Identifying misclassification in youth self-reported smoking status: testing different consent processes of biological sample collection to capture misclassification

A Scoping Review and Meta-analysis of the Use of Remote Biochemical Verification Methods of Smoking Status in Tobacco Research

INTRODUCTION

Increasing digital delivery of smoking cessation interventions has resulted in the need to employ novel strategies for remote biochemical verification.

AIMS AND METHODS

This scoping review and meta-analysis aimed to investigate best practices for remote biochemical verification of smoking status. The scientific literature was searched for studies that reported remotely obtained (not in-person) biochemical confirmation of smoking status (ie, combustible tobacco). A meta-analysis of proportions was conducted to investigate key outcomes, which included rates of returned biological samples and the ratio of biochemically verified to self-reported abstinence rates.

RESULTS

A total of 82 studies were included. The most common samples were expired air (46%) and saliva (40% of studies), the most common biomarkers were carbon monoxide (48%) and cotinine (44%), and the most common verification methods were video confirmation (37%) and mail-in samples for lab analysis (26%). Mean sample return rates determined by random-effects meta-analysis were 70% for smoking cessation intervention studies without contingency management (CM), 77% for CM studies, and 65% for other studies (eg, feasibility and secondary analyses). Among smoking cessation intervention studies without CM, self-reported abstinence rates were 21%, biochemically verified abstinence rates were 10%, and 47% of individuals who self-reported abstinence were also biochemically confirmed as abstinent.

CONCLUSIONS

This scoping review suggests that improvements in sample return rates in remote biochemical verification studies of smoking status are needed. Recommendations for reporting standards are provided that may enhance confidence in the validity of reported abstinence rates in remote studies.

IMPLICATIONS

This scoping review and meta-analysis included studies using remote biochemical verification to determine smoking status. Challenges exist regarding implementation and ensuring high sample return rates. Higher self-reported compared to biochemically verified abstinence rates suggest the possibility that participants in remote studies may be misreporting abstinence or not returning samples for other reasons (eg, participant burden, inconvenience). Remote biochemical confirmation of self-reported smoking abstinence should be included in smoking cessation studies whenever feasible. However, findings should be considered in the context of challenges to sample return rates. Better reporting guidelines for future studies in this area are needed.

Systematic review of intervention functions, theoretical constructs and cultural adaptations of school-based smoking prevention interventions in low-income and middle-income countries

OBJECTIVE

To identify the approaches and strategies used for ensuring cultural appropriateness, intervention functions and theoretical constructs of the effective and ineffective school-based smoking prevention interventions that were implemented in low-income and middle-income countries (LMICs).

DATA SOURCES

Included MEDLINE, EMBASE, Global Health, PsycINFO, Web of Science and grey literature which were searched through August 2022 with no date limitations.

ELIGIBILITY CRITERIA

We included randomised controlled trials (RCTs) with ≥6 months follow-up assessing the effect of school-based interventions on keeping pupils never-smokers in LMICs; published in English or Arabic.

DATA EXTRACTION AND SYNTHESIS

Intervention data were coded according to the Theoretical Domains Framework, intervention functions of Behaviour Change Wheel and cultural appropriateness features. Using narrative synthesis we identified which cultural-adaptation features, theoretical constructs and intervention functions were associated with effectiveness. Findings were mapped against the capability-motivation and opportunity model to formulate the conclusion. Risk of bias was assessed using the Cochrane risk of bias tool.

RESULTS

We identified 11 RCTs (n=7712 never-smokers aged 11-15); of which five arms were effective and eight (four of the effective) arms had a low risk of bias in all criteria. Methodological heterogeneity in defining, measuring, assessing and presenting outcomes prohibited quantitative data synthesis. We identified nine components that characterised interventions that were effective in preventing pupils from smoking uptake. These include deep cultural adaptation; raising awareness of various smoking consequences; improving refusal skills of smoking offers and using never-smokers as role models and peer educators.

CONCLUSION

Interventions that had used deep cultural adaptation which incorporated cultural, environmental, psychological and social factors, were more likely to be effective. Effective interventions considered improving pupils' psychological capability to remain never-smokers and reducing their social and physical opportunities and reflective and automatic motivations to smoke. Future trials should use standardised measurements of smoking to allow meta-analysis in future reviews.