Table 2

Linear regression of Bayley motor and cognitive scores by WHO growth parameters

	HC z-score			Length z-score			Weight z-score			Overall	BMI z-score
	Estimate	SE	p Value	Estimate	SE	p Value	Estimate	SE	p Value	p Value	Estimate	SE	p Value
9-month Bayley score by 9-month anthropometry
Motor	0.60	0.19	0.002	0.97	0.25	0.0001	0.75	0.25	0.003	0.005	0.18	0.22	0.4
Cognitive	0.39	0.23	0.09	1.24	0.30	<0.0001	1.23	0.29	<0.0001	0.004	0.48	0.25	0.06
2 years Bayley score by 9-months anthropometry
Motor	0.23	0.22	0.3	0.83	0.29	0.004	1.0	0.28	0.0003	0.02	0.45	0.24	0.06
Cognitive	0.41	0.18	0.02	0.64	0.23	0.005	0.57	0.22	0.01	0.01	0.13	0.19	0.5
2-year Bayley score by 2-year anthropometry
Motor	1.17	0.33	0.0004	1.51	0.35	<0.0001	1.57	0.32	<0.0001	<0.0001	0.95	0.32	0.004
Cognitive	0.57	0.27	0.03	1.09	0.28	0.0001	0.64	0.26	0.01	0.0006	0.36	0.27	0.2
Change in Bayley by 9-month anthropometry*
Motor	0.0051	0.21	1.0	0.57	0.28	0.04	0.64	0.27	0.02	0.18	0.31	0.28	0.3
Cognitive	0.23	0.17	0.2	0.56	0.23	0.02	0.24	0.22	0.03	0.19	−0.45	0.28	0.1

Relationships shown are for z-scores of each of the anthropometric measures, corrected for gestational age at 9 months but not 2 years. All models adjusted for sex, race/ethnicity, SES and birthweight. Bold face indicates p<0.05.
*Analysis regarding change in Bayley further adjusted for 9-month Bayley scores.
†Overall p value represents the significance of the combined effects of HAZ, WAZ and HCZ on the Bayley score, adjusting for sex, race/ethnicity, SES and birthweight, and in the final two models, 9 month Bayley score.
BMI, body mass index; HC, head circumference; SES, socio-economic status.