Susceptibility Predicts Smoking Risk among Mexican-American Youth
M. D. Anderson News Release 12/03/09
Whether non-smoking Mexican-American adolescents go on to experiment with smoking depends largely on their initial attitude toward the habit, researchers at M. D. Anderson Cancer Center report in the December issue of Cancer Epidemiology, Biomarkers and Prevention, a journal of the American Association for Cancer Research.
Only 15 percent of those committed to never smoking at the start of a longitudinal study experimented with cigarettes over three years of follow-up. Over the same time, 45 percent of those who were deemed susceptible at first went on to experiment.
"Susceptibility to smoking is a measurable characteristic that predicts transition to smoking. Our results suggest that prevention efforts tailored to an adolescent's susceptibility status may be more effective among Mexican-American youth," said senior author Anna Wilkinson, Ph.D., assistant professor in M. D. Anderson's Department of Epidemiology.
Mexican-American adolescents are more inclined to experiment than other groups, and experimentation is likely to lead to a permanent habit, so understanding susceptibility offers an opportunity for early intervention, the authors note.
Susceptibility reflects the lack of a firm commitment to not smoke in the future assessed by a positive answer to at least one of three questions: whether they expect to try a cigarette soon, if they would smoke a cigarette offered by a friend, and whether they expect to be smoking in a year.
Wilkinson and colleagues followed 964 Mexican-origin girls and boys ages 11 to 13 from the Houston metro area who had never smoked for three years after initial assessment.
Without baseline susceptibility taken into account, the study identified significant predictors of experimentation, including being male, 13 years old, having low subjective social status, having some positive expectations about smoking, at least one school detention and living with someone who smokes.
When the researchers added the adolescents' baseline susceptibility status to the model, it became the strongest predictor of experimentation, causing a 2.6-fold increase in risk, and all other influences accept age and living with a smoker were no longer statistically significant.
While previous studies had demonstrated the importance of susceptibility among other ethnic groups, this study was the first to examine its role leading to experimentation among Mexican-American youth. The study's findings are consistent with those of other ethnic groups. "Our results suggest that being susceptible to smoking is not ethnic-specific," Wilkinson said.
Future studies need to focus on understanding and targeting risk factors for susceptibility to prevent experimentation and habitual smoking, the authors note.
Separate approaches need to be considered for those who are committed to never smoking, because 15 percent of them go on to experiment. Culturally sensitive approaches that rely more on peer influence might work well for this group, Wilkinson said.
The longitudinal study was made possible by the Mexican-American Cohort Study, an effort that has recruited more than 12,000 families to better understand factors that influence Mexican-American health over time. The cohort is funded by Texas Tobacco Settlement funds and M. D. Anderson.
This research was funded by a grant from the National Cancer Institute, the Duncan Family Institute for Cancer Prevention and Risk Assessment at M. D. Anderson and by the Caroline W. Law Fund for Cancer Prevention.
Co-authors with Wilkinson are first author Amy Spelman, Margaret Spitz, M.D., and Melissa Bondy, Ph.D., all of M. D. Anderson's Department of Epidemiology; Alexander Prokhorov, M.D., Ph.D., of M. D. Anderson's Department of Behavioral Science; Steven Kelder, Ph.D., of the Division Epidemiology at The University of Texas School of Public Health in Houston; and Ralph Frankowski, Ph.D., of the Division of Biostatistics, also at the UT School of Public Health. 12/03/09