This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
Abstract
Objective: To estimate the incidence and lifetime risk (LTR) of Parkinson disease (PD) in a large cohort of men.
Background: Age is the strongest risk factor for PD, but whether its incidence continues to increase after age 80 years remains unclear.
Methods: Prospective cohort of 21,970 US male physicians aged 40–84 years at baseline who did not report PD before study entry. Participants self-reported PD on yearly follow-up questionnaires, and all deaths were confirmed. We calculated incidence rates and cumulative incidence using a modified Kaplan–Meier analysis. LTR was estimated by adjusting cumulative incidence for competing risks of death.
Results: Five hundred sixty-three cases of PD were identified over 23 years of follow-up. The crude incidence rate of PD was 121 cases/100,000 person-years. Age-specific incidence rates increased sharply beginning at age 60 years, peaked in those aged 85–89 years, and declined beginning at age 90 years. Cumulative incidence substantially overestimated the long-term risk of PD, particularly in those aged 80 years and older. Cumulative incidence was 9.9% (95% confidence interval [CI] 8.48%–11.30%) from ages 45 to 100 years, whereas LTR for the same period was 6.7% (95% CI 6.01%–7.43%). The incidence and LTR of PD decreased with increasing exposure to smoking.
Conclusions: Our study provides evidence that the incidence of Parkinson disease (PD) in men increases through age 89 years. Whether the subsequent decline represents a true decrease in risk remains to be established. A history of smoking substantially decreased the incidence and lifetime risk of PD. Incidence studies that do not adjust for competing risks of death may overestimate the true risk of PD in the elderly.
Glossary
- AD=
- Alzheimer disease;
- CI=
- confidence interval;
- LTR=
- lifetime risk;
- PD=
- Parkinson disease;
- PHS=
- Physicians' Health Study.
AAN Members
We have changed the login procedure to improve access between AAN.com and the Neurology journals. If you are experiencing issues, please log out of AAN.com and clear history and cookies. (For instructions by browser, please click the instruction pages below). After clearing, choose preferred Journal and select login for AAN Members. You will be redirected to a login page where you can log in with your AAN ID number and password. When you are returned to the Journal, your name should appear at the top right of the page.
AAN Non-Member Subscribers
Purchase access
Letters: Rapid online correspondence
REQUIREMENTS
You must ensure that your Disclosures have been updated within the previous six months. Please go to our Submission Site to add or update your Disclosure information.
Your co-authors must send a completed Publishing Agreement Form to Neurology Staff (not necessary for the lead/corresponding author as the form below will suffice) before you upload your comment.
If you are responding to a comment that was written about an article you originally authored:
You (and co-authors) do not need to fill out forms or check disclosures as author forms are still valid
and apply to letter.
Submission specifications:
- Submissions must be < 200 words with < 5 references. Reference 1 must be the article on which you are commenting.
- Submissions should not have more than 5 authors. (Exception: original author replies can include all original authors of the article)
- Submit only on articles published within 6 months of issue date.
- Do not be redundant. Read any comments already posted on the article prior to submission.
- Submitted comments are subject to editing and editor review prior to posting.
