Table 1.

HPRT M_f in newborns with and without exposure to tobacco smoke metabolites in utero

		HPRT Mf (× 10-6)
maternal exposure	N	mean ± SD	median	range	P1,2	P2,3
a) data from Manchester et al [21]
unexposed	18	0.76 ± 0.50	0.61	0.14 – 1.9
passive only	20	1.60 ± 1.43	1.35	0.30 – 5.3	0.021
quit during pregnancy4	4	1.85 ± 1.16	1.60	0.35 – 3.2	0.004
smoked throughout	27	1.36 ± 0.99	0.98	0.28 – 3.5	0.019	0.012
b) data from Finette et al [22,23]
unexposed	26	0.72 ± 0.53	0.52	0.05 – 1.9
passive only5	22	1.18 ± 1.28	0.67	0.10 – 5.1	0.14
quit during pregnancy	8	0.79 ± 0.46	0.69	0.18 – 1.8	0.51
smoked throughout	12	0.71 ± 0.51	0.56	0.14 – 1.8	0.73	0.47
c) pooled data
unexposed	44	0.73 ± 0.51	0.60	0.05 – 1.9
passive only5	42	1.38 ± 1.36	0.87	0.10 – 5.3	0.006
quit during pregnancy4	12	1.27 ± 0.93	0.91	0.18 – 3.2	0.014
smoked throughout	39	1.16 ± 0.91	0.87	0.14 – 3.5	0.007	0.007

¹specific exposed group vs. unexposed HPRT M_f from single factor ANOVA on ln transformed data

²since these four tests were performed simultaneously, to preserve an overall α of 0.05, the threshold for significance of each individual test should be set at P = 0.0125, or, if exposure is only tested for an induction of mutation, P = 0.025

³overall single factor ANOVA on ln transformed data

⁴excluding outlier with HPRT M_f of 14.7 × 10^-6

⁵excluding outlier with HPRT M_f of 45.3 × 10^-6