Tobacco smoking among people living with HIV receiving care at outpatient clinics in Hanoi, Vietnam.

Abstract

Background: Tobacco use remains disproportionately high among people living with HIV (PLWH), yet the factors driving continued smoking and barriers to cessation in this population remain underexplored, particularly in low- and middle-income countries (LMICs), including Vietnam. Methods: This thesis unfolds through four interconnected studies, beginning with a global systematic review and meta-analysis of 80 studies mapping the factors influencing smoking behaviors and cessation among PLWH worldwide. Shifting the focus locally, the second study uses qualitative interviews with PLWH receiving clinical care and their healthcare providers to capture nuanced perspectives on the barriers and facilitators to quitting. Building on these insights, the final two studies employ multiple logistic regression to examine smoking behaviors among 672 PLWH receiving HIV care at clinics and enrolled in a tobacco treatment program in Hanoi, Vietnam. The third study explores the correlates of dual tobacco use–cigarettes and waterpipes–while the fourth investigates how smokers’ perceptions of smoking-related risks, perceived social norms and self-efficacy are associated with their intentions to quit cigarette smoking. Results: The systematic review revealed a substantial research gap on tobacco use among PLWH in LMICs. The meta-analysis identified male gender, substance use, and depression as significant correlates of both current smoking and unsuccessful cessation, while older age and previous quit attempts were associated with abstinence. Nicotine dependence was also linked to non-abstinence. In Hanoi, Vietnam, the qualitative study identified multiple barriers to quitting tobacco across individual (e.g., low perceived risk of smoking, psychological distress, nicotine dependence, strong pro-smoking norms and networks), provider (e.g., limited skills and knowledge, competing clinical demands), and system levels (e.g., inadequate tobacco control efforts). Key facilitators included patient–provider trust, family support, and personal willpower. In subsequent analyses, the third study found that more than half of the participants reported dual smoking, which was associated with low income, drug use, high nicotine dependence, longer duration on antiretroviral treatment, and the belief that cigarettes are more harmful than waterpipes; past quit attempts and social support were associated with lower odds of dual smoking. The final study found that higher smoking-related risk perception, greater perceived injunctive, subjective and internalized/moral norms were associated with a high intention to quit. Conclusions: This thesis shows that tobacco use among PLWH receiving treatment at HIV clinics in Hanoi, Vietnam, is shaped by interrelated social norms, psychological factors, individual health behaviors, and structural conditions within HIV care. Higher quit intention was most strongly associated with higher smoking-related risk perception and the presence of injunctive, subjective, and internalized anti-smoking norms. These findings suggest that effective cessation strategies should combine clear and contextually tailored risk communication with psychosocial support, address comorbid conditions such as substance use and depression, and actively leverage social support networks. Embedding evidence-based tobacco treatment within routine HIV care and addressing both individual- and system-level barriers will be critical to reducing tobacco use among PLWH.