Smoking cessation interventions for hospitalised individuals with severe mental illness: a systematic review and meta-analysis

Objective People with severe mental illness (SMI) have higher smoking rates, smoke more heavily and benefit less from general tobacco control strategies. Hospitalisation offers an opportunity to initiate smoking cessation interventions. This review aimed to evaluate the effectiveness of hospital-initiated interventions on quit rates among people with SMI. Data sources Six international databases and four Chinese databases were systematically searched from their inception up to 21 March 2025. Study selection Randomised controlled trials (RCTs) were included if they evaluated hospital-initiated smoking cessation interventions among individuals with SMI. Data extraction Two reviewers independently extracted the data and resolved any discrepancies through discussion, involving a third reviewer when necessary. Data synthesis 10 RCTs were included in this review. Meta-analysis found that hospital-initiated smoking cessation interventions significantly increased quit rates at short-term (risk ratio (RR)=2.98, 95% CI 1.15 to 7.73) and medium-term (RR=1.93, 95% CI 1.21 to 3.07) follow-ups. The long-term effect favoured the intervention group but was not statistically significant (RR=1.61, 95% CI 0.93 to 2.78). The interventions also significantly reduced short-term daily cigarette consumption (mean differences=−5.98 cigarettes per day, 95% CI −8.29 to −3.67) and improved anxiety (standardised mean differences (SMD)=−1.83, 95% CI −2.55 to −1.11) and depressive symptoms (SMD=−1.18, 95% CI −2.19 to −0.16). Conclusions Hospitalisation provides a critical window to initiate smoking cessation interventions among patients with SMI. Such interventions improved smoking abstinence and mental health outcomes while reducing cigarette consumption. Intervention duration may be important for sustaining abstinence over time.