Recruitment strategies for lung cancer screening; a randomised trial in the 4-IN-THE-LUNG-RUN study

OBJECTIVE: Invitations to participate in screening programmes are predominantly distributed through traditional paper-based methods. More tailored approaches - incorporating both socioeconomic status- (SES) and sex-specific preferences - may improve programme uptake. This study aims to optimize the recruitment strategy for high-risk individuals in lung cancer screening: the 4-IN-THE-LUNG-RUN trial. METHODS: A total of 336,860 Dutch individuals, aged 60-79 years, were randomised to receive one of three recruitment methods: (1) standard paper, (2) standard online, or (3) tailored online, and invited to participate if they considered themselves eligible. Additionally, there was the option to self-enrol (online). Inclusion criteria for participation were: 1) People who currently smoke or have quit smoking within the past 10 years with ≥ 35 pack-years or 2) a PLCOm2012NoRace risk ≥ 2.60%. RESULTS: Out of 35,755 respondents (10.6%), 15,840 individuals (44.3%) were eligible to participate. While the absolute number of eligibles was highest in the paper-based group (N = 5079), exceeding the online groups by 13.1% and 17.0%, the proportion of eligible was significantly lower (37.8%) compared with both online groups (ONLINE: N = 4412, 45.0%; TAILORED: N = 4214, 45.0%; p < 0.001). Overall, a significantly larger proportion of individuals from the low SES group (40.0%) were eligibles relative to the middle (26.5%) and high (33.5%) SES (p < 0.001). The proportion of low SES eligibles was significantly higher in the paper-based group (42.8%) compared to both online groups (ONLINE: 37.0% and TAILORED: 38.6%; p < 0.001). Self-registered eligibles had a similar low SES participant proportion (42.6%) as the paper-based group. Gender distributions were comparable across recruitment methods (p = 0.137). CONCLUSION: Online recruitment strategies may effectively recruit high-risk individuals for low-dose CT screening, including older elderly and those from lower SES, and may be associated with lower resource requirements compared with paper-based approaches. Nevertheless, retaining a paper-based option is essential to ensure inclusive and equitable access to lung cancer screening.