Table 1.

Clinical characteristics of kidney stone formers

Age at first stone episode, years	35 (15–67)
Number of stone episodes
2-4, N (%)	70 (36)
5-10, N (%)	41 (21)
>10, N (%)	84 (43)
Stone type (number of patients)
Radiopaque stones, N (%)	154 (79)
Calcium oxalate
Idiopathic, N	55
Hemicolectomy/gastric bypass, N	5
Calcium phosphate
Idiopathic, N	7
Primary hyperparathyroidism, N	3
Unknown, N	84
Radiolucent stones, N (%)	20 (10)
Uric acid, N	13
2,8-Dihydroxyadenine, N	2
Unknown, N	5
Not determined, N (%)	21 (11)
ESWL, N (%)	131 (67)
Insertion of ureteral catheter, N (%)	84 (43)
Stone removal surgery, N (%)	10 (5)
Percutaneous, N	8
Open, N	2

Data are presented as median (range) for continuous variables and as number (%) for categorical variables

ESWL extracorporeal shock wave lithotripsy