Table 3.

Odds ratio and 95% confidence interval of cumulative duration of thiazolidinediones use associated with colorectal cancer.

Variable	Case number /control number	Crude OR	(95% CI)	Adjusted OR†	(95% CI)
Never used thiazolidinediones as a reference	16431/16400	1.00	(reference)	1.00	(reference)
Cumulative duration of thiazolidinediones use (increase every one year)	3787/3818	1.00	(0.99, 1.001)	0.998	(0.997, 0.999)

^†Variables which were statistically associated with colorectal cancer in a univariable model were further included in a multivariable model. Only other anti-diabetic drugs and alcohol-related disease were included for adjustment.