Table 2.
Risk difference (RD) and relative risk (RR) from interaction models for the association between developmental vulnerability on the Australian Early Developmental Census (AEDC) and preterm birth status.
| Preterm Birth Status | Developmentally Vulnerable on one or more AEDC Domains | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| n (%)a | Model 0b | Model 1c | Model 2d | Model 3e | |||||
| RD % (95% CI)f | RR [95% CI]g | RD % (95% CI) | RR [95% CI] | RD % (95% CI) | RR [95% CI] | RD % (95% CI) | RR [95% CI] | ||
|
Extremely preterm (< 28 weeks) |
49 (37.1) | 15.32 (7.07–23.57) | 1.70 [1.36–2.13] | 17.98 (9.44–26.52) | 1.78 [1.41–2.25] | 12.74 (4.66–20.81) | 1.54 [1.23–1.92] | 12.35 (4.64–20.05) | 1.55 [1.25–1.93] |
|
Very preterm (28–31 weeks) |
115 (39.1) | 17.31 (11.73–22.9) | 1.79 [1.55–2.07] | 16.05 (10.56–21.53) | 1.75 [1.52–2.01] | 11.21 (5.93–16.49) | 1.46 [1.28–1.68] | 9.12 (4.12–14.12) | 1.34 [1.18–1.53] |
|
Moderate/late preterm (32–36 weeks) |
1084 (29.2) | 7.42 (5.92–8.92) | 1.34 [1.27–1.41] | 6.78 (5.32–8.23) | 1.32 [1.25–1.39] | 4.56 (3.19–5.93) | 1.20 [1.14–1.26] | 3.23 (1.95–4.52) | 1.14 [1.09–1.19] |
|
Term (≥ 37 weeks) |
13,228 (21.8) | 0 (ref) | 1 [ref] | 0 (ref) | 1 [ref] | 0 (ref) | 1 [ref] | 0 (ref) | 1 [ref] |
| Developmentally vulnerable on two or more AEDC Domains | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| n (%)a | Model 0b | Model 1c | Model 2d | Model 3e | |||||
| RD (95% CI)f% | RR [95% CI]g | RD (95% CI) | RR [95% CI] | RD (95% CI) | RR [95% CI] | RD (95% CI) | RR [95% CI] | ||
|
Extremely preterm (< 28 weeks) |
26 (19.7) | 8.97 (2.18–15.76) | 1.84 [1.30–2.59] | 10.64 (3.64–17.65) | 1.95 [1.37–2.78] | 6.72 (0.42–13.01) | 1.61 [1.15–2.26] | 6.59 (0.68–12.49) | 1.67 [1.20–2.33] |
|
Very preterm (28–31 weeks) |
67 (22.8) | 12.06 (7.26–16.86) | 2.12 [1.72–2.63] | 10.81 (6.25–15.37) | 2.05 [1.67–2.52] | 7.81 (3.30–12.33) | 1.64 [1.34–2.00] | 6.60 (2.35–10.86) | 1.48 [1.21–1.80] |
|
Moderate/late preterm (32–36 weeks) |
583 (15.7) | 4.99 (3.79–6.19) | 1.47 [1.36–1.58] | 4.47 (3.34–5.61) | 1.44 [1.33–1.55] | 3.03 (1.94–4.12) | 1.25 [1.16–1.35] | 2.03 (1.02–3.03) | 1.17 [1.09–1.26] |
|
Term (≥ 37 weeks) |
6509 (10.7) | 0 (ref) | 1 [ref] | 0 (ref) | 1 [ref] | 0 (ref) | 1 [ref] | 0 (ref) | 1 [ref] |
Developmental vulnerability was defined as scores in the bottom decile, based on the 2009 AEDC cut-offs. Adjusted models based on pooled analysis from 20 imputed datasets; modified Poisson Regression (n = 64,810 children).
aNumber of children classified as developmentally vulnerable.
bModel 0 was unadjusted.
cModel 1 was adjusted for sex of child and age of child at time of AEDC completion.
dModel 2 was adjusted for all variables as per Model 1 and for sociodemographic and maternal confounders (maternal age at time of child’s birth, maternal marital status at time of child’s birth, maternal immigration status, ethnicity of mother, maternal occupational status at time of child’s birth, parity, child speaks a language other than English at home, total number of siblings, and Index of Relative Socioeconomic Disadvantage category).
eModel 3 was adjusted for all variables as per Model 2 and controlled for modifiable variables (preschool attendance and child’s reading status at home).
fData presented as Risk Difference (95% Confidence Intervals).
gData presented as Relative Risk [95% Confidence Intervals].