Screening at-risk subjects with low-dose computed tomography (CT) efficiently reduces lung cancer specific mortality. However screening efficiency relies on the at-risk population's criteria definition and its participation rate to the screening. In France, there are concerns regarding the participation rates to national cancer screening that are quite low (around 50% and 32% of the eligible population for breast cancer and colorectal cancer respectively). Before organizing national lung cancer screening it is then crucial to determine the factors impacting the at-risk subjects willingness to participate in lung cancer screening.

The Lyon University Hospital is the second biggest hospital in France with more than 23,000 employees distributed among more than 160 professions representing every level of education or working conditions. Its population is heterogeneous and wide enough to perform a prevalence study assessing the willingness to participate among the at-risk population.

ILYAD is a prospective study performed by anonymous questionnaires that will be submitted to the 23,000 employees of the Lyon University Hospital. The study main objective is to evaluate the at-risk population presence in the Lyon University Hospital population, as defined by NELSON criteria and selection criteria for lung cancer screening (PLCOm2012 scoring), and its willingness to participate to a lung-cancer screening with low-dose CT. This might help further efficient national lung cancer screening campaign organization.

Inclusion Criteria:

• Aged ≥ 18 years old
• Employee from the Lyon University Hospital (receiving salary from the Lyon University Hospital)
• Person who has willingness to respond the survey

Exclusion Criteria:

• Employees not hired by the Lyon University Hospital
• Employees who have not willingness to participate in the survey

The Civil Hospices of Lyon is the second largest university hospital in France, with 23000 staff.