IMPACT models to patients included in Neurolink between 1997 and 2007. Performance of the models was assessed by determining calibration (with calibration plots) and discrimination (by the area under the receiver operating characteristic curve [AUC]). Logistic regression analysis was used to analyze a possible trend in outcomes over time, adjusted for predicted outcomes. A total of 1401 patients were studied. Patients had a median age of 40 years and 51% had a Glasgow Coma Scale motor score of 5 or 6. The models showed good discrimination, with AUCs of 0.86 (according to the Core Model) and 0.88 (Extended Model), and adequate calibration, with the overall observed risk of unfavorable outcome and mortality being less than predicted. Outcomes significantly improved over time. This study shows that the IMPACT models performed reasonably well in the Neurolink data and can be used for monitoring performance. After adjustment for predicted outcomes with the prognostic models, we observed a substantial improvement of patient outcomes over time in the three Neurolink centers.
authors.affiliation: 6 Department of Anesthesiology and Intensive Care, Neurointensive Care Unit, Fondazione IRCCS Cà Granda , Ospedale Maggiore Policlinico, Milan, Italy .
authors.forename: Priscilla
authors.initials: P
authors.lastname: Di Deo
authors.affiliation: 2 Department of Public Health, Erasmus University Medical Center , Rotterdam, the Netherlands .
authors.forename: Hester
authors.initials: H
authors.lastname: Lingsma
authors.affiliation: 2 Department of Public Health, Erasmus University Medical Center , Rotterdam, the Netherlands .
authors.forename: Daan
authors.initials: D
authors.lastname: Nieboer
authors.affiliation: 3 Department of Neurology, Erasmus University Medical Center , Rotterdam, the Netherlands .
authors.forename: Bob
authors.initials: B
authors.lastname: Roozenbeek
authors.affiliation: 4 School of Medicine and Surgery, University of Milan-Bicocca; Neurointensive Care , San Gerardo Hospital, Monza, Italy .
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Citerio
authors.affiliation: 5 Neurointensive Care Unit, Scientific Institute , San Raffaele Hospital, Milan, Italy .
authors.forename: Luigi
authors.initials: L
authors.lastname: Beretta
authors.affiliation: 1 Department of Physiopathology and Transplantation, Milan University , Milan, Italy .|6 Department of Anesthesiology and Intensive Care, Neurointensive Care Unit, Fondazione IRCCS Cà Granda , Ospedale Maggiore Policlinico, Milan, Italy .
authors.forename: Sandra
authors.initials: S
authors.lastname: Magnoni
authors.affiliation: 7 Department of Neuroscience, IRCCS Istituto Mario Negri , Milan, Italy .
authors.forename: Elisa R
authors.initials: ER
authors.lastname: Zanier
authors.affiliation: 1 Department of Physiopathology and Transplantation, Milan University , Milan, Italy .|6 Department of Anesthesiology and Intensive Care, Neurointensive Care Unit, Fondazione IRCCS Cà Granda , Ospedale Maggiore Policlinico, Milan, Italy .
authors.forename: Nino
authors.initials: N
authors.lastname: Stocchetti
mesh_terms: D000328:Adult; D000368:Aged; D000070642:Brain Injuries, Traumatic / Q000000981:diagnostic imaging* / Q000401:mortality*; D016208:Databases, Factual / Q000639:trends; D005260:Female; D006801:Humans; D007362:Intensive Care Units / Q000639:trends*; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D015599:Trauma Severity Indices; D055815:Young Adult
keywords: outcome; prognostic models; traumatic brain injury