Table 3.

Differential effects of parental smoking according to offspring sex, age, and the presence of the father in the household

	Odds Ratio	95% CI	Odds Ratio	95% CI
	Differential effects according to offspring sex
	Girlsa		Boysa
Mother's Smoking	2.73	1.50,4.98	2.29	1.39,3.77
Father's Smoking	1.06	0.59, 1.89	2.39	1.45,3.92
	Differential effects according to offspring age
	≤Age 12b		≥Age 13b
Mother's or Father's Smoking	3.63	2.07, 6.36	1.71	1.06,2.76
	Differential effects according to father's presence in the household
	Father at homec		Father not at homec
Father's Smoking	3.18	1.93,5.23	1.13	0.59,2.17

^aResults of two discrete-time survival models of the age at smoking initiation, one estimated for girls and one for boys. Models also adjusted for age at interview and the baseline hazard of initiation in each year of life.

^bResults of two discrete-time survival models of the age at smoking initiation, one estimate for person-years through age 12, and one for person-years 13 and above. Models also adjusted for adolescent sex, age at interview, and the baseline hazard of initiation in each year of life.

^cResults of two discrete-time survival models of the age at smoking initiation, one estimate for person-years in which the father was living at home, and one for person-years when father was not living at home. Models also adjusted for adolescent sex, age at interview, and the baseline hazard of initiation in each year of life.