Conflict of interest statement: The authors report no conflicts of interest.
Parkinson's Disease and Occupation: Differences in Associations by Case Identification Method Suggest Referral Bias
Article first published online: 25 OCT 2013
© 2013 Wiley Periodicals, Inc.
American Journal of Industrial Medicine
Volume 57, Issue 2, pages 163–171, February 2014
How to Cite
Teschke, K., Marion, S. A., Tsui, J. K.C., Shen, H., Rugbjerg, K. and Harris, M. A. (2014), Parkinson's Disease and Occupation: Differences in Associations by Case Identification Method Suggest Referral Bias. Am. J. Ind. Med., 57: 163–171. doi: 10.1002/ajim.22272
- Issue published online: 9 JAN 2014
- Article first published online: 25 OCT 2013
- Manuscript Accepted: 30 SEP 2013
- WorkSafeBC. Grant Numbers: RS2000/01-010, RS2007-OG05
- Medical Research Council (MRC 1999)
- Pacific Parkinson's Research Institute
- Michael Smith Foundation for Health Research
- Canadian Institutes of Health Research/Public Health Agency of Canada
- Parkinson's disease;
- occupational exposure;
- selection bias
We used a population-based sample of 403 Parkinson's disease cases and 405 controls to examine risks by occupation. Results were compared to a previous clinic-based analysis.
With censoring of jobs held within 10 years of diagnosis, the following had significantly or strongly increased risks: social science, law and library jobs (OR = 1.8); farming and horticulture jobs (OR = 2.0); gas station jobs (OR = 2.6); and welders (OR = 3.0). The following had significantly decreased risks: management and administration jobs (OR = 0.70); and other health care jobs (OR = 0.44).
These results were consistent with other findings for social science and farming occupations. Risks for teaching, medicine and health occupations were not elevated, unlike our previous clinic-based study. This underscores the value of population-based over clinic-based samples. Occupational studies may be particularly susceptible to referral bias because social networks may spread preferentially via jobs. Am. J. Ind. Med. 57:163–171, 2014. © 2013 Wiley Periodicals, Inc.