Page 51 - Sample Moderate prematurity, socioeconomic status,
and neurodevelopment in early childhood
P. 51
Outcome, % (n/N) Total problems
Term-born
MP Externalizing
Term-born
MP Internalizing
Term-born MP
5.5 (4/73) 11.3 (21/186)
5.5 (4/73) 10.8 (20/186)
9.6 (7/73) 11.3 (21/186)
5.1 (18/355) 7.5 (43/573)
5.6 (20/355) 8.2 (47/573)
4.2 (15/355) 10.3 (59/573)
2.6 (3/115) 5.1 (8/156)
3.5 (4/115) 7.1 (11/156)
2.6 (3/115) 5.8 (9/156)
Effects of SES on behavioural and emotional problems
Table 2 Prevalence rates of clinically relevant CBCL scoresa in moderately preterm (MP) and term-born children according to socioeconomic status (SES)
CBCL Outcome
Low SESb
Intermediate SES
High SES
a Clinically relevant Child Behavior Checklist (CBCL) scores: scores higher than the cut-off at the 90th percentile.
b Low SES, 1 SD or more below the mean of the standardised SES; intermediate SES, scores between mean - 1 SD and mean + 1 SD; high SES, scores + 1 SD or more above the mean.
Table 3 shows the ORs and 95% CIs for clinically relevant CBCL scores per SD
decrease in SES and MP birth (per SD gestational age). We used standardised values 4 for SES and MP birth, with lower values indicating higher risk. The univariate ORs
were hardly affected by mutual adjustment for SES and MP birth (Model 1). In
Model 2 we added the SES * MP birth interaction in order to assess joint effects
of the risk factors. No statistically significant effects were found, which meant that
effects of SES and MP birth were multiplicative (as is the case for any logistic model
without interactions). Finally, in Model 3 we adjusted the ORs of Model 1 for gender,
number of siblings, and maternal age. This hardly affected the point estimates.
Table 3 Odds ratios (95% confidence intervals) for behavioural and emotional problems: effects of socioeconomic status (SES) and moderately preterm (MP) birth in three multivariate logistic regression models
CBCL Outcome
Univariate
Model 1
Model 2
Model 3
Score, OR (95% CI)a Total problems
SES
MP birth SES*MP birth
Externalizing SES
MP birth
SES*MP birth Internalizing
SES
MP birth SES*MP birth
1.38 (1.12 - 1.70)*** 1.29 (1.03 - 1.61)*
1.20 (0.98 - 1.46) 1.33 (1.07 - 1.64)**
1.28 (1.06 - 1.55)* 1.43 (1.16 - 1.77)***
1.36 (1.10 - 1.68)*** 1.26 (1.01 - 1.57)*
1.17 (0.96 - 1.43) 1.31 (1.06 - 1.62)*
1.25 (1.03 - 1.52)* 1.40 (1.14 - 1.74)***
1.48 (1.15 - 1.92)*** 1.40 (1.04 - 1.88)* 0.83 (0.60 - 1.15)
1.23 (0.95 - 1.59) 1.37 (1.04 - 1.80)* 0.92 (0.66 - 1.27)
1.45 (1.14 - 1.85)*** 1.64 (1.25 - 2.16)*** 0.76 (0.56 - 1.02)
1.42 (1.14 - 1.77)*** 1.24 (1.00 - 1.56)
1.21 (0.99 - 1.50) 1.31 (1.05 - 1.63)*
1.26 (1.03 - 1.54)* 1.41 (1.13 - 1.73)***
Levels of significance: * indicates p < .05, ** indicates p < .01, and *** indicates p < .005
Model 1: assessing the effects of socioeconomic status (SES) and moderately preterm (MP) birth in a multivariate model.
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