BACKGROUND: Instruments are used for routine outcome monitoring of patients with severe mental illness in order to measure psychiatric symptoms, care needs and quality of life. By adding an instrument for measuring functional remission a more complete picture can be given of the complaints, the symptoms and general functioning, which can give direction to providing care for patients with severe mental illness. AIM: To describe the development and testing of a new instrument of functional remission (FR) among people with a psychotic disorder or another serious mental disorder (SMI) as an addition to the symptomatic remission (SR), according to international criteria. METHOD: The FR-assessment involves assessment by a mental health professional who conducts a semi-structured interview with the patient and his or her family and/or uses patient files relating to the three areas of functioning: daily living and self-care; work, study and housekeeping; and social contacts. These areas are rated on a three-point scale of o: independent; 1: partially independent; 2: dependent. The assessment covers a period of six months, in accordance with the measurement of symptomatic remission and should be part of regular routine outcome monitoring (ROM) procedures. The FR-instrument was used in 2012 with 840 patients from eight Dutch mental care institutions and included a one-year follow-up among 523 patients (response 62%). RESULTS: The results showed that the instrument is relatively easily to complete. It was also relevant for clinical practice, although further research is needed because of the raters' low response. Intra- and inter-rater reliability, discriminating and convergent validity, and sensitivity to change were rated sufficient to good. CONCLUSION: If the FR-instrument becomes part of regular ROM-procedures and is used as a measure of societal participation, it could be a useful addition to current measures of symptomatic remission.</p
