. 2015 Nov 6;10(11):e0142382. doi: 10.1371/journal.pone.0142382

Table 1. Weighted characteristics of the study population- NHANES (1999–2012).

		< 18 years			18+ years
		Number	%	SE	Number	%	SE
Sex	Male	13946	51.1	0.4	17887	48.7	0.3
	Female	13532	48.9	0.4	18757	51.3	0.3
Race	White	7498	57.0	1.4	16460	68.9	1.2
	Others	19980	43.0	1.4	20184	31.1	1.2
Poverty Income Ratio	PIR≤1	9043	24.5	0.7	7482	15.1	0.5
	PIR>1	16384	75.5	0.7	25962	84.9	0.5
Education	<High School				10136	19.6	0.5
	High School				7877	24.5	0.5
	>High School				15642	55.9	0.8
Smoking History	Ever Smoker				15697	47.3	0.6
	Never Smoker				17984	52.7	0.6
Alcohol Consumption	Current drinker				21462	74.4	0.7
	Non-current drinker				9315	25.6	0.7
Chronic Diseases	Yes	3778	14.5	0.4	22707	62.4	0.6
	No	23700	85.5	0.4	13937	37.6	0.6
		N	Mean	Range	N	Mean	Range
Age	(years)	27478	8.7	0–17	36644	45.5	18–85
BMI	(kg/m²)	22318	19.1	8–62.7	35798	27.6	13.2–130.2
Hemoglobin	(g/dL)	20317	13.4^*	6.4–19	34671	14.3^*	5.8–19.7
Mean cell hemoglobin	(pg)	20317	28.9	14.9–42.8	34671	30.6^*	14.7–60.8
Mean cell volume	(fL)	20317	84.4	50.7–106.5	34671	89.7^*	50.5–120.6
Hematocrit	(%)	20317	39.2	20.8–55.5	34671	41.9	19.7–59.9
Red cell count	(10⁶ cells/uL)	20317	4.6^*	2.5–7.3	34671	4.7	2.3–9.2
Platelet count	(10³ cells/uL)	20316	294.7^*	13–1000	34670	251.9^*	4–1000
Basophils number	(10³ cells/uL)	20305	0.04	0–2	34511	0.04	0–4.7
Eosinophils number	(10³ cells/uL)	20305	0.2	0–5.3	34511	0.2	0–8.4
Monocyte number	(10³ cells/uL)	20305	0.6^*	0.1–3.8	34550	0.5^*	0–10.2
Segmented neutrophils number	(10³ cells/uL)	20305	3.3^*	0.2–18.5	34551	4.0	0.1–83.1
Lymphocyte number	(10³ cells/uL)	20305	2.6	0.4–15.5	34551	2.0^*	0.4–89.7
Neutrophil to Lymphocyte ratio		20305	1.3^*	0.04–17.1	34551	2.0^*	0.009–28.7
White blood cell count	(10³ cells/uL)	20316	7.0^*	1.4–26.3	34670	6.9^*	1.5–100
C-reactive protein	(mg/dL)	14994	0.04^*	0.01–13.6	29440	0.2^*	0.01–29.6

Note: Geometric means were calculated (except for Age). SE = standard error.

*, Seasonal differences (winter-spring vs summer-fall, Wilcoxon tests) were statistically significant at p≤0.001 level. Statistics are based on weighted estimates accounting for the complex sampling design of NHANES. Percentages are not calculated directly on the absolute numbers presented in the table.