title: Meta-analyses of non-Hodgkin's lymphoma and farming.
abstract: OBJECTIVE
  This study examined the association between non-Hodgkin's lymphoma (NHL) and farming.
  
  
  METHODS
  A series of meta-analyses of peer-reviewed studies was performed using 36 studies published between 1982 and 1997. Prior to the meta-analyses, all the studies were reviewed and evaluated for heterogeneity and publication bias. Combined relative risks (RR) were calculated using the random effect model.
  
  
  RESULTS
  The combined RR was 1.10 [95% confidence interval (95% CI) 1.03-1.19] for all the studies and 0.93 (95% CI 0.82-1.06) for studies involving female farmers. Significant heterogeneity was detected for study design and country of study among the studies. Significantly elevated RR values were obtained for case-referent studies (combined RR 1.19, 95% CI 1.06-1.33) and for studies conducted on farmers residing in the United States (combined RR 1.26, 95% CI 1.15-1.37). These findings were not influenced by a publication bias.
  
  
  CONCLUSIONS
  The findings suggest that male farmers residing in the United States have a slightly elevated risk of contracting NHL. Commonly experienced exposures that might contribute to the occurrence of NHL in this group include infectious microorganisms, herbicides, and insecticides.
authors.affiliation: Medical College of Ohio, Toledo 43699-0008, United States. skhuder@vortex.mco.edu
authors.forename: S A
authors.initials: SA
authors.lastname: Khuder
authors.forename: E A
authors.initials: EA
authors.lastname: Schaub
authors.forename: J E
authors.initials: JE
authors.lastname: Keller-Byrne
mesh_terms: D000328:Adult; D000382:Agricultural Workers' Diseases / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D016273:Occupational Exposure / Q000009:adverse effects; D017594:Publication Bias; D012306:Risk; D014481:United States