How is CORE Used?

When the CORE-OM was developed, the aim was for practitioners to calculate a mean item score by summing the individual item scores and dividing by the total number of questions answered to yield a mean score ranging from 0 to 4. Over the years, however, the system has changed to take into account feedback from practitioners who have found it easier to assign meaning to whole numbers rather than fractions. It is now standard practice to multiply the mean item score by 10, to give the clinical score.

The therapist can examine the extent to which a client's CORE-OM score is associated with a 'clinical population' by comparing the score at referral with a national 'clinical cut-off' score of 10. This clinical cut-off was derived from studies asking large samples of the UK population to complete the questionnaire and comparing their scores statistically with those for large samples of clients in therapy. Four bands of scores above the clinical cut-off have been established as representative of mild (green), moderate (orange) and severe (red) levels of distress (see look up scale).

For practitioners to assess meaningful improvement over the course of therapy, two numeric changes are essential: reliable change and clinically significant change.

  • Reliable change is change that exceeds that which might be expected by chance alone or measurement error and for the CORE-OM is represented by a change of 5 or more in the clinical score.
  • Clinically significant change is indicated when a client's CORE score moves from the clinical to the non-clinical population (ie. Client scores above 10 at intake and below 10 after therapy)

The family of CORE measures

For assessment and outcome, the full CORE-OM is recommended, or the full version can be used without the risk items (CORE-NR). Several shorter forms of the CORE-OM have also been derived from it for screening and research purposes.

  • Two parallel short versions (CORE-18 A & B) were designed so that they could be alternated in repeated sessions for research studies in order to reduce memory effects.
  • There is a version for use in the general population (CORE-GP) comprising 14 items derived from the CORE-OM.
  • Further versions, such as YP-CORE for young people, have been developed for particular groups and an expanding programme of work is developing translations of CORE-OM for ethnic and European languages (translations into many languages are already available)

In 2006, at the request of the CORE User Network the CORE System was enhanced by the addition of a 10-item version for screening and review (CORE-10), and a 5-item version for tracking recovery and improvement (CORE-5). These new additional outcome monitoring and management tools form essential resources for the new on-line generation of IT support software CORE Net.

Full List of Measures »

All CORE measures can be downloaded as forms and used free of charge under the terms of the CORE copyright.



CORE System Measurement Tools CORE Software, CORE PC, CORE Net CORE Training, Research and Consultancy