Dynamic Smoking Patterns and Risk of Parkinson Disease and All-Cause Mortality

The observed pattern of PD risk was suggested to be primarily associated with current smoking status rather than cumulative smoking exposure, as relapsed smokers and recent quitters, who had the same number of smoking time points, showed distinctly different risks. Furthermore, 1 time point (∼2 years) of short-term abstinence did not attenuate the protective association. Mortality was lowest in sustained quitters while recent quitters showed a marginal trend toward lower risk, supporting the benefit of early cessation. Interpretation should be cautious because smoking status was assessed at 3 time points, subsequent changes were unknown, and most participants were male.