Risk factors for cigarette smoking among high school students in Okinawa, Japan.

: The purpose of this study was to examine the relationships between risk factors and smoking status among high school students in Okinawa, Japan. We also examined if there is a dose-response relation between the number of risk factors and smoking status. Self-reported questionnaires including smoking status and potential risk factors were conducted using a sample of 1,029 students of a public senior high school in Okinawa. The percentage of smokers was 40.0% for males and 10.6% for females, and it was significantly higher for males than females. As a result of multivariate analysis, we identified four significant risk factors; peer smoking, attitude of peer toward subject smoking, intention to smoke at the age 20, and alcohol drinking. The number of these risk factors was linearly associated with increased percentage of smokers, and a linear trend was significant for both gender students. Additionally, magnitude of risk for smoking among females became considerably great compared with those of males as the number of risk factors increased. In conclusion, this study was the first study in Japan to indicate a significant dose-response relationship between the number of risk factors and smoking status among high school students. We also found that females with many risk factors had extremely increased vulnerability to smoking compared to male counterpart. These findings may be useful to identify high-risk students who need more intensive smoking prevention programs and to develop the content of effective interventions.