title: Prediction model for critically ill patients with acute respiratory distress syndrome.
abstract: OBJECTIVE
  Acute respiratory distress syndrome (ARDS) is a major cause respiratory failure in intensive care unit (ICU). Early recognition of patients at high risk of death is of vital importance in managing them. The aim of the study was to establish a prediction model by using variables that were readily available in routine clinical practice.
  
  
  METHODS
  The study was a secondary analysis of data obtained from the NHLBI Biologic Specimen and Data Repository Information Coordinating Center. Patients were enrolled between August 2007 and July 2008 from 33 hospitals. Demographics and laboratory findings were extracted from dataset. Univariate analyses were performed to screen variables with p<0.3. Then these variables were subject to automatic stepwise forward selection with significance level of 0.1. Interaction terms and fractional polynomials were examined for variables in the main effect model. Multiple imputations and bootstraps procedures were used to obtain estimations of coefficients with better external validation. Overall model fit and logistic regression diagnostics were explored.
  
  
  RESULTS
  A total of 282 ARDS patients were included for model development. The final model included eight variables without interaction terms and non-linear functions. Because the variable coefficients changed substantially after exclusion of most poorly fitted and influential subjects, we estimated the coefficient after exclusion of these outliers. The equation for the fitted model was: g(Χ)=0.06×age(in years)+2.23(if on vasopressor)+1.37×potassium (mmol/l)-0.007×platelet count (×109)+0.03×heart rate (/min)-0.29×Hb(g/dl)-0.67×T(°C)+0.01×PaO_2+13, and the probability of death π(Χ)=eg(Χ)/(1+eg(Χ)).
  
  
  CONCLUSIONS
  The study established a prediction model for ARDS patients requiring mechanical ventilation. The model was examined with rigorous methodology and can be used for risk stratification in ARDS patients.
authors.affiliation: Department of Critical Care Medicine, Jinhua Municipal Central Hospital, Jinhua Hospital of Zhejiang University, Zhejiang, P.R. China.
authors.forename: Zhongheng
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Critical Care Medicine, Jinhua Municipal Central Hospital, Jinhua Hospital of Zhejiang University, Zhejiang, P.R. China.
authors.forename: Hongying
authors.initials: H
authors.lastname: Ni
mesh_terms: D016638:Critical Illness; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D012128:Respiratory Distress Syndrome / Q000175:diagnosis*; D012307:Risk Factors
references.citation: Thorax. 1998 Apr;53(4):292-4
references.pmid: 9741374
references.citation: Crit Care. 2007;11(3):R53
references.pmid: 17493273
references.citation: Crit Care Med. 2014 Jul;42(7):1610-8
references.pmid: 24732240
references.citation: Intensive Care Med. 2014 Aug;40(8):1184
references.pmid: 24993464
references.citation: Am J Respir Crit Care Med. 1994 Mar;149(3 Pt 1):818-24
references.pmid: 7509706
references.citation: Intensive Care Med. 1996 Jun;22(6):519-29
references.pmid: 8814466
references.citation: Methods Inf Med. 2005;44(4):561-71
references.pmid: 16342923
references.citation: N Engl J Med. 2005 Oct 20;353(16):1685-93
references.pmid: 16236739
references.citation: J Trauma Acute Care Surg. 2013 Jan;74(1):196-202
references.pmid: 23147176
references.citation: Resuscitation. 2013 Mar;84(3):280-5
references.pmid: 22863543
references.citation: JAMA. 2012 Jun 20;307(23):2526-33
references.pmid: 22797452
references.citation: Am J Respir Crit Care Med. 1995 Feb;151(2 Pt 1):293-301
references.pmid: 7842182
references.citation: Psychosom Med. 2004 May-Jun;66(3):411-21
references.pmid: 15184705
references.citation: Am J Public Health. 1991 Dec;81(12):1630-5
references.pmid: 1746660
references.citation: Am J Respir Crit Care Med. 2011 Jan 1;183(1):59-66
references.pmid: 20693377
references.citation: J Nephrol. 2014 Feb;27(1):65-71
references.pmid: 24424722
references.citation: Am J Epidemiol. 1982 Jan;115(1):92-106
references.pmid: 7055134
references.citation: Respir Care. 2011 Apr;56(4):420-8
references.pmid: 21255500
references.citation: Int J Epidemiol. 2007 Feb;36(1):195-202
references.pmid: 17329317
references.citation: Eur J Cardiothorac Surg. 2008 Oct;34(4):898-902
references.pmid: 18768325
references.citation: Comput Biol Med. 2014 Apr;47:13-9
references.pmid: 24508564
references.citation: Stat Methods Med Res. 1999 Mar;8(1):3-15
references.pmid: 10347857
references.citation: Ann Intern Med. 1995 Jan 1;122(1):17-23
references.pmid: 7985891
references.citation: Stat Med. 2007 Dec 30;26(30):5512-28
references.pmid: 18058845
references.citation: Ann Stat. 2012;40(2):785-811
references.pmid: 23152646
references.citation: Chest. 2013 Apr;143(4):910-9
references.pmid: 23632902
references.citation: Front Pediatr. 2014 Jul 25;2:78
references.pmid: 25121078
references.citation: Am J Respir Crit Care Med. 2011 Sep 1;184(5):561-8
references.pmid: 21562125
references.citation: Intensive Care Med. 2014 Jun;40(6):769-87
references.pmid: 24667919
references.citation: J Crit Care. 2013 Oct;28(5):816-24
references.pmid: 23849541
references.citation: Chest. 1999 Jul;116(1 Suppl):74S-82S
references.pmid: 10424602
references.citation: Crit Care Med. 2015 Feb;43(2):346-53
references.pmid: 25393701
references.citation: Intensive Care Med. 2014 Jun;40(6):900-2
references.pmid: 24718644
references.citation: Stat Med. 2000 May 15;19(9):1141-64
references.pmid: 10797513
references.citation: J Crit Care. 2014 Oct;29(5):885.e1-6
references.pmid: 24895093