TABLE 2—

Crude and Adjusted Proportions of Children Aged 6–19 Years Classified as Underhydrated, by Sociodemographic Group: National Health and Nutrition Examination Survey, United States, 2009–2012

Sociodemographic Group	No. (Weighted %)	OR (95% CI), Crude Models	P	OR (95% CI), Adjusted Model	P
Overall	2298 (54.5)
Age, y
6–11	1167 (55.5)	1.15 (1.00, 1.33)	.06	1.11 (0.97, 1.27)	.12
12–19	1131 (52.0)	1.00 (Ref)		1.00 (Ref)
Gender
Male	1336 (60.0)	1.75 (1.48, 2.06)	< .001	1.76 (1.49, 2.07)	< .001
Female	962 (46.3)	1.00 (Ref)		1.00 (Ref)
Race/ethnicity
Non-Hispanic White	615 (50.8)	1.00 (Ref)		1.00 (Ref)
Non-Hispanic Black	626 (58.7)	1.38 (1.09, 1.74)	.008	1.34 (1.04, 1.74)	.02
Hispanic	784 (56.7)	1.27 (1.00, 1.61)	.048	1.23 (0.96, 1.57)	.1
Other race, including multiracial	272 (55.7)	1.22 (0.91, 1.64)	.19	1.19 (0.89, 1.62)	.23
Incomea
Higher income	1239 (52.7)	1.00 (Ref)		1.00 (Ref)
Lower income	1059 (55.2)	1.10 (0.96, 1.27)	.17	1.05 (0.90, 1.22)	.54

Note. CI = confidence interval; OR =odds ratio. Underhydrated defined as urine osmolality ≥ 800 mOsm/kg. Crude models are of each individual demographic characteristic predicting urine osmolality, with no adjustment for covariates. Adjusted model includes all sociodemographic variables (age category, gender, race/ethnicity, income) simultaneously with time of examination.

^aLower income was operationalized by the National Health and Nutrition Examination Survey as income below 130% of the poverty line. Higher income was operationalized as income at or above 130% of the poverty line.