Introduction In France, governments have been developing health at work plans since the early 2000s. The agricultural sector is no exception. In order to set up such a plan, the French agricultural health insurance fund (Caisse Nationale de la Mutuelle Sociale Agricole) has developed a range of managerial processes. These include outcomes to be achieved, which are in turn based on measurable indicators. The aim of the study is to assess the impact of these managerial processes on prevention.

Methods This research is based on non-participant observations that have been conducted within 5 health at work prevention services over a period of 10 months. Observations have been complemented by 2 series of interviews that have been conducted within the above mentioned services (n=34) and at national level (n=3). Two analyses of these interviews have been carried out. A first analysis has been conducted using Alceste software in order to identify semantic universes. The second analysis was a thematic one. Observations have enabled to relate discourses on the one hand and actual prevention work activities on the other.

Results Effects induced by measurable outcomes cause several types of reactions, among which: the questioning of professional identities, the emergence of local forms of negotiation, internal tensions between the members of health at work services.

Conclusion When intervening in work settings, health prevention professionals used to be very critical of the use of measurable outcomes. The ultimate paradox is that it is now their turn to submit to similar organisational and managerial constraints.