Multivariable analysis adjusted for possible intermediate factors for the association between selected medical risk factors and cholangiocarcinoma by disease sites.

aOdds ratio (OR) and 95% confidence interval (CI) were derived using conditional logistic regression with age, sex, and the time of diagnosis (reference date for the controls) as matching variables.bOdds ratio (OR) and 95% confidence interval (CI) were derived using conditional logistic regression with age, sex, and the time of diagnosis (reference date for the controls) as matching variables and adjusted for possible intermediate factors.