title: Prognostic factors for duration of sick leave in patients sick listed with acute low back pain: a systematic review of the literature.
abstract: BACKGROUND
  The percentages of patients with acute low back pain (LBP) that go on to a chronic state varies between studies from 2% to 34%. In some of these cases low back pain leads to great costs.
  
  
  OBJECTIVE
  To evaluate the evidence for prognostic factors for return to work among workers sick listed with acute LBP.
  
  
  METHODS
  Systematic literature search with a quality assessment of studies, assessment of levels of evidence for all factors, and pooling of effect sizes.
  
  
  RESULTS
  Inclusion of studies in the review was restricted to inception cohort studies of workers with LBP on sick leave for less than six weeks, with the outcome measured in absolute terms, relative terms, survival curve, or duration of sick leave. Of the studies, 18 publications (14 cohorts) fulfilled all inclusion criteria. One low quality study, four moderate quality studies, and nine high quality studies were identified; 79 prognostic factors were studied and grouped in eight categories for which the evidence was assessed.
  
  
  CONCLUSIONS
  Specific LBP, higher disability levels, older age, female gender, more social dysfunction and more social isolation, heavier work, and receiving higher compensation were identified as predictors for a longer duration of sick leave. A history of LBP, job satisfaction, educational level, marital status, number of dependants, smoking, working more than 8 hour shifts, occupation, and size of industry or company do not influence duration of sick leave due to LBP. Many different constructs were measured to identify psychosocial predictors of long term sick leave, which made it impossible to determine the role of these factors.
authors.affiliation: Institute for Research in Extramural Medicine and Department of Public and Occupational Health, VU University Medical Center, Amsterdam, Netherlands. i.a.steenstra@amc.uva.nl
authors.forename: I A
authors.initials: IA
authors.lastname: Steenstra
authors.forename: J H
authors.initials: JH
authors.lastname: Verbeek
authors.forename: M W
authors.initials: MW
authors.lastname: Heymans
authors.forename: P M
authors.initials: PM
authors.lastname: Bongers
mesh_terms: D000208:Acute Disease; D000367:Age Factors; D015331:Cohort Studies; D004185:Disability Evaluation; D018450:Disease Progression; D006801:Humans; D017116:Low Back Pain / Q000473:pathology* / Q000523:psychology*; D011379:Prognosis; D012737:Sex Factors; D018582:Sick Leave; D012934:Social Isolation; D014940:Work Schedule Tolerance