Table 1.

Demographic characteristics of Parkinson's disease (PD) cases and controls.

Characteristics	Cases = 583		Controls = 553
Gender (n, %)∗
Female	320	54.9	286	51.7
Male	263	45.1	267	48.3
Age at collection (mean, SD)†	65.10	8.90	65.37	9.03
Age at onset (n, %)
<50	131	22.5	n.a.	n.a.
≧50	452	77.5	n.a.	n.a.

All the subjects were ethnic Hans; ^∗PD compared with controls by gender: P > 0.05; ^†PD compared with controls by age: P > 0.05; n.a.: not applicable.