Effects of different interventions on smoking cessation in patients with chronic respiratory diseases: a systematic review and network meta-analysis

Background Chronic respiratory diseases (CRDs) impose a substantial global burden, and smoking cessation is the single most effective intervention to slow disease progression and reduce mortality. To date, no network meta-analysis has examined whether combining COPD and non-COPD CRDs alters effect estimates compared with a COPD-only analysis. Methods PubMed, Embase, Web of Science, Cochrane Library, CINAHL, and PsycINFO were searched from inception to June 3, 2026, for English-language randomized controlled trials (RCTs) of any cessation intervention in smokers with confirmed CRDs. The primary outcome was smoking cessation at a comparable follow-up window (trials with follow-up ≥6 months); the analysis based on the final follow-up of all trials was retained as a sensitivity analysis. We performed a frequentist random-effects network meta-analysis, assessed risk of bias using RoB 2.0, and evaluated evidence certainty with CINeMA. Results Twenty-four RCTs (26 publications) involving 14 interventions were included. Compared with usual care, cognitive behavioral therapy (CBT; OR = 5.54, 95% CI: [2.07, 14.86]), CBT plus nicotine replacement therapy (CBT + NRT; OR = 5.43, 95% CI: [1.61, 18.35]), and combined interventions (OR = 3.09, 95% CI: [1.02, 9.34]) were associated with significantly higher cessation rates in the primary (follow-up ≥6 months) analysis. Cytisine versus usual care showed a high point estimate but did not reach statistical significance, as it was supported by a single trial (OR = 4.33, 95% CI: [0.26, 72.27]). CBT and CBT + NRT showed the most consistent signals across time points, particularly for long-term abstinence (>6 months). In the multivariable meta-regression, lower national income was associated with larger effects ( β = −0.32, p = 0.018), but this association should be regarded as exploratory because it is ecological. The certainty of evidence was low to very low for all comparisons. Conclusion CBT alone and CBT + NRT both show promising signals for smoking cessation in patients with CRDs. However, the evidence is of low to very low certainty, so these findings should be considered preliminary. Future large, high-quality randomized controlled trials are needed to confirm these findings. Systematic review registration https://www.crd.york.ac.uk/PROSPERO/view/CRD420261429820 . Identifier PROSPERO, CRD420261429820.