title: Influence of new secondary diagnoses on the duration of non-work-related sickness absence episodes.
abstract: OBJECTIVE
  To describe the frequency and distribution of new diagnoses (codiagnoses) arising during a sickness absence (SA) episode, and to analyze their effect on duration of non-work-related SA in Spain.
  
  
  METHODS
  Prospective cohort study from 2004 to 2007. Overall, 15,246 episodes occurred in a population base of 632,000 workers. Median duration of the episodes was the measured outcome. A Cox survival analysis, stratified by sex, estimated the hazard ratio to case closure adjusting by initial diagnosis, codiagnoses, demographic, and employment-related variables.
  
  
  RESULTS
  The effect of an increasing number of codiagnoses on duration of the SA episode was evidenced by a progressively decreasing hazard ratio. This was present in both sexes, although the effect was greater in men.
  
  
  CONCLUSIONS
  New conditions arising in the course of a SA episode significantly prolong its duration.
authors.affiliation: Center for Research in Occupational Health, Universitat Pompeu Fabra, Barcelona, Spain.
authors.forename: Mònica
authors.initials: M
authors.lastname: Ubalde-López
authors.forename: George L
authors.initials: GL
authors.lastname: Delclos
authors.forename: Eva
authors.initials: E
authors.lastname: Calvo
authors.forename: Fernando G
authors.initials: FG
authors.lastname: Benavides
mesh_terms: D000328:Adult; D015897:Comorbidity / Q000639:trends*; D016001:Confidence Intervals; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D009313:National Health Programs; D011446:Prospective Studies; D012737:Sex Factors; D018582:Sick Leave / Q000191:economics / Q000706:statistics & numerical data / Q000639:trends*; D013030:Spain; D055815:Young Adult