Table 1.

Characteristics of participants of the Parkinson’s Genes and Environment Study

Variables		Case (%) (n=808)	Control (%) (n=1623)	OR (95%CI)*	P *
Year of Birth (mean± SD)		1932±5	1932±5	-	-
Sex
	Female	189 (23.4%)	346 (21.3%)	-	-
	Male	619 (76.6%)	1277 (78.7%)	-	-
Caffeine intake
≤ median (≤ 216.54 mg)		452 (55.9%)	764 (47.1%)	ref.
> median (> 216.54 mg)		356 (44.1%)	859 (52.9%)	0.72(0.61-0.85)	<0.001
Smoking status
	Never	373 (46.2%)	569 (35.1%)	ref.
	Ever	404 (50.0%)	946 (58.3%)	0.68(0.57-0.81)	<0.001
	Current	31 (3.8%)	108 (6.6%)	0.47(0.31-0.71)	<0.001

^*Adjusted for year of birth, sex, caffeine intake and smoking status as appropriate.