Table 2.

Cotinine measurements in 374 people^* with information on exposure to environmental tobacco smoke

	Cotinine
ETS status	Mean (SD)†	Detectable (>0.05 ng/ml)	Undetectable
Yes (n=189)	0.55 (0.96)	89	100
No (n=174)	0.17 (0.49)	37	137

^*Eleven people with cotinine concentration >10 ng/ml excluded.

^†P<0.0001 for difference (Wilcoxon Rank sum test).