Distribution of CORE-OM scores in a general population, clinical cut-off points and comparison with the CIS-R.

BACKGROUND Although measures of psychopathology are designed for use in clinical populations, their meaning derives from comparison with normal populations. AIMS To compare the distribution of scores on the Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM) from a general population sample with the distribution in an aggregated clinical sample to derive recommended cut-off points for determining clinical significance. METHOD The CORE-OM general population sample was based on a weighted subsample of participants in the psychiatric morbidity follow-up survey who completed valid CORE-OM forms following their interview (effective n=535). RESULTS Comparison of the CORE-OM general population sample with a clinical sample aggregated from previous studies (n=10761) yielded a cut-off score of 9.9 on the 0-40 scale of the CORE-OM. The CORE-OM was highly correlated (r=0.77) with the Clinical Interview Schedule-Revised, supporting convergent validity. CONCLUSIONS We recommend rounding the CORE-OM cut-off score to 10. However, cut-off scores must be used thoughtfully and adjusted to fit context and purpose.