Association of Age at Onset of Cigarette and Alcohol Use with Subsequent Smoking and Drinking Patterns among Japanese High School Students. (Research Papers)

Article excerpt

Cigarettes and alcohol are the substances most commonly used by Japanese adolescents, though minors are prohibited by law from smoking and drinking. In nationwide surveys of Japanese adolescents, the percentage of seventh graders who had ever tried smoking was 19% for males and 7% for females in 1990, and rates increased to 30% and 17%, respectively, in 1996. (1,2) In addition, 60% of junior high school students and 70% of senior high school students reported having drinking experiences in 1996. (3) Although the trend for prevalence of alcohol use remains unclear because of no periodic national survey, the drinking age among Japanese adolescents is becoming increasingly younger.

Health-risk behaviors including smoking and drinking increase the risk, chronicity, and intensity for adverse health and social outcomes as age increases, especially when risk behaviors begin at an early age. (4) For example, age of onset for smoking relates inversely to nicotine dependence, heavy smoking in both adolescence and adulthood, and smoking-attributable mortality. (5-8) Early initiation of alcohol drinking also influences later alcohol misuse and progression to alcohol dependence. (9,10)

Cigarettes and alcohol also represent gateway drugs, which precede use of other licit or illicit drugs. Several studies reported that cigarettes provided a gateway for adolescents to use other drugs, including alcohol. (11,12) Findings also indicate that alcohol represents a gateway drug for subsequent use of other drugs, including nicotine. (13) However, conclusions about gateway drugs from these studies remain controversial.

Studies in Japan attempted to determine the age at which adolescents initiate smoking and drinking. (1,2,14-17) However, researchers remain unsure whether early initiation of smoking or drinking influences subsequent behavior and subsequent substance use patterns. Knowledge about the impact of early initiation of smoking and drinking may improve understanding of gateway effects and the co-occurrence of cigarette and alcohol use among Japanese adolescents.

This study examined the relationship between age of onset for smoking and subsequent patterns of smoking and drinking among high school students in Japan. The study also examined the relationship between age of onset for drinking and subsequent patterns of smoking and drinking among Japanese students.


Procedures and Subjects

Using written instructions provided by researchers, classroom teachers conducted a self-administered, anonymous questionnaire survey in a classroom setting in September 1999. After being informed about the nature and intent of the study, both in writing and verbally, students were requested to complete and return a questionnaire sealed in a return envelope to assure confidentiality of the responses. Students could decline to respond to the questionnaire. No follow-up was conducted with students absent from school when the survey was conducted.

The study sample consisted of 1,466 students from one to two homeroom classes in grades 10 through 12 at seven public senior high schools in urban areas of Okinawa, Japan. Schools were chosen from four general high schools and three vocational high schools, based on willingness of school administrators to participate in the study. Questionnaires were collected from 1,317 students (644 males, 673 females). Twelve students declined to participate, and 137 were absent from school when the survey was conducted. A total of 1,290 students completed the smoking-status questions, while 1,308 students fully answered the alcohol use questions.

Measures and Data Analysis

Smoking and drinking status, and age of onset for these behaviors were measured using questions adapted mainly from the Youth Risk Behavior Surveillance conducted by the Centers for Disease Control and Prevention. (18) These questions were translated into Japanese and reviewed for content validity by school principals, teachers, school nurses, and researchers. …