[Skip to Content]
[Skip to Content Landing]
Views 428
Citations 0
Comment & Response
July 3, 2018

Professional Football Participation and Mortality

Author Affiliations
  • 1University of Nottingham, Nottingham, United Kingdom
JAMA. 2018;320(1):91-92. doi:10.1001/jama.2018.6705

To the Editor A well-defined exposure is essential for a cohort study to determine an association between the exposure and a specific outcome. A lower-dose exposure is only useful and statistically powerful when used to examine a dose-response relationship; used only as a control, it is likely to underestimate an association. An infamous example of misclassification of exposed and nonexposed groups and a subsequent null result was the Danish study assessing risk of brain tumors from mobile phones.1