Table 3.

Association between log plasma levels of caffeine and its metabolites and the reported caffeine consumption in CoLaus|PsyCoLaus

		Caffeine + paraxanthine + theophylline plasma levelsa
	Predictors	Estimates (95% confidence interval)	p-value
Caffeinated beverage consumption (N = 4423)	Intercept (6 or more cups per day)	6.93 (6.69; 7.17)	< 10 − 3
	Caffeinated beverage b
	None per day	−1.43 (−1.64; −1.22)	< 10 − 3
	1–3 per day	−0.31 (−0.48; −0.14)	< 10 − 3
	4–6 per day	−0.04 (−0.22; 0.14)	0.65

Model was adjusted for age and smoking

^aLog transformed

^bCompared to those who reported consuming more than 6 cups per day