. 2013 May 15;98(1):189–196. doi: 10.3945/ajcn.112.051508

TABLE 2.

Multiple linear regression analysis of fluid consumption (g/d) and dietary sodium intake (390 mg/d) in US children and adolescents aged 2–18 y by age group and sex: NHANES 2005–2006 (n = 6400)¹

		Age group
		2–5 y		6–11 y		12–18 y
Model	Total	M	F	M	F	M	F
1a
n	6400	856	773	1000	1050	1374	1347
β (95% CI), P	101 (78, 123), <0.001	43 (26, 61), <0.001	68 (52, 84), <0.001	52 (39, 64), <0.001	40 (31, 49), <0.001	110 (73, 146), <0.001	49 (14, 85), <0.01
R²	0.17, <0.001	0.05, <0.001	0.11, <0.001	0.07, <0.001	0.05, <0.001	0.17, <0.001	0.05, <0.01
1b
n	6400	856	773	1000	1050	1374	1347
β (95% CI), P	74 (57, 92), <0.001	44 (26, 63), <0.001	65 (49, 82), <0.001	46 (33, 60), <0.001	40 (32, 48), <0.001	108 (75, 141), <0.001	55 (17, 93), <0.01
R²	0.28, <0.001	0.05, <0.01	0.13, <0.001	0.12, <0.001	0.11, <0.001	0.23, <0.001	0.13, <0.01
1c
n	5677	808	729	932	986	1198	1024
β (95% CI), P	66 (48, 84), <0.001	44 (25, 62), <0.001	67 (51, 83), <0.001	45 (31, 60), <0.001	39 (31, 47), <0.001	95 (61, 130), <0.001	57 (10, 104), <0.05
R²	0.29, <0.001	0.05, <0.01	0.15, <0.001	0.12, <0.001	0.11, <0.001	0.23, <0.001	0.14, <0.01

In all models, the dependent variable was fluid consumption (g/d), and the independent variable was sodium intake (390 mg/d). Model 1a was unadjusted. Model 1b was adjusted for age, sex, race-ethnic group, socioeconomic status, BMI z score, and season. Age and sex were not adjusted for in the stratified models. Model 1c was adjusted as for model 1b and for the number of times engaged in vigorous activity per week; the analysis was completed in a subsample of participants with physical activity data available (n = 5677). For R² values, the second value in each cell represents the F test of the overall significance of the regression model.