title: Prediction models for prolonged intensive care unit stay after cardiac surgery: systematic review and validation study.
abstract: BACKGROUND
  Several models have been developed to predict prolonged stay in the intensive care unit (ICU) after cardiac surgery. However, no extensive quantitative validation of these models has yet been conducted. This study sought to identify and validate existing prediction models for prolonged ICU length of stay after cardiac surgery.
  
  
  RESULTS
  After a systematic review of the literature, the identified models were applied on a large registry database comprising 11 395 cardiac surgical interventions. The probabilities of prolonged ICU length of stay based on the models were compared with the actual outcome to assess the discrimination and calibration performance of the models. Literature review identified 20 models, of which 14 could be included. Of the 6 models for the general cardiac surgery population, the Parsonnet model showed the best discrimination (area under the receiver operating characteristic curve=0.75 [95% confidence interval, 0.73 to 0.76]), followed by the European system for cardiac operative risk evaluation (EuroSCORE) (0.71 [0.70 to 0.72]) and a model by Huijskes and colleagues (0.71 [0.70 to 0.73]). Most of the models showed good calibration.
  
  
  CONCLUSIONS
  In this validation of prediction models for prolonged ICU length of stay, 2 widely implemented models (Parsonnet, EuroSCORE), although originally designed for prediction of mortality, were superior in identifying patients with prolonged ICU length of stay.
authors.affiliation: University of Applied Science Utrecht, Faculty of Health Care, Bolognalaan 101 3584 CJ Utrecht, Netherlands. Roelof.Ettema@hu.nl
authors.forename: Roelof G A
authors.initials: RG
authors.lastname: Ettema
authors.forename: Linda M
authors.initials: LM
authors.lastname: Peelen
authors.forename: Marieke J
authors.initials: MJ
authors.lastname: Schuurmans
authors.forename: Arno P
authors.initials: AP
authors.lastname: Nierich
authors.forename: Cor J
authors.initials: CJ
authors.lastname: Kalkman
authors.forename: Karel G M
authors.initials: KG
authors.lastname: Moons
mesh_terms: D000368:Aged; D006348:Cardiac Surgical Procedures / Q000592:standards / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007362:Intensive Care Units / Q000592:standards / Q000706:statistics & numerical data*; D007902:Length of Stay / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011184:Postoperative Period; D011237:Predictive Value of Tests; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome