The project consists of a scientific evaluation of the Fedris program for the secondary prevention of low back pain (LBP). The overall objective is to evaluate the efficiency of this intervention program in terms of sickness absence and health care expenditure, compared to no intervention or usual care. Secondary analyses will be conducted on the data collected by Fedris among the employees who participated in the program (treatment group) and compared with general data from the health insurance funds (control group).  In addition, a qualitative research will be set up among these employees and their caregivers . Finally, a protocol for a randomized clinical trial will be developed to compare in a longitudinal way the impact of an intervention programme LBP versus care as usual.