Table 1. Demographic features and caffeine consumption.

-	Patients		Controls		Statistic (P)
-	Mean/N	SD/%	Mean/N	SD/%
Age	41	12	40	14	ns
Females	43	66	44	67	ns
Current smoker	7	11	2	3	ns
Daily caffeine intake (mg)	259	126	100	90	<0.001
Use of caffeine-containing medications	26	40	4	6	<0.001
Consumption of energy drinks	7	11	0	-	0.007
Harmful caffeine use	9	14	0	-	<0.002
Hours of sleep	5.1	2.0	7.5	1.3	<0.001

ns = non statistically significant; SD = standard deviation.