Prevalence of smoking and oral contraception in a sample of Danish young women.

A representative sample of 286 Danish females aged 16-20 years were interviewed during the period April 1984--February 1985. The response rate was 75%. Both use of oral contraception (OC) and smoking were common; 46.6% used OC, 34.2% smoked and 19.6% combined smoking and OC. The prevalence of smoking was significantly higher (42.0%) among OC-users than among non-users (27.2%). The combination of smoking and OC was especially prevalent among young women with sexual debut before 16 years (36.8%). The association between smoking and the use of OC was significant both when tested unstratified (p less than 0.05) and stratified by age at sexual debut (p less than 0.01). Smoking was also associated with early debut of intercourse (p less than 0.001). It has been reported that the combination of these two factors in adult women increase the risk for cardiovascular mortality. However, the health consequences later in life of combining smoking and OC at young ages have not been illuminated in the literature. These findings indicate the necessity for prospective studies of young women.