Occupation and Parkinson disease in Women's Health Initiative Observational Study
IntroductionThere is a lack of consistency in associations between workplace factors and risk of Parkinson disease (PD), and paucity of such data on women. We took a classic occupational epidemiology approach that assesses associations with occupational groups in order to derive insights about potential occupation-specific exposures that may be causal. MethodsThe Womens Health Initiative (WHI-OS) is a prospective cohort that enrolled 91,627 postmenopausal women, 50 to 79 years of age from 10/01/93 to 12/31/98, at 40 clinical centers across the US with average follow-up of 11 years, who reported up to three paid jobs held the longest since age 18; these jobs were coded and duration of employment calculated. We defined the case by self-report of doctor-diagnosed PD (at baseline or follow-up), death attributed to PD, or medication consistent with PD. ResultsAmong 2,590 cases, we report evidence of excess risk among "counselors, social workers, and other community and social service specialists". There was a suggestion of increase in risk among post-secondary teachers, and "building and grounds cleaning and maintenance". There was also evidence of deficit in risk among women who worked in sales. Results with ever-employed and duration were similar, except for evidence of excess of risk among "health technologists and technicians" with more than 20 years of employment. Longer duration of life on a farm was associated with higher risk. ConclusionOur findings paint a largely reassuring picture of occupational risks for PD among US women, especially for trades largely unaffected by recent technological advances.