title: Rheumatoid arthritis among women in the Agricultural Health Study: risk associated with farming activities and exposures.
abstract: OBJECTIVE
  Farming has been associated with increased risk of rheumatoid arthritis (RA) in some studies, but specific causes have not been identified. We studied risk factors for RA in the Agricultural Health Study, a cohort of over 57,000 licensed pesticide applicators and their spouses.
  
  
  METHODS
  We used a nested case-control design, limited to female participants. Physician-confirmed cases (n = 135) were matched to five controls each (n = 675) by birth date. We used logistic regression, adjusting for birth date and state to examine associations, as estimated by odds ratios (OR) and 95% confidence intervals (CI).
  
  
  RESULTS
  Risk of RA was not associated with mixing or applying pesticides overall or with any pesticide class, nor did it vary by number of days or years of use. Certain pesticides were associated with small nonsignificantly increased risks, including lindane (OR = 1.8, 95% CI: 0.6-5.0). RA risk was associated with welding (OR = 2.1, 95% CI: 0.8-5.4), albeit imprecisely, but not with solvents or sunlight.
  
  
  CONCLUSIONS
  We did not identify any strong risk factors for RA. Because of the severe disability associated with this relatively common disease, further investigation into causes is warranted both in the Agricultural Health Study and elsewhere.
authors.affiliation: University of Washington Department of Epidemiology and Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA. deroos@u.washington.edu
authors.forename: Anneclaire J
authors.initials: AJ
authors.lastname: De Roos
authors.forename: Glinda S
authors.initials: GS
authors.lastname: Cooper
authors.forename: Michael C
authors.initials: MC
authors.lastname: Alavanja
authors.forename: Dale P
authors.initials: DP
authors.lastname: Sandler
mesh_terms: D000328:Adult; D000368:Aged; D000383:Agriculture; D001172:Arthritis, Rheumatoid / Q000209:etiology*; D016022:Case-Control Studies; D015331:Cohort Studies; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D008875:Middle Aged; D016017:Odds Ratio; D010575:Pesticides / Q000506:poisoning*; D012307:Risk Factors; D018454:Spouses
chemical_list: D010575:Pesticides