Table 3.

Limits of agreement of research protocol and WIC usual care measurements and estimated mean bias of WIC usual care measurements, overall and by child factors and source

Factor	N (%)	Height (cm)	Height for Age Percentile	Weight (kg)	Weight for Age Percentile	BMI (kg/m2)	BMI Percentile
		95% limits of agreement
Overall	287 (100%)	(−2.1, 3.3)	(−15, 23)	(−0.7, 0.8)	(−9, 11)	(−1.3, 1.0)	(−21, 18)
		Estimated mean bias
Overall (with 95% confidence intervals)	287 (100%)	0.6 (0.4,0.8)	4.0 (2.7, 5.2)	0.05 (−0.01,0.11)	0.8 (0.2,1.5)	−0.15 (−0.23,−0.07)	−2.3 (−3.6,−0.9)
Age of child
2–3 years	87 (30%)	0.4	3.5	0.02	0.6	−0.1	−2.6
3–4 years	103 (36%)	0.7	4.8	0.04	0.6	−0.2	−3.7
4–5 years	97 (34%)	0.7	3.5	0.10	1.3	−0.1	−0.4
P-value		NS	NS	NS	NS	NS	NS
Sex of child
Female	136 (47%)	0.5	3.1	0.04	1.1	−0.1	−1.2
Male	151 (53%)	0.7	4.7	0.07	0.6	−0.2	−3.2
P-value		NS	NS	NS	NS	NS	NS
Race/ethnicity of child
African American	23 (8%)	1.0	5.3	0.07	0.4	−0.3	−2.4
Asian*	7 (2%)	--	--	--	--	--	--
Hispanic	230 (80%)	0.6	3.8	0.07	1.0	−0.1	−2.0
Non-Hispanic white	27 (9%)	0.6	3.2	−0.09	− 0.8	−0.3	−4.1
P-value		NS	NS	NS	NS	NS	NS
Preferred language of family
English	146 (51%)	0.6	3.8	0.04	0.2	−0.2	−2.7
Spanish	141 (49%)	0.5	4.1	0.07	1.5	−0.1	−1.8
P-value		NS	NS	NS	NS	NS	NS
Child height
<100 cm	167 (58%)	0.6	4.8	0.07	1.2	−0.1	−2.5
≥100 cm	120 (42%)	0.6	2.7	0.03	0.3	−0.2	−1.9
P-value		NS	NS	NS	NS	NS	NS
Child weight
<16 kg	137 (48%)	0.5	4.6	0.08	1.3	−0.1	−2.4
≥16 kg	150 (52%)	0.7	3.4	0.03	0.4	−0.2	−2.2
P-value		NS	NS	NS	NS	NS	NS
Child BMI
<16.5 kg/m2	126 (44%)	0.3	2.2	0.08	1.6	0.01	−0.4
≥16.5 kg/m2	161 (56%)	0.9	5.3	0.03	0.2	−0.28	−4.0
P-value	NS	< .05	< .05	NS	< .05	< .001	< .05
Child BMI percentile
<75th	140 (49%)	0.4	3.2	0.10	1.69	−0.02	−1.0
≥ 75th	147 (51%)	0.8	4.7	0.01	0.04	−0.28	−3.5
P-value	NS	< .05	NS	NS	< .05	< .05	NS
Source of WIC values
In-clinic	268 (93%)	0.6	4.1	0.07	1.1	−0.1	−1.9
Provider record	19 (7%)	0.4	2.4	−0.23	−2.1	−0.4	−7.1
P-value	NS	NS	NS	< .05	< .05	NS	NS

Positive mean bias values indicate that WIC measurements were overestimates on average; negative mean bias values indicate that WIC measurements were underestimates on average. P-values obtained from likelihood ratio tests comparing models with and without an interaction between rater and factor.

NS: difference is not statistically significant

^*Not estimated due to small sample size.