The association between smoking and sexual behavior among teens in US contraceptive clinics.

A study of teenage women in 32 contraceptive clinics in the United States shows a strong negative relationship between age of first intercourse and the level of cigarette smoking; the association is strong enough to reverse the usual correlation of smoking and age during the teenage years. Preventive, timely contraceptive behavior is also negatively associated to smoking. These findings suggest that interventions could well be designed and located in settings which take this association into account.