Table 3.

Smoking at all versus no smoking across predictors at baseline (1990) and final wave (1995)

		Own smoking behaviour 1990				Own smoking behaviour 1995
		Yes	No	n	Differencea	Yes	No	n	Differencea
Gender	Boy	12%	88%	887	χ2 = .04, df = 1, p > 0.05	45%	55%	776	χ2 = 2.58, df = 1, p > 0.05
	Girl	12%	88%			51%	49%
Father smoking	Yes	15%	85%	858	χ2 = 5.74, df = 1, p < 0.01	59%	41%	617	χ2 = 24.91, df = 1, p < 0.05
	No	9%	91%			39%	61%
Mother smoking	Yes	15%	85%	874	χ2 = 7.86, df = 1, p < 0.01	58%	42%	631	χ2 = 16.75, df = 1, p < 0.05
	No	9%	91%			41%	59%
Older sibling smoking	Yes	27%	73%	846	χ2 = 51.43, df = 1, p < 0.001	66%	34%	610	χ2 = 18.93, df = 1, p < 0.00
	No	7%	93%			44%	56%
Best friend smoking	Yes	67%	33%	874	χ2 = 305.36, df = 1, p < 0.00	78%	22%	631	χ2 = 25.59, df = 1, p < 0.00
	No	5%	95%			45%	55%
Allowed smoking	Yes	33%	67%	764	NAb	33%	67%	556	NAb
	No	11%	89%			47%	53%
Parents' SES	Low	12%	88%	431	χ2 = 5.93, df = 2, p < 0.05	49%	51%	351	χ2 = 1.05, df = 2, p > 0.05
	Mid	11%	89%			46%	54%
	High	4%	96%			52%	48%

^aChi-square test of difference

^bNot estimable because expected frequency was lower than 5