Efficacy of genotype notification to Japanese smokers on smoking cessation—An intervention study at workplace

Objectives: It is well-known that smoking causes many diseases including cancers. Informing smokers of their genotypes associated with the vulnerability to the harms of smoking may be effective measures for smoking cessation. The present study examined the effects of genotype notification of an oncogene (L-myc) genotype to smokers on their behavior to quit smoking. Methods: Subjects were 562 employees of a bank who answered to be a smoker for a questionnaire used at annual health checkup at workplace from July to December 2002. Those enrolled on August, October, and December were allocated into the genotype notification group (intervention group), and the rest into the controls. Among 286 smokers allocated into the intervention group, 257 participants (89.9%) agreed to genotype testing. One year after the enrollment, a follow-up questionnaire survey was conducted for all smokers including controls. Results: Those who stated to have quitted smoking were 22 (8.0%) among the 276 controls and 15 (5.8%) among the 257 genotype notified participants, providing that the odds ratio (OR) of cessation for the intervention was 0.64 (95% confidence interval, 0.32–1.28). No psychological problems associated with genotype notification were observed. Conclusion: The present study did not show positive effects of genotype notification on smoking cessation rate. To elevate the cessation rate, methods to explain and notify genotypes should be improved.