The Royal Free Hospital score: a calibrated prognostic model for patients with cirrhosis admitted to intensive care unit. Comparison with current models and CLIF-SOFA score.
OBJECTIVE
Prognosis for patients with cirrhosis admitted to intensive care unit (ICU) is poor. ICU prognostic models are more accurate than liver-specific models. We identified predictors of mortality, developed a novel prognostic score (Royal Free Hospital (RFH) score), and tested it against established prognostic models and the yet unvalidated Chronic Liver Failure-Sequential Organ Failure Assessment (CLIF-SOFA) model.


METHODS
Predictors of mortality were defined by logistic regression in a cohort of 635 consecutive patients with cirrhosis admitted to ICU (1989-2012). The RFH score was derived using a 75% training and 25% validation set. Predictive accuracy and calibration were evaluated using area under the receiver operating characteristic (AUROC) and goodness-of-fit χ(2) for the RFH score, as well as for SOFA, Model for End-Stage Liver Disease (MELD), Acute Physiology and Chronic Health Evaluation (APACHE II), and Child-Pugh. CLIF-SOFA was applied to a recent subset (2005-2012) of patients.


RESULTS
In-hospital mortality was 52.3%. Mortality improved over time but with a corresponding reduction in acuity of illness on admission. Predictors of mortality in training set, which constituted the RFH score, were the following: bilirubin, international normalized ratio, lactate, alveolar arterial partial pressure oxygen gradient, urea, while variceal bleeding as indication for admission conferred lesser risk. Classification accuracy was 73.4% in training and 76.7% in validation sample and did not change significantly across different eras of admission. The AUROC for the derived model was 0.83 and the goodness-of-fit χ(2) was 3.74 (P=0.88). AUROC for SOFA was 0.81, MELD was 0.79, APACHE II was 0.78, and Child-Pugh was 0.67. In 2005-2012 cohort, AUROC was: SOFA: 0.74, CLIF-SOFA: 0.75, and RFH: 0.78. Goodness-of-fit χ(2) was: SOFA: 6.21 (P=0.63), CLIF-SOFA: 9.18 (P=0.33), and RFH: 2.91 (P=0.94).


CONCLUSIONS
RFH score demonstrated good discriminative ability and calibration. Internal validation supports its generalizability. CLIF-SOFA did not perform better than RFH and the original SOFA. External validation of our model should be undertaken to confirm its clinical utility.
The Royal Free Sheila Sherlock Liver Centre, Royal Free Hospital, Royal Free Hampstead NHS Trust and Institute of Liver and Digestive Health, University College London, London, UK.
Eleni
E
Theocharidou
The Royal Free Sheila Sherlock Liver Centre, Royal Free Hospital, Royal Free Hampstead NHS Trust and Institute of Liver and Digestive Health, University College London, London, UK.
Giulia
G
Pieri
Intensive Care Unit, Royal Free Hospital, Royal Free Hampstead NHS Trust, University College London, London, UK.
Ali Omar
AO
Mohammad
The Royal Free Sheila Sherlock Liver Centre, Royal Free Hospital, Royal Free Hampstead NHS Trust and Institute of Liver and Digestive Health, University College London, London, UK.
Michelle
M
Cheung
The Royal Free Sheila Sherlock Liver Centre, Royal Free Hospital, Royal Free Hampstead NHS Trust and Institute of Liver and Digestive Health, University College London, London, UK.
Evangelos
E
Cholongitas
Banwari
B
Agarwal
Intensive Care Unit, Royal Free Hospital, Royal Free Hampstead NHS Trust, University College London, London, UK.
Agarwal
A
Banwari
The Royal Free Sheila Sherlock Liver Centre, Royal Free Hospital, Royal Free Hampstead NHS Trust and Institute of Liver and Digestive Health, University College London, London, UK.
Andrew K
AK
Burroughs
D018806:APACHE; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002138:Calibration; D003422:Critical Care; D003661:Decision Support Techniques; D005260:Female; D006305:Health Status Indicators; D017052:Hospital Mortality; D006801:Humans; D008103:Liver Cirrhosis / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012372:ROC Curve; D015203:Reproducibility of Results; D055815:Young Adult