title: Identifying gender differences in reported occupational information from three US population-based case-control studies.
abstract: OBJECTIVE
  Growing evidence suggests that gender-blind assessment of exposure may introduce exposure misclassification, but few studies have characterised gender differences across occupations and industries. We pooled control responses to job-specific, industry-specific and exposure-specific questionnaires (modules) that asked detailed questions about work activities from three US population-based case-control studies to examine gender differences in work tasks and their frequencies.
  
  
  METHODS
  We calculated the ratio of female-to-male controls that completed each module. For four job modules (assembly worker, machinist, health professional, janitor/cleaner) and for subgroups of jobs that completed those modules, we evaluated gender differences in task prevalence and frequency using χ(2) and Mann-Whitney U tests, respectively.
  
  
  RESULTS
  The 1360 female and 2245 male controls reported 6033 and 12 083 jobs, respectively. Gender differences in female:male module completion ratios were observed for 39 of 45 modules completed by ≥20 controls. Gender differences in task prevalence varied in direction and magnitude. For example, female janitors were significantly more likely to polish furniture (79% vs 44%), while male janitors were more likely to strip floors (73% vs 50%). Women usually reported more time spent on tasks than men. For example, the median hours per week spent degreasing for production workers in product manufacturing industries was 6.3 for women and 3.0 for men.
  
  
  CONCLUSIONS
  Observed gender differences may reflect actual differences in tasks performed or differences in recall, reporting or perception, all of which contribute to exposure misclassification and impact relative risk estimates. Our findings reinforce the need to capture subject-specific information on work tasks.
authors.affiliation: Occupational and Environmental Epidemiology, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland, USA.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Locke
authors.affiliation: Occupational and Environmental Epidemiology, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland, USA.
authors.forename: Joanne S
authors.initials: JS
authors.lastname: Colt
authors.affiliation: Stewart Exposure Assessments, LLC, Arlington, Virginia, USA.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Stewart
authors.affiliation: New Hampshire Department of Health and Human Services, Division of Public Health Services, Bureau of Public Health Statistics and Informatics, Concord, New Hampshire, USA.
authors.forename: Karla R
authors.initials: KR
authors.lastname: Armenti
authors.affiliation: Occupational and Environmental Epidemiology, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland, USA.
authors.forename: Dalsu
authors.initials: D
authors.lastname: Baris
authors.affiliation: Occupational and Environmental Epidemiology, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland, USA.
authors.forename: Aaron
authors.initials: A
authors.lastname: Blair
authors.affiliation: Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
authors.forename: James R
authors.initials: JR
authors.lastname: Cerhan
authors.affiliation: The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Wong-Ho
authors.initials: WH
authors.lastname: Chow
authors.affiliation: Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, USA.
authors.forename: Wendy
authors.initials: W
authors.lastname: Cozen
authors.affiliation: Department of Public Health Sciences, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Faith
authors.initials: F
authors.lastname: Davis
authors.affiliation: Department of Environmental and Occupational Health, Drexel University School of Public Health, Philadelphia, Pennsylvania, USA.
authors.forename: Anneclaire J
authors.initials: AJ
authors.lastname: De Roos
authors.affiliation: Occupational and Environmental Epidemiology, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland, USA.
authors.forename: Patricia
authors.initials: P
authors.lastname: Hartge
authors.affiliation: Department of Community and Family Medicine, Dartmouth Medical School, Lebanon, New Hampshire, USA.
authors.forename: Margaret R
authors.initials: MR
authors.lastname: Karagas
authors.affiliation: Vermont Department of Health, Burlington, Vermont, USA.
authors.forename: Alison
authors.initials: A
authors.lastname: Johnson
authors.affiliation: Occupational and Environmental Epidemiology, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland, USA.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Purdue
authors.affiliation: Occupational and Environmental Epidemiology, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland, USA.
authors.forename: Nathaniel
authors.initials: N
authors.lastname: Rothman
authors.affiliation: Department of Family Medicine and Public Health Sciences, Wayne State University, Detroit, Michigan, USA.
authors.forename: Kendra
authors.initials: K
authors.lastname: Schwartz
authors.affiliation: Maine Cancer Registry, Augusta, Maine, USA.
authors.forename: Molly
authors.initials: M
authors.lastname: Schwenn
authors.affiliation: Department of Family Medicine and Public Health Sciences, Wayne State University, Detroit, Michigan, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Severson
authors.affiliation: Occupational and Environmental Epidemiology, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland, USA.
authors.forename: Debra T
authors.initials: DT
authors.lastname: Silverman
authors.affiliation: Occupational and Environmental Epidemiology, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland, USA.
authors.forename: Melissa C
authors.initials: MC
authors.lastname: Friesen
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D005783:Gender Identity; D019981:Health Care Sector; D006796:Household Work; D006801:Humans; D007221:Industry; D008297:Male; D066192:Manufacturing Industry; D008875:Middle Aged; D016273:Occupational Exposure / Q000032:analysis*; D009790:Occupations; D012737:Sex Factors; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires; D014937:Work; D055815:Young Adult
keywords: case-control studies; occupational exposure; occupational health; population-based studies