Coercion perceived by psychiatric inpatients is not exclusively determined by formal measures such as involuntary admissions, seclusion or restraint, but is also associated with patients' characteristics and professionals’ attitude.

This study examined how inpatients’ involvement in the decision making process, the respect of their decision making preference, and their feeling of having been treated fairly mediate the relationship between involuntary hospitalisation and perceived coercion both at admission and during hospital stay.

Mediation analysis were performed in order to study the relationship between involuntary hospitalisation and perceived coercion among 230 patients, voluntarily and involuntarily admitted in six psychiatric hospitals.

32.2% of the participants were involuntarily hospitalised. Taken individually, stronger participants’ involvement in decision making process, better respect for their decision making preference and higher level of perceived fairness partially mediated the relationship between involuntary hospitalisation and perceived coercion by reducing the level of the latter both at admission and during the hospitalisation. In multiple mediator models, only involvement and respect played an important role at admission. During the hospitalisation, perceived fairness was the most relevant mediator, followed by involvement in decision making.

During psychiatric hospitalisation patients’ involvement in decision making, respect of their decision making preference and perceived fairness determined the relationship between involuntary hospitalisation and perceived coercion, but not in the same way at admission and during the stay. Involving patients in decision making and treating them fairly may be more relevant than taking account of their decision making preference in order to reduce perceived coercion.