Table 1.
Clinical characteristics of patients presenting with first-time stone episodes according to sex and age

	Total (n=1426)			Male (n=903)			Female (n=523)
	≤60 years	>60 years	p	≤60 years	>60 years	p	≤60 years	>60 years	p
	No. of patients (%)	1261 (88.4)	165 (11.6)		841 (93.1)	62 (6.9)		420 (80.3)	103 (19.7)
Mean age ± SD (years)	42.4 ± 10.5	65.5 ± 4.2	<0.001	40.8 ± 10.2	64.6 ± 3.7	<0.001	45.4 ± 10.5	66.0 ± 4.5	<0.001
BMI ± SD (kg/m2)	24.0 ± 3.2	24.3 ± 3.2	0.302	24.3 ± 3.2	24.5 ± 2.5	0.758	23.5 ± 3.1	24.2 ± 3.6	0.031
Family history of stones (%)			0.772			0.285			0.440
Yes	236 (18.7)	29 (17.8)		157 (18.7)	15 (24.2)		79 (18.8)	16 (15.5)
No	1025 (81.3)	134 (82.2)		684 (81.3)	47 (75.8)		341 (81.2)	87 (84.5)
Diabetes mellitus (%)			0.003			<0.001			0.229
Yes	27 (2.1)	11 (6.7)		19 (2.3)	7 (11.3)			8 (1.9)	4 (3.9)
No	1234 (97.9)	154 (93.3)		822 (97.7)	55 (88.7)		412 (98.1)	99 (96.1)
Hypertension (%)			0.002			0.005			0.172
Yes	57 (4.5)	17 (10.3)		32 (3.8)	7 (11.3)		395 (94.0)	93 (90.3)
No	1204 (95.5)	148 (89.7)		809 (96.2)	55 (88.7)		25 (6.0)	10 (9.7)
Stone size (mm)	7.6 ± 6.6	9.8 ± 7.6	0.001	7.7 ± 6.4	8.2 ± 5.9	0.535	7.3 ± 7.1	10.7 ± 8.3	<0.001

Data are presented as the mean ± standard deviation or the number of patients, with the percentage in parentheses. The patients’ numbers for category of family history and stone episodes included only data from responders of questions.