Table 3.

Predictors in Model 4

Predictors of 4-year-old FSIQ		Beta	Std. Error	Standardised Beta	t	sig	95% Conf. Interval
	(Constant)	24.870	10.163		2.447	0.016	4.695	45.043
At birth	Neonatal diagnosis of Bronchopulmonary dysplasia (BPD)	-8.458	3.560	-0.167	-2.376	0.019	-15.523	-1.392
	Higher level of maternal education	8.806	2.515	0.245	3.501	0.001	3.813	13.798
	Below average family wealth	-11.985	5.958	-0.145	-2.012	0.047	-23.811	-0.158
At 2 years of age	Developmental characteristics: mean performance based on the BSID-III cognitive, language and motor composite scores (∑Cog-Lang-Mot)	0.778	0.114	0.508	6.841	< 0.001	0.552	1.003

Coding of categorical data: Neonatal diagnosis of Bronchopulmonary dysplasia (BPD): Yes = 1, No = 0; Higher level of maternal education: Yes = 1, No = 0; Below average family wealth: Yes = 1, No = 0