Table 1.

Estimated odds ratios, 95% confidence intervals (CI) and t statistic for the effects of age at introduction to formula or solids, the interaction effects between this variable and age at breastfeeding cessation, and timing of follow-up waves on odds of overweight or obesity.

Covariate	Odds Ratio	95% CI	t Ratio
Model 1 Age at starting formula or solids ≤4 months vs. >4 months	2.3262	1.8025–2.4132	2.3026 a
Model 2 Age at starting formula or solids ≤4 months vs. >4 months	1.9543	1.1010–3.4687	2.27 a
Model 3 Age at starting formula or solids * age at breastfeeding cessation ≤4 months * ≤4months vs. >4months * >4 months	2.0856	1.1225–4.8205	1.9845 a
Model 4 Time*Age at starting formula or solids
Age 2/3 * ≤4 months	0.3569	0.0668–1.9058	−1.21
Age 4/5 * ≤4 months	0.8437	0.1547–4.6014	−0.20
Age 6/7 * ≤4 months	0.9050	0.1564–5.2385	−0.11
Age 8/9 * ≤4 months	0.4573	0.0810–2.5828	−0.89
Age 10/11 * ≤4 months vs. Age 0/1 * >4 months	0.6093	0.1001–3.7088	−0.54

Notes: * indicates product sign. All models controlled for the effect of time while models 2–4 also controlled for children’s age at breastfeeding cessation, maternal age, body mass index (BMI) during pregnancy, and social advantage index; the statistical tests are performed at 5% level of significance; the superscript ^a indicates p < 0.05.