ABSTRACT Introduction The role of identity is increasingly a subject of study in smoking cessation research. However, there is still no standard approach to accounting for the construct of identity. The present review was set to identify theories used in peer-reviewed studies to inform the concept of identity in smoking cessation research. Methods A systematic search strategy containing MeSH-based terms focusing on identity and smoking cessation was applied to three databases on February 15, 2026. Results Thirty-one studies were included, using qualitative, experimental, mixed-methods and software-development designs. Nine theories were used: the PRIME theory of motivation (n = 11); Theory of Planned Behaviour (n = 6) and/or Theory of Reasoned Action (n = 1); Social Identity Theory (n = 7) and/or Self-Categorisation Theory (n = 2); Social Identity Threat (n = 4); Symbolic Interaction Theory alone (n = 1) or in combination with Integrative Theory of Identity (n = 1); and Cognitive Dissonance Theory (n = 1). These theories served as theoretical frameworks or foundations for developing hypotheses, guiding data collection and analysis, and conceptualising identity. Despite differences in methods and outcomes, studies highlight that identity plays an important role in smoking cessation. Conclusions Identified identity theories in smoking cessation research fall broadly into cognitive or social categories, but there is no consistent approach to selecting or operationalising them. Findings are limited by the number and heterogeneity of studies, but suggest identity is a valuable target for enhancing and developing personalised smoking cessation interventions.
Simionato et al. (2026) studied this question.