title: External validation of two prediction models identifying employees at risk of high sickness absence: cohort study with 1-year follow-up.
abstract: BACKGROUND
  Two models including age, self-rated health (SRH) and prior sickness absence (SA) were found to predict high SA in health care workers. The present study externally validated these prediction models in a population of office workers and investigated the effect of adding gender as a predictor.
  
  
  METHODS
  SRH was assessed at baseline in a convenience sample of office workers. Age, gender and prior SA were retrieved from an occupational health service register. Two pre-defined prediction models were externally validated: a model identifying employees with high (i.e. ≥30) SA days and a model identifying employees with high (i.e. ≥3) SA episodes during 1-year follow-up. Calibration was investigated by plotting the predicted and observed probabilities and calculating the calibration slope. Discrimination was examined by receiver operating characteristic (ROC) analysis and the area under the ROC-curve (AUC).
  
  
  RESULTS
  A total of 593 office workers had complete data and were eligible for analysis. Although the SA days model showed acceptable calibration (slope = 0.89), it poorly discriminated office workers with high SA days from those without high SA days (AUC = 0.65; 95% CI 0.58-0.71). The SA episodes model showed acceptable discrimination (AUC = 0.76, 95% CI 0.70-0.82) and calibration (slope = 0.96). The prognostic performance of the prediction models did not improve in the population of office workers after adding gender.
  
  
  CONCLUSIONS
  The SA episodes model accurately predicted the risk of high SA episodes in office workers, but needs further multisite validation and requires a simpler presentation format before it can be used to select high-risk employees for interventions to prevent or reduce SA.
authors: 365/Occupational Health Service, PO Box 85091, 3508 AB, Utrecht, the Netherlands. corne.roelen@365.nl
authors: Corné A M
authors: CA
authors: Roelen
authors: Ute
authors: U
authors: Bültmann
authors: Willem
authors: W
authors: van Rhenen
authors: Jac J L
authors: JJ
authors: van der Klink
authors: Jos W R
authors: JW
authors: Twisk
authors: Martijn W
authors: MW
authors: Heymans
mesh_terms: D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D018582:Sick Leave / Q000706:statistics & numerical data*
references: Occup Med (Lond). 2008 Sep;58(6):413-8
references: 18567614
references: Work. 2008;30(4):377-87
references: 18725701
references: Occup Environ Med. 2008 Jan;65(1):28-31
references: 17626139
references: JAMA. 2000 Jul 5;284(1):79-84
references: 10872017
references: J Occup Environ Med. 2008 Jul;50(7):765-76
references: 18617832
references: Occup Med (Lond). 2006 Oct;56(7):442-6
references: 16905625
references: J Epidemiol Community Health. 2005 May;59(5):342-5
references: 15831678
references: BMC Public Health. 2007 May 02;7:67
references: 17474980
references: Stat Med. 2005 Sep 30;24(18):2867-72
references: 16134131
references: Psychosom Med. 2004 May-Jun;66(3):411-21
references: 15184705
references: Occup Environ Med. 2006 Mar;63(3):212-7
references: 16497865
references: J Epidemiol Community Health. 2011 Sep;65(9):800-6
references: 20551149
references: Eur J Public Health. 2013 Feb;23(1):128-33
references: 22539631
references: J Clin Epidemiol. 2003 Sep;56(9):826-32
references: 14505766
references: Epidemiology. 2010 Jan;21(1):128-38
references: 20010215
references: Ann Intern Med. 1999 Mar 16;130(6):515-24
references: 10075620
references: Occup Environ Med. 2006 Aug;63(8):564-9
references: 16698807
references: Occup Environ Med. 2008 Apr;65(4):236-41
references: 17681994
references: Health Place. 2006 Dec;12(4):728-33
references: 16814198
references: J Clin Epidemiol. 2003 Aug;56(8):721-9
references: 12954463
references: J Occup Rehabil. 2008 Mar;18(1):79-86
references: 18196446
references: Occup Environ Med. 2008 Jul;65(7):494-9
references: 18032531
references: Psychol Health Med. 2009 Aug;14(4):405-18
references: 19697251
references: Occup Environ Med. 2008 Apr;65(4):242-8
references: 17933885
references: BMC Public Health. 2008 Dec 30;8:426
references: 19116000
references: J Clin Epidemiol. 1999 Aug;52(8):731-5
references: 10465317
references: BMJ. 2003 Aug 16;327(7411):364
references: 12919985
references: J Epidemiol Community Health. 1995 Apr;49(2):124-30
references: 7798038
references: Occup Med (Lond). 2008 Jun;58(4):268-74
references: 18390880
references: J Clin Epidemiol. 2009 Apr;62(4):408-414.e2
references: 18986798
references: J Clin Epidemiol. 1997 Oct;50(10):1123-8
references: 9368520
references: Scand J Public Health Suppl. 2004;63:49-108
references: 15513654
references: CJEM. 2006 Jan;8(1):19-20
references: 17175625
references: Stat Med. 2004 Aug 30;23(16):2567-86
references: 15287085