title: Long-term persistence of knee pain and occupational exposure in two large prospective cohorts of workers.
abstract: BACKGROUND
  The persistence of knee pain (KP) and its relationship with occupational factors were investigated in two prospective cohorts of French workers: retirees of the Gazel cohort and workers in the Cosali cohort.
  
  
  METHODS
  KP was defined according to the Nordic questionnaire (>1 day in the last year), and the information was extracted from two questionnaires in 2006 and 2012 for the Gazel cohort, and in 2002-2005 and 2007-2010 for the Cosali cohort. The personal and occupational factors and the severity of KP were measured at baseline. Of the 4590 members of the Gazel cohort with KP at baseline, 4140(90.2%) were followed up, as were 637(63.1%) members of the Cosali cohort. Logistic models were used to evaluate associations (ORs) between occupational exposure and the persistence of KP separately by sex, adjusted on indicators of severity of KP.
  
  
  RESULTS
  KP was no longer present at follow-up for 38.3% of Gazel men and 46.0% of Cosali men (33.4% of Gazel women and 50.6% of Cosali women). The persistence of KP in men was associated with carrying or handling heavy loads on univariate analyses and with kneeling on multivariate analyses, with ORs of 1.3(1.0-1.6) (Gazel) and 1.6(1.0-2.6) (Cosali). Climbing stairs was not significantly associated with the persistence of knee pain among men. The persistence of KP in women was not significantly associated with such occupational exposure.
  
  
  CONCLUSIONS
  This study highlights the role of occupational factors in the persistence of KP for men, in particular kneeling and handling/carrying loads.
authors.affiliation: UMS011 Inserm, Université Versailles St-Quentin, Population-Based Epidemiological Cohorts, Hôpital P, Brousse - bat 15/16 RDC Gauche, 16 av Paul Vaillant Couturier, 94807 Villejuif Cedex, France. eleonore.herquelot@inserm.fr.
authors.forename: Eléonore
authors.initials: E
authors.lastname: Herquelot
authors.forename: Julie
authors.initials: J
authors.lastname: Bodin
authors.forename: Audrey
authors.initials: A
authors.lastname: Petit
authors.forename: Catherine
authors.initials: C
authors.lastname: Ha
authors.forename: Annette
authors.initials: A
authors.lastname: Leclerc
authors.forename: Marcel
authors.initials: M
authors.lastname: Goldberg
authors.forename: Marie
authors.initials: M
authors.lastname: Zins
authors.forename: Yves
authors.initials: Y
authors.lastname: Roquelaure
authors.forename: Alexis
authors.initials: A
authors.lastname: Descatha
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D005602:France / Q000453:epidemiology; D006801:Humans; D007719:Knee Joint / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D010146:Pain / Q000175:diagnosis* / Q000453:epidemiology*; D011446:Prospective Studies; D013997:Time Factors; D055815:Young Adult