title: Psychological symptoms and subsequent sickness absence.
abstract: OBJECTIVE
  Mental health problems are associated with sickness absence (SA). The present study aimed at establishing which symptoms-distress, depression, anxiety, or somatization-at which symptom levels were associated with SA frequency and duration. Moreover, a number of possible confounders or effect modifiers were taken into account.
  
  
  METHODS
  A survey was completed by 3,678 employees of a large Dutch telecom company. Symptoms were measured using the Four-Dimensional Symptom Questionnaire (4DSQ). SA data were registered by the company's occupational health service during the 12 months' period following the survey. Poisson regression was used to analyze the number of SA spells (SA frequency). Negative binomial regression was used to analyze the total number of SA days (SA duration).
  
  
  RESULTS
  In the bivariate analyses distress, depression, anxiety, and somatization impacted on SA frequency and duration. In the multivariate analyses, anxiety and depression turned out not to be directly associated with SA, suggesting that the effect of anxiety and depression was due to the association between anxiety/depression and distress/somatization. Regarding the SA frequency, the rate ratio for 'subclinical' distress was 1.13 (95% CI 1.03-1.25), for 'clinical' distress 1.26 (1.08-1.47), for 'subclinical' somatization 1.34 (1.23-1.46), and for 'clinical' somatization 1.69 (1.46-1.95). Regarding the SA duration, the count ratio for 'subclinical' distress was 1.15 (95% CI 0.91-1.44), for 'clinical' distress 1.50 (1.04-2.16), for 'subclinical' somatization 1.34 (1.10-1.64), and for 'clinical' somatization 1.45 (1.04-2.03).
  
  
  CONCLUSIONS
  Somatization and distress are key to understand why depression and anxiety are related to SA.
authors.affiliation: Department of General Practice, EMGO Institute for Health and Care Research, VU University Medical Center, Van der Boechorststraat 7, Amsterdam, The Netherlands. b.terluin@vumc.nl
authors.forename: Berend
authors.initials: B
authors.lastname: Terluin
authors.forename: Willem
authors.initials: W
authors.lastname: van Rhenen
authors.forename: Johannes R
authors.initials: JR
authors.lastname: Anema
authors.forename: Toon W
authors.initials: TW
authors.lastname: Taris
mesh_terms: D000041:Absenteeism; D000328:Adult; D001007:Anxiety / Q000175:diagnosis* / Q000523:psychology; D003863:Depression / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales; D018582:Sick Leave / Q000706:statistics & numerical data*; D013001:Somatoform Disorders / Q000175:diagnosis* / Q000523:psychology; D013315:Stress, Psychological / Q000175:diagnosis / Q000523:psychology; D011795:Surveys and Questionnaires