Effectiveness of tobacco cessation interventions delivered in clinical settings in South Asia: a systematic review and meta-analysis.
BACKGROUND: Despite the burden of tobacco use, access to cessation support in South Asia remains scarce. OBJECTIVE: This review evaluates the effectiveness of tobacco cessation interventions delivered in clinical settings in South Asia. METHODS: Five relevant databases were searched from inception to February 2025. Eligibility criteria included randomized and non-randomized studies evaluating behavioral, pharmacotherapy, and multicomponent interventions delivered in clinical settings in South Asia. Data on study setting and design, participant information, intervention, comparator, and outcomes were extracted. Meta-analyses using random-effect models were conducted where possible. Certainty of evidence was assessed using GRADE. RESULTS: Thirty-seven studies were included (22 randomized and 15 non-randomized). Interventions involved pharmacotherapy (n = 6; 16.2%), nicotine replacement therapy (n = 7; 18.9%), behavioral counseling (n = 12; 32.4%), or combined/multicomponent interventions (n = 12; 32.4%). Most studies were conducted in India (n = 26; 70.3%), followed by Pakistan (n = 6; 16.2%), Nepal (n = 3; 8.1%), and two studies (5.4%) were multi-country in India, Pakistan, and Bangladesh. Pooled analyses demonstrated higher quit rates among intervention versus control for continuous abstinence at 0-3 months (RR: 1.21, 95%CI: 1.06 to 1.37) and >3 months (RR: 1.68, 95%CI: 1.1.4 to 2.47), and for point abstinence at >3 months post-intervention (RR: 2.03, 95%CI:1.35 to 3.08). Heterogeneity was high for all analyses (I2 range: 94% to 97%). Combined behavioral and pharmacotherapy interventions were most effective (RR: 1.70, 95%CI: 0.98 to 2.92), although not statistically significant (p = 0.06). CONCLUSION: Tobacco cessation interventions delivered in clinical settings in South Asia are effective, particularly when combining behavioral support with pharmacotherapy. However, evidence is limited by methodological weaknesses.