CORE-OM, is a common self-report measure of global distress, suitable for use as an initial screening tool and for assessing the response to psychological therapy. The measure has 34 items all answered on the same five level frequency scale asking about the respondent's state over the last week. It was originally designed and developed in response to a research funding call from the UKMental Health Foundation which required that the content must cover domains of well-being, problems, functioning and risk. These were seen as content domains, not as cleanly separablelatent variables or factors, it was never envisaged that such a broad set of issues would show any neat population structure that would emerge in factor analysis.
Copyright status
The instrument has always been free to reproduce on paper, for non-commercial purposes, provided the content was not changed in any way. As of 2015 this licencing has been extended and clarified by adoption of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International licence. The copyright remains with CORE System Trust and it is illegal to change the measure, including to translate it. However, CST are active in supporting translations to their protocol.
Translations
Translations have been completed into 30 languages and a number more are underway. Details at . CORE System Trust welcome contact about further translations through the site and specific pages there have details about particular languages e.g. and and some to particular countries, e.g. .
Short forms and related instruments
There are approved short forms: two 18 item versions launched with the CORE-OM in 1998, the GP-CORE for general population survey work and the CORE-10. In addition the YP-CORE, a 10 item form for young people has been developed based on the CORE-OM, as have two forms for adults with mild to moderate learning difficulties. Comprehensive information about the CORE-OM and CORE is available at https://www.coresystemtrust.org.uk/.
Similar instruments or systems and complementary measures
The CORE system philosophy was that the instruments, and practitioners and researchers should be free to use them as they saw fit: a "bottom up" philosophy rather than one of "top down" usage dictated by politics or health delivery systems. The copyleft status was intended to remove cost barriers to using the instruments while ensuring that they weren't mutated into many non-comparable forms. When the system was launched in 1998 it rapidly became clear that there were several similar initiatives including the highly successful Outcome Measures work, in which the Outcome Measure-45 Outcome Questionnaire 45 led by Professor Michael Lambert in the USA and, also from the USA, the system led by Scott D. Miller and his colleagues all of which share the idea of a central "core" or issues being evaluated. At the same time it was anticipated that such "core" measures would be complemented, particularly in research work, by problem specific measures, perhaps often too long, or too costly for routine service, e.g. the Beck depression Inventory.
Health Economic (QALY) scoring
Work by Ifigenia Mavranezouli, then at the University of Sheffield focusing on health economic evaluation created the CORE-6D scoring of six items of the CORE-OM that converts their scores to a QALY score.
Responding to the COVID-19 pandemic CORE System trust have provided free fillable PDF forms, Microsoft Forms, Qualtrics and LimeSurvey templates. An attempt to provide Google Forms was abandoned when it proved impossible to ensure that practitioners copying the forms would follow the instructions carefully enough to ensure that they didn't share data at the same time as sharing the forms. This experience has been described in a publication. and these resources can be found at the on the CORE/CST web site.
