Patient and referrer satisfaction is regularly used as a feedback instrument in order to evaluate quality from the customer's point of view. Improvement measures are then determined and rigorously implemented. Together with customer satisfaction, the quality of the treatment outcome is the decisive measure of success in rehabilitation. In addition to the current continuous outcome measurement, a multi-year study is being carried out to determine how the outcome quality of inpatient rehabilitation can best be measured. After completion of the study, a standardised process for documentation of the rehabilitation outcome for each patient will be established at the Bellikon Rehabilitation Clinic.