title: Screening manual and office workers for risk of long-term sickness absence: cut-off points for the Work Ability Index.
abstract: OBJECTIVE
  The aim of this study was to investigate the Work Ability Index (WAI) as a tool to screen for risk of different durations of long-term sickness absence (LTSA) among manual and office workers.
  
  
  METHODS
  The prospective study comprised a cohort of 3049 (1710 manual and 1339 office) workers participating in occupational health surveys between 2010-2012. The survey date was set as baseline and incident LTSA episodes of different duration (>14, >28, >42, >60, and >90 days) were retrieved from an occupational health register in the year following the survey. Baseline WAI scores were associated with LTSA episodes occurring (no/yes) during one-year follow-up by logistic regression analysis in a random sample (N=1000) of the cohort. Predictions of LTSA risk were then validated among the workers not included in the random sample.
  
  
  RESULTS
  The odds of LTSA episodes at follow-up decreased with increasing baseline WAI scores (ie, better work ability). The WAI accurately predicted the risk of future LTSA episodes >28, >42, >60 days, but over-predicted the risk of LTSA episodes >14 and >90 days. The WAI discriminated between workers at high and low risk of LTSA episodes of all durations. Office workers had higher WAI scores than manual workers. Consequently, false-negative rates were higher among office workers and false-positive rates were higher among manual workers at each WAI cut-off point.
  
  
  CONCLUSIONS
  The WAI could be used to screen both manual and office workers for risk of LTSA episodes lasting >28, >42, >60 days. WAI cut-off points depend on the objectives of screening and may differ for manual and office workers.
authors.affiliation: Dr Roelen, ArboNed, PO Box 85091, 3508 AB Utrecht, The Netherlands. corne.roelen@arboned.nl.
authors.forename: Lianne S
authors.initials: LS
authors.lastname: Schouten
authors.forename: Catelijne I
authors.initials: CI
authors.lastname: Joling
authors.forename: Joost W J
authors.initials: JW
authors.lastname: van der Gulden
authors.forename: Martijn W
authors.initials: MW
authors.lastname: Heymans
authors.forename: Ute
authors.initials: U
authors.lastname: Bültmann
authors.forename: Corné A  M
authors.initials: CA
authors.lastname: Roelen
mesh_terms: D000041:Absenteeism; D000328:Adult; D005189:False Positive Reactions; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D009790:Occupations / Q000706:statistics & numerical data*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018582:Sick Leave / Q000706:statistics & numerical data*; D014938:Work Capacity Evaluation; D017132:Workplace / Q000706:statistics & numerical data*