Lung cancer remains the leading cause of cancer mortality worldwide, yet low-dose CT screening — a tool proven to reduce deaths in high-risk adults — reaches far fewer eligible people than it should. Understanding exactly what stops people from participating is critical to designing interventions that actually work, and a new systematic mapping effort offers the clearest picture yet of those barriers and facilitators.
This international scoping review synthesized 39 studies — encompassing quantitative, qualitative, and mixed-methods designs — published between 2013 and 2025, drawing from six major databases and screening over 3,200 records. Using the validated COM-B (Capability-Opportunity-Motivation-Behavior) behavioral framework, researchers coded determinants of LDCT screening participation across multiple domains. On the facilitating side, risk awareness appeared in 15 studies, perceived benefits in 13, and clinician recommendation in 12 — consistently among the strongest drivers of uptake. On the barrier side, misconceptions about screening were cited in 13 studies, competing life priorities in 12, and fear of receiving a positive result in 11, forming a triad of psychological and practical obstacles that suppress participation even among those who intend to screen.
The application of the COM-B model is notable here, as it shifts the analytical lens beyond simple attitudes toward a more granular decomposition of behavioral determinants — distinguishing between what people know, what they can realistically access, and what actually motivates action. This matters because interventions targeting only one domain routinely underperform. The finding that favorable intentions frequently fail to translate into actual screening uptake points to what behavioral scientists call the intention-action gap, a well-documented phenomenon in preventive health. The scoping — rather than systematic — review design limits causal inference, and heterogeneity across study populations (different countries, screening eligibility criteria, and healthcare systems) complicates direct comparisons. Still, the COM-B mapping provides an actionable framework that lung cancer screening programs can use to audit their current outreach and identify specific leverage points. Clinician engagement emerges as perhaps the most modifiable high-impact factor, since a direct physician recommendation consistently amplifies uptake in ways that mass-communication campaigns alone cannot replicate.