Table 3.

Evaluation of standard deviation of anthropometric indices overall and by age group, by the quality of age ascertainment (based on percentage of children with exact date of birth)

Indicator		Birthday > 90% (mean)	Birthday 10–90% (mean)	Birthday < 10% (mean)
WHZ	N	272	309	131
	Children 6–59 m	1.03	1.06	1.08
	Children 6–23 m	1.08	1.11	1.15
	Children 24–59 m	0.99	1.02	1.03
	Differencea	0.09***	0.10***	0.12***
	Correlationb	0.62***	0.51***	0.53***
	% youngerc better	5.2%	6.9%	2.3%
WAZ	N	272	309	131
	Children 6–59 m	1.02	1.05	1.05
	Children 6–23 m	1.10	1.14	1.14
	Children 24–59 m	0.96	0.99	0.99
	Differencea	0.15***	0.15***	0.15***
	Correlationb	0.64***	0.55***	0.53***
	% youngerc better	2.0%	3.0%	0.6%
HAZ	N	272	309	131
	Children 6–59 m	1.17	1.24	1.27
	Children 6–23 m	1.21	1.28	1.29
	Children 24–59 m	1.13	1.20	1.24
	Differencea	0.09***	0.08***	0.06***
	Correlationb	0.68***	0.69***	0.64***
	% youngerc better	8.3%	11.5%	5.8%
MUACZ	N	264	307	131
	Children 6–59 m	0.95	0.97	0.97
	Children 6–23 m	1.00	1.02	1.04
	Children 24–59 m	0.90	0.92	0.92
	Differencea	0.10***	0.10***	0.12***
	Correlationb	0.62***	0.55***	0.57***
	% youngerc better	4.4%	4.8%	1.1%
BMIZ	N	272	309	131
	Children 6–59 m	1.05	1.09	1.12
	Children 6–23 m	1.10	1.14	1.18
	Children 24–59 m	1.01	1.05	1.06
	Differencea	0.09***	0.10***	0.12***
	Correlationb	0.68***	0.54***	0.61***
	% youngerc better	5.9%	8.0%	2.5%

WHZ Weight-for-height z-score, WAZ Weight-for-age z-score, HAZ Height-for-age z-score, MUACZ Mid-upper arm circumference-for-age z-score, BMIZ BMI-for-age z-score, SD Standard deviation, m months

P-values were calculated using parametric tests

*p < 0.05; **p < 0.01; ***p < 0.001

^aDifference between 6–23 and 24–59 months age groups

^b Correlation between 6–23 and 24–59 age groups

^c Percentage of surveys where absolute values for age group 6–23 months were lower that absolute values for age group 24–59 months