Depressive symptoms are associated with cigarette smoking among tuberculosis patients in Botswana

Background: Researchers have increasingly recognized the adverse effects of smoking on tuberculosis (TB) outcomes. Smoking may be a maladaptive coping mechanism for depression and anxiety among TB patients; however, this association has not yet been investigated. Design/Methods: We conducted a cross-sectional study among newly diagnosed TB patients between January and December 2019 in Gaborone, Botswana, and evaluated factors associated with cigarette smoking. Using the Patient Health Questionnaire-9 and the Zung Self-Rating Anxiety scale, we collected depression and anxiety scores, respectively; scores of ≥10 indicate depression and scores of ≥36 indicate anxiety. We performed Poisson regression analyses with robust variance to examine whether depression and anxiety were associated with smoking. Results: One hundred and eighty participants with TB were enrolled from primary health clinics. Among all enrollees, depression was reported in 46 (27.1%) participants, while anxiety was reported in 60 (44.4%) participants. Overall, 45 (25.0%) participants reported current smoking, and the median number of cigarettes per day was 10. Depressive symptoms were associated with a higher prevalence of smoking (aPR: 1.82; 95% CI = 1.11, 3.01) after adjusting for sex, HIV status, food insecurity, anxiety, and income. The association between anxiety symptoms and cigarette smoking did not reach statistical significance (aPR 1.26; 95% CI: 0.78-2.05). Conclusions: We found the association between depressive symptoms and smoking among TB patients in Botswana to be significant and the association between anxiety symptoms and cigarette smoking insignificant. Future studies should further investigate these associations when addressing TB care.