Table 2.

Variable assignment for unordered multi-classification logistic regression.

Factors	Variables	Variable assignment
Type of stone	Y	CaOx = 0, CaP = 1, IS = 2, UA = 3
Gender	X1	Female = 0, Male = 1
Age	X2	1–30 = 1,31–60 = 2,61–90 = 3
FH	X3	NO- FH = 1, FH = 0
UTI	X4	NO- UTI = 1, UTI = 0
HUA	X5	NO- HUA = 1, HUA = 0
Stone location	X6	Urethra = 1, Bladder = 2, Ureter = 3, Kidney = 4