Effectiveness and experience of implementing digital interventions to promote smoking cessation among adults with severe mental illness: A systematic review and meta-analysis.

Introduction: Digital technology is increasingly used to support interventions targeting smoking cessation in people with severe mental illness (SMI). However, little is known about their implementation and effectiveness in this population. We aimed to determine their effectiveness, stakeholder experiences, factors influencing implementation, and quality of reporting of digital interventions for smoking cessation in adults living with SMI.

Method: Five online bibliographic databases were searched for articles published between 31 December 2000 and 31 January 2023. Studies involving adults accessing treatment for alcohol and substance use disorders, neurocognitive disorders and terminal illnesses were excluded. Risk of bias was assessed using the Mixed Methods Appraisal Tool (MMAT). A Mantel-Haenszel random-effects meta-analysis of randomized controlled trials (RCTs) was conducted. Participant experience and intervention implementation were explored using a narrative synthesis. Quality of reporting of interventions was assessed using the Template for Intervention Description and Replication (TIDieR) checklist.

Results: Thirty-one studies enrolling 3,794 participants were included. Meta-analysis of biochemically verified abstinence at longest follow-up (month-1 to month-6) did not find an overall effect in favour of intervention [risk ratio (RR) = 0.66, 95% confidence interval (CI) = -0.005 - 1.37]. Interventions tailored to people with SMI were perceived as acceptable. Implementation strategies concentrated on overcoming practical challenges at the participant/user level.

Conclusion: No evidence of the effectiveness of digital interventions to support smoking cessation in people with SMI was found. The importance of tailoring interventions to the needs of people with SMI is highlighted. Robust reporting of implementation is required to enhance future efforts to support smoking cessation in adults with SMI.

Implications: The findings of this review add to the emerging evidence on digital interventions to support smoking cessation among people with SMI. We highlight the importance of tailoring interventions to the population, particularly considering the role of mental illness and the side effects of psychotropic medication in the accessibility and usability of digital interventions.