Table 3.

Different risk factors for urinary tract infection

Risk Factors	Number	Without Infection		With Infection		χ2	P
		N	%	N	%
Sex						28.49	<.0001
Male	492	414	84.15	78	15.85
Female	314	214	68.15	100	31.85
Age groupa						9.35	0.0093
<40	252	194	76.98	58	23.02
40-60	409	334	81.66	75	18.34
>60	145	100	69.66	45	31.03
Stone site						54.06	<.0001
Single stone	615	516	83.90	99	16.10
Multiple sites	191	112	58.64	79	41.36
Obstruction						7.38	0.0066
Yes	394	291	73.86	103	26.14
No	412	337	81.80	75	18.20
Staghorn calculi						28.06	<.0001
Staghorn stones	64	33	51.56	31	48.44
Non-Staghorn stones	742	595	80.19	147	19.81
Smoking						3.44	0.0638
Yes	279	207	74.19	72	25.81
No	527	421	79.89	106	20.11
Alcohol Drinking						0.016	0.9006
Yes	293	229	78.16	64	21.84
No	513	399	77.78	114	22.22

^aAge group,

<40 versus 40-60,χ² = 3.08, P = 0.0793;

<40 versus >60, χ² = 2.12, P = 0.1451;

40-60 versus >60, χ² = 10.17, P = 0.0014;