Table 2.

Mean age (standard deviations) at puberty events by early tobacco and alcohol use.

	Breast Development		Body Hair Growth		Menarche
	n	Mean (sd)	n	Mean (sd)	n	Mean (sd)
Early Alcohol Use
No	2835	11.0 (1.25)	2756	11.1 (1.16)	2119	11.7 (1.29)
Yes	59	11.9 (2.25)	60	11.5 (1.38)	75	12.5 (1.65)
p-value†		<0.001		0.07		<0.001
Early Tobacco Use
No	2832	11.0 (1.28)	2758	11.1 (1.16)	2107	11.7 (1.29)
Yes	62	11.9 (1.32)	58	11.8 (1.15)	87	12.5 (1.52)
p-value†		<0.001		<0.001		<0.001

^†Differences in mean age at pubertal event were assessed using t-tests with standard errors corrected using heteroskedasticity-consistent covariance matrix estimator that does not assume independent cases within clusters (families).