Recall bias?
Commenting for this news organization, Rebecca Gilbert, MD, PhD, chief scientific officer, American Parkinson Disease Association (APDA), noted that the authors “are very frank about the limitations of this approach [illustrative cases] as proof of causation between PD and TCE exposure.”
Another limitation is that TCE exposure is very common, “as argued in the paper.” But “most people with exposure do not develop PD,” Dr. Gilbert pointed out. “By probing the TCE exposure of those who already have PD, there is a danger of recall bias.”
Dr. Gilbert, associate professor of neurology at NYU Langone Health, who was not involved with the study, acknowledged that the authors “present their work as hypothesis and clearly state that more work is needed to understand the connection between TCE and PD.”
In the meantime, however, there are “well-established health risks of TCE exposure, including development of various cancers,” she said. Therefore, the authors’ goals appear to be educating the public about known health risks, working to clean up known sites of contamination, and advocating to ban future use of TCE.
These goals “do not need to wait for [proof of] firm causation between TCE and PD,” she stated.
Dr. Dorsey reported he has received honoraria for speaking at the American Academy of Neurology and at multiple other societies and foundations and has received compensation for consulting services from pharmaceutical companies, foundations, medical education companies, and medical publications; he owns stock in several companies. The other authors’ disclosures can be found in the original paper. Dr. Gilbert is employed by the American Parkinson Disease Association and Bellevue Hospital Center in New York City.
A version of this article first appeared on Medscape.com.