Table 4.
Prevalence and RRs for verbal cognitive development, by BMF initiation and duration
| Verbal cognitive development | |||||
|---|---|---|---|---|---|
| Optimal | Suboptimal | Crude RRb | Adjusted RRb (95% CI) | ||
| n (%)a | n (%)a | (95% CI) | Model 1 | Model 2 | |
| BMF initiation | (n = 4118) | (n = 3999) | (n = 3625) | ||
| Never breastfed | 753 (84.3) | 134 (15.7) | 1.73 (1.19‐2.52) | 1.59 (1.16‐2.19) | 1.45 (1.09‐1.92) |
| Ever breastfed | 2926 (90.4) | 305 (9.6) | Reference | Reference | Reference |
| BMF duration | (n = 3894) | (n = 3787) | (n = 3440) | ||
| Never breastfed | 753 (84.3) | 134 (15.7) | 1.78 (1.23–2.59) | 1.65 (1.19–2.31) | 1.50 (1.12–2.00) |
| >0 to <2 Months | 416 (89.4) | 47 (10.6) | 1.18 (0.77–1.79) | 1.42 (1.00–2.03) | 1.21 (0.93–1.59) |
| 2 to <4 Months | 798 (91.3) | 77 (8.7) | 0.93 (0.78–1.10) | 0.92 (0.76–1.13) | 0.97 (0.74–1.26) |
| 4 to <6 Months | 516 (92.8) | 43 (7.2) | 0.80 (0.50–1.27) | 0.72 (0.46–1.12) | 0.80 (0.49–1.31) |
| ≥6 Months | 1010 (90.8) | 100 (9.2) | Reference | Reference | Reference |
| p | 0.017 | 0.005 | 0.011 | ||
Note: Model 1: Adjusted for child sex, CA at assessment and perinatal risk. Model 2: Adjusted for child sex, CA at assessment, perinatal risk, maternal age, parity, type of pregnancy, mother's country of birth, mother's educational level and family situation.
Abbreviations: BMF, Breast milk feeding (mother's own milk); CA, corrected age; CI, confidence interval; RR, Risk ratio.
Proportions were calculated using inverse probability weights to account for nonresponse bias.
RRs were derived from the weighted sample (inverse probability of participating at the 2 years CA follow‐up), multilevel mixed‐effects generalized linear regression models with random intercepts at the country and mother level.