GPT and gallstones: A predictive model was constructed based on these factors: logit(P) = -5.109 + 2.007x1 + 1.175x2 + 3.479x3 + 1.412x4 + 2.199x5 + 2.473x6 (where x1-x6 represent age, location of gallstones, ultrasonographic indication of common bile duct dilation, ALT, GGT, DBIL, respectively).