Table 3. Logical regression analysis of factors related to the prevalence rate of kidney stones.

Characteristic	Univariate analysis			Multivariate analysisa
	OR (95% CI)	P value		OR (95% CI)	P value
Gender
Male	1 (reference)			1 (reference)
Female	0.52 (0.43–0.63)	<0.001		0.55 (0.45–0.68)	<0.001
Age, years
20–39	1 (reference)
40–59	1.97 (1.49–2.60)	<0.001		1.65 (1.23–2.22)	0.001
60+	2.82 (2.16–3.66)	<0.001		1.84 (1.32–2.56)	<0.001
Race
Non-Hispanic white	1 (reference)
Non-Hispanic black	0.49 (0.37–0.65)	<0.001		0.47 (0.35–0.64)	<0.001
Mexican American	0.54 (0.41–0.72)	<0.001		0.63 (0.47–0.86)	0.003
Other Hispanic	0.72 (0.52–0.99)	0.042		0.78 (0.57–1.09)	0.142
Other	0.40 (0.22–0.75)	0.004		0.46 (0.25–0.87)	0.016
Marital status
Married	1 (reference)
Unmarried	0.88 (0.72–1.08)	0.217
Other	0.65 (0.42–1.00)	0.050
Education
Less than high school	1 (reference)
High school or equivalent	1.04 (0.81–1.33)	0.777
College or above	0.85 (0.68–1.07)	0.168
Hypertension
Yes	1 (reference)			1 (reference)
No/unknown	0.55 (0.45–0.67)	<0.001		0.74 (0.59–0.91)	0.005
Diabetes
Yes	1 (reference)			1 (reference)
No/unknown	0.51 (0.40–0.65)	<0.001		0.68 (0.52–0.88)	0.004
BMI (kg/m2)
Normal (<25.0)	1 (reference)			1 (reference)
Overweight (25.0–29.9)	1.30 (1.01–1.68)	0.044		–	0.573
Obese (≥30.0)	1.52 (1.18–1.94)	0.001		–	0.113
eGFR (mL/min/1.73 m2)
<90	1 (reference)			1 (reference)
≥90	0.49 (0.40–0.59)	<0.001		0.76 (0.60–0.97)	0.029
Urine specific gravity (g/mL)
<1.013	1 (reference)			1 (reference)
1.013–1.020	1.41 (0.98–2.03)	0.066		1.31 (0.90–1.91)	0.155
>1.020	1.65 (1.13–2.41)	0.009		1.71 (1.16–2.54)	0.007

^a, model was adjusted by gender, age, race, hypertension, diabetes, BMI, eGFR and urine specific gravity. BMI, body mass index; eGFR, estimated glomerular filtration rate.