Table 3.

Comparison of regression models. The best fitting model (i.e. that with the lowest AIC) was the interaction model (Model 3) and was therefore set to be the reference model (in bold). The relative fit of other models was compared to this best model by comparing differences between the AIC for each model. The next best fitting model was that with puberty alone, and finally the lowest ranking model was that with age alone. R² values are included for each model. Unstandardised (B) and standardised (β) coefficients, as well as the standard error of the unstandardised coefficient (SE B) are shown for each variable.

Variable	Model 1			Model 2			Model 3
	Puberty only			Age only			Interaction
	B	SE B	β	B	SE B	β	B	SE B	β
Puberty	−0.025	0.006	−0.48***				−0.260	0.007	−0.48***
Age				−0.110	0.004	−0.36**	0.007	0.007	0.24
Puberty × age							−0.018	0.008	−0.50*
R2	0.227			0.132			0.332
AIC difference	3.76			11.2			0 (reference)

^*p < 0.05.

^**p < 0.005.

^***p < 0.001.