Examining the Moderating Role of the Intensity of Cigarette Smoking in the Relationship Between Job Demands and Burnout: A Cross-Sectional Study Among Japanese Workers

Objective A growing body of studies has shown that cigarette smoking is related to high levels of burnout. However, little is known about the role of smoking in the relationship between job demands and burnout. This study aims to address this gap by examining the moderating effect of smoking intensity (i.e., the average number of cigarettes smoked per day) on the relationship between job demands and burnout in Japanese workers. Methods A cross-sectional survey including questions about demographics, smoking status, job demands, and burnout was conducted among Japanese workers. Smoking intensity was measured using a single item referring to the average number of cigarettes smoked per day. Job demands were assessed using the New Brief Job Stress Questionnaire (for quantitative job overload) and the Quality of Work Index and Quality of Employment Index (for cognitive demands and emotional demands). Burnout was assessed using the 12-item version of the Burnout Assessment Tool. The data of 302 current smokers (70.2% male participants) were analyzed using a hierarchical multiple regression model. In Step 1, demographic factors such as age, sex, and employment status were entered. In Step 2 and Step 3, job demands and smoking intensity were added, respectively. Finally, in Step 4, the interaction term of job demands and smoking intensity was added to test whether smoking intensity conditions the job demands-burnout relationship. Results The result showed that the main effect of job demands on burnout was significant (Step 2: β=0.520, p<0.001), after controlling for the effect of demographic factors. This model accounted for 26.8% of the variance in burnout. In turn, the main effect of smoking intensity on burnout was also significant (Step 3: β=0.112, p=0.026). The inclusion of smoking intensity in the model resulted in accounting for an additional 1.2% of the variance in burnout. Furthermore, the effect of the interaction term of smoking intensity and job demands was also significant (Step 4: β=0.116, p=0.018). The final model accounted for an additional 1.3% of the variance in burnout. A post-hoc test revealed that the positive association between job demands and burnout was stronger for more intensive smokers (β=0.617, p<0.001, 95% CIs (0.486, 0.748)) than for less intensive smokers (β=0.406, p<0.001, 95% CIs (0.280, 0.532)). Conclusion The present results suggest that heavy smoking may undermine individuals' ability to effectively manage job demands, thereby increasing their susceptibility to burnout. Thus, although smoking offers temporary stress relief, heavy reliance on it may have a negative impact on occupational well-being. Accordingly, interventions aimed at reducing the burnout risks among smokers may benefit from incorporating smoking-reduction or cessation strategies, alongside stress management tactics.