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Development and validation of PRE-DELIRIC (PREdiction of DELIRium in ICu patients) delirium prediction model for intensive care patients: observational multicentre study

BMJ 2012; 344 doi: https://doi.org/10.1136/bmj.e420 (Published 09 February 2012) Cite this as: BMJ 2012;344:e420
  1. M van den Boogaard, intensive care nurse, scientific researcher, PhD student1,
  2. P Pickkers, professor in critical care1,
  3. A J C Slooter, intensivist2,
  4. M A Kuiper, intensivist3,
  5. P E Spronk, intensivist4,
  6. P H J van der Voort, intensivist5,
  7. J G van der Hoeven, professor in critical care1,
  8. R Donders, statistician6,
  9. T van Achterberg, professor in nursing7,
  10. L Schoonhoven, senior research fellow nursing science7
  1. 1Department of Intensive Care Medicine, Radboud University Nijmegen Medical Centre, 6500HB Nijmegen, Netherlands
  2. 2Department of Intensive Care, University Medical Centre Utrecht, Utrecht, Netherlands
  3. 3Department of Intensive Care, Medical Centre Leeuwarden, Leeuwarden, Netherlands
  4. 4Department of Intensive Care Medicine, Gelre Hospitals, Location Lukas, Apeldoorn, Netherlands
  5. 5Department of Intensive Care, Onze Lieve Vrouwe Gasthuis, Amsterdam, Netherlands
  6. 6Department of Epidemiology, Biostatistics and HTA, Radboud University Nijmegen Medical Centre
  7. 7Scientific Institute for Quality of Healthcare, Radboud University Nijmegen Medical Centre
  1. Correspondence to: M van den Boogaard M.vandenboogaard{at}ic.umcn.nl
  • Accepted 14 November 2011

Abstract

Objectives To develop and validate a delirium prediction model for adult intensive care patients and determine its additional value compared with prediction by caregivers.

Design Observational multicentre study.

Setting Five intensive care units in the Netherlands (two university hospitals and three university affiliated teaching hospitals).

Participants 3056 intensive care patients aged 18 years or over.

Main outcome measure Development of delirium (defined as at least one positive delirium screening) during patients’ stay in intensive care.

Results The model was developed using 1613 consecutive intensive care patients in one hospital and temporally validated using 549 patients from the same hospital. For external validation, data were collected from 894 patients in four other hospitals. The prediction (PRE-DELIRIC) model contains 10 risk factors—age, APACHE-II score, admission group, coma, infection, metabolic acidosis, use of sedatives and morphine, urea concentration, and urgent admission. The model had an area under the receiver operating characteristics curve of 0.87 (95% confidence interval 0.85 to 0.89) and 0.86 after bootstrapping. Temporal validation and external validation resulted in areas under the curve of 0.89 (0.86 to 0.92) and 0.84 (0.82 to 0.87). The pooled area under the receiver operating characteristics curve (n=3056) was 0.85 (0.84 to 0.87). The area under the curve for nurses’ and physicians’ predictions (n=124) was significantly lower at 0.59 (0.49 to 0.70) for both.

Conclusion The PRE-DELIRIC model for intensive care patients consists of 10 risk factors that are readily available within 24 hours after intensive care admission and has a high predictive value. Clinical prediction by nurses and physicians performed significantly worse. The model allows for early prediction of delirium and initiation of preventive measures.

Trial registration Clinical trials NCT00604773 (development study) and NCT00961389 (validation study).

Footnotes

  • We thank Gabriel Roodbol, delirium expert psychiatric nurse, who did all the inter-rater reliability measurements during the study. Thanks also to Henk Westerbaan, Maaike Fenten, and Wendy Groetelaers-Kusters, for collecting data during the absence of the first author and processing the data in SPSS. We also thank Sjef van der Velde for his support in gathering the national intensive care evaluation database information. Finally, we thank Gareth Parsons (University of Glamorgan, Faculty of Health, Sport and Science, UK) for his support with English grammar and spelling.

  • Contributors: MvdB conducted the study, collected all data, did the statistical analysis in collaboration with RD, and drafted the manuscript. PP and LS supervised the conduct of the study and writing of the paper. AJCS, MAK, PES, and PHJvdV gathered the data from the other hospitals and corrected the manuscript. JGvdH and TvA co-supervised and corrected the manuscript. MvdB and PP are the guarantors.

  • Funding: None.

  • Competing interests: All authors have completed the Unified Competing Interest form at http://www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.

  • Ethical approval: The regional medical ethical committee approved the study and waived the need for informed consent, as no additional interventions were carried out and data collection was not burdensome to patients.

  • Data sharing: No additional data available.

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