There is a need for systematic evaluation of treatment of out-patients in mental health services. Very few instruments for such evaluation that has been translated to Norwegian have been properly validated.

To document the psychometric properties of the Norwegian translation of the outcome-measure Clinical Outcomes in Routine Evaluation (CORE-OM).

A clinical sample (N = 528) was collected from out-patient mental health services. A non-clinical convenience sample (N = 473) was also collected. A sub-sample of 81 from the non-clinical sample filled in the questionnaire four times, with one week between tests, alternating between the Norwegian translation and the original English version. The same sub-sample of 81 students was posed a question to measure psychological strain.

There were no significant differences in mean-scores between the sexes, neither in the non-clinical nor in the clinical sample. All mean scores were significantly higher in the clinical than in the non-clinical sample. The cut-off point for the Well-being items was higher for women, while the cut-off point for risk of suicide/harm to others was higher for men. Cut-off scores for Problem-items and Function-items was similar for men and women. The scores increased after exposure to psychological strain. Acceptability, internal consistency, test-retest stability, and the differences between scores in non-clinical and clinical samples were at the same level as in English data. Regarding cut-off scores, these are very similar also.

The Norwegian translation of the CORE-OM have psychometric properties very simialer to the English original, and could be recommended for general use.