Background: Participation rate to lung cancer screening (LCS) programs is a key factor of efficacy. Lyon University Hospital (LUH) is the second largest university hospital in France. It hosts 26,000 staffs. The ILYAD (Initiative LYonnaise pour l’Amorçage du Dépistage) study aim to assess the participation rate of a “captive” population submitted to various stimuli of communication on LCS program.  
Objective: Measure participating rate to LCS in a “captive” population, and assess various communication approaches.
Method: In a previous work, we assessed the number of eligible employees at LUH using a questionnaire sent to all staff. We defined that 838 peoples among 26,954 staffs were found eligible to LCS according to NESLON criteria (50-74 yeasr-old, current or former smokers who quit since less than 15 years, with ≥15 cigarettes per day ≥25 years or ≥10 cigarettes per day ≥30 years) which were recommended at this time. The, we designed an LCS program dedicated to staffs from LHU. We provided specific email address, phone number, and an online tool. We applied three communication methods for participants recruitment. We started with common displays (flyers, posters) and general emailing. Then, we involved managers of the departments identified with high-risk employees and occupational medicine. Finally, we used specially trained nurses to meet the employees in their daily routine.
Results: From September 2022 to May 2024, 141 participants were included, resulting in a participating rate of 16.8%. They were manly female (75.9%) with a mean age at 56.3yo (SD 3.8). 85 (59%) were included during the first period (common displays and emails), 17 (12%) during the second (targeting high-risk), and 44 (30%) during the third (face to face meeting). 70% participants contacted us through the online tool. 39 participants (28.3%) were eligibles according to PLCOm2012norace score ≥1,51%. 77 participants (56.6%) were current smokers with a mean Pack-year of 29.3 (SD 9.6). 45% were not caregivers. We found that 27 (19.4%) participants had a FEV1/FCV ratio <70%, 40 (29.4%) had a blood pressure measure >140/90. Attend to smoking cessation visit was high (98%) as well as adhesion rate at CT scan at 1 year (91.3%) although results need to be consolidated on the full dataset.  Full results with results on the second (and final) round will be presented at meeting.
Conclusion:  Despite a population of healthcare employees and different communication strategies tested, our results showed a low LCS participation rate. These results enhanced the fact that population adherence to LCS program will be a critical issue to address in order to improve screening efficiency.