title: Occupational exposure and risk of central nervous system demyelination.
abstract: Inconsistent evidence exists regarding the association between work-related factors and risk of multiple sclerosis (MS). We examined the association between occupational exposures and risk of a first clinical diagnosis of central nervous system demyelination (FCD), which is strongly associated with progression to MS, in a matched case-control study of 276 FCD cases and 538 controls conducted in Australia (2003-2006). Using a personal residence and work calendar, information on occupational history and exposure to chemicals and animals was collected through face-to-face interviews. Few case-control differences were noted. Fewer cases had worked as professionals (≥6 years) than controls (adjusted odds ratio (AOR) = 0.60, 95% confidence interval (CI): 0.37, 0.96). After further adjustment for number of children, cases were more likely to have ever been exposed to livestock than controls (AOR = 1.54, 95% CI: 1.03, 2.29). Among women, there was an increase in FCD risk associated with 10 or more years of exposure to livestock (AOR = 2.78, 95% CI: 1.22, 6.33) or 6 or more years of farming (AOR = 2.00, 95% CI: 1.23, 3.25; also adjusted for number of children). Similar findings were not evident among men. Thus, farming and exposure to livestock may be important factors in the development of FCD among women, with this finding further revealed after the confounding effect of parity or number of children is considered.
authors.forename: P C
authors.initials: PC
authors.lastname: Valery
authors.forename: R M
authors.initials: RM
authors.lastname: Lucas
authors.forename: D B
authors.initials: DB
authors.lastname: Williams
authors.forename: M P
authors.initials: MP
authors.lastname: Pender
authors.forename: C
authors.initials: C
authors.lastname: Chapman
authors.forename: A
authors.initials: A
authors.lastname: Coulthard
authors.forename: K
authors.initials: K
authors.lastname: Dear
authors.forename: T
authors.initials: T
authors.lastname: Dwyer
authors.forename: T J
authors.initials: TJ
authors.lastname: Kilpatrick
authors.forename: A J
authors.initials: AJ
authors.lastname: McMichael
authors.forename: I
authors.initials: I
authors.lastname: van der Mei
authors.forename: B V
authors.initials: BV
authors.lastname: Taylor
authors.forename: A-L
authors.initials: AL
authors.lastname: Ponsonby
mesh_terms: D000293:Adolescent; D000328:Adult; D000383:Agriculture / Q000706:statistics & numerical data*; D000818:Animals; D001315:Australia; D016022:Case-Control Studies; D003711:Demyelinating Diseases / Q000150:complications / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D058751:Livestock; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D009103:Multiple Sclerosis / Q000209:etiology; D016273:Occupational Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D009790:Occupations / Q000145:classification / Q000706:statistics & numerical data; D012307:Risk Factors; D017678:Sex Distribution; D011795:Surveys and Questionnaires; D013997:Time Factors; D055815:Young Adult
keywords: confounding; multiple sclerosis; occupational exposure; risk factors