CORE-10 Calculator

What is the CORE-10?

The Clinical Outcomes in Routine Evaluation (CORE-10) is a ten-item self-report measure designed to assess psychological distress and monitor clinical outcomes in therapy. Developed by Connell and Barkham as a brief version of the 34-item CORE-OM (CORE Outcome Measure), the CORE-10 was created for the CORE System Trust to provide a short, clinically useful measure that could be administered at every session.

The CORE-10 covers multiple domains of psychological functioning: subjective wellbeing, commonly experienced problems (anxiety, depression, physical symptoms, trauma), functioning (close relationships, general functioning, social functioning), and risk (to self). Each item is scored from 0 to 4, with three items reverse-scored, yielding a total score between 0 and 40. The instrument is licensed under Creative Commons (CC BY-NC-ND 4.0) and is free for clinical use.

Development and Validation

The CORE-10 was derived from the CORE-OM by selecting ten items that best represented the four domains of the parent instrument while maintaining strong psychometric properties. The development was documented in the CORE-10 User Manual published by Connell and Barkham in 2007.

The ten items were selected to provide adequate coverage of the CORE-OM domains while minimising respondent burden. Three items are positively worded and reverse-scored (items 3, 4, and 7), which helps reduce response bias. The CORE-10 includes one risk item (item 9), which asks about thoughts of hurting oneself, ensuring that risk is captured even in this brief version.

Validation studies have demonstrated good internal consistency and strong correlations with the full CORE-OM (typically r > 0.90). The CORE-10 has been adopted widely in UK NHS services, IAPT (Improving Access to Psychological Therapies) programs, and counselling services internationally. Its sensitivity to change makes it particularly useful for tracking therapy outcomes.

How CORE-10 Scoring Works

The CORE-10 uses a five-point frequency scale for each item:

0 = Not at all 1 = Only occasionally 2 = Sometimes 3 = Often 4 = Most or all of the time

Three items (3, 4, and 7) are reverse-scored: the response value is subtracted from 4 (so "Not at all" = 4, "Most or all of the time" = 0 for these items).

Total scores range from 0 to 40. The clinical mean score is calculated by dividing the total by 10. Published severity thresholds based on total score are:

0-5: Healthy — below clinical threshold 6-10: Low level — below clinical threshold 11-15: Mild — above clinical cutoff, clinical follow-up recommended 16-20: Moderate — clinical follow-up recommended 21-25: Moderate to severe — clinical follow-up recommended 26-40: Severe — comprehensive clinical assessment recommended

The clinical cutoff is a total score of 10 (mean score of 1.0). Scores at or above this threshold are considered to be in the clinical range. Item 9 (risk item — "I have thought of hurting myself") warrants attention regardless of the total score.

Clinical Applications

The CORE-10 is widely used in clinical practice for outcome monitoring and service evaluation. Its primary applications include:

Session-by-session monitoring in therapy. The CORE-10's brevity makes it practical for routine administration at every session, enabling clinicians and clients to track progress throughout the course of care.

Pre- and post-treatment outcome measurement. The CORE-10 provides a standardised measure of change that can be used for clinical governance, service evaluation, and quality improvement.

Initial screening and triage. The clinical cutoff score supports identification of individuals with clinically significant levels of distress.

Service-level benchmarking. The CORE System provides normative data from large clinical and non-clinical samples, enabling services to compare their outcomes against published benchmarks.

The inclusion of a risk item (item 9 — "I have thought of hurting myself") ensures that self-harm risk is flagged even in this brief measure. Any positive response to item 9 should be explored further by a qualified practitioner.

CORE-10 in Australian Practice

In Australia, the CORE-10 is used in psychology, counselling, and psychotherapy services as an outcome monitoring tool. While the K-10, PHQ-9, and GAD-7 are the primary instruments recommended under the Better Access initiative, the CORE-10 is valued in Australian practice for its broad coverage of psychological functioning — spanning wellbeing, symptoms, functioning, and risk in a single brief measure.

The CORE-10 is particularly popular in Australian university counselling services, employee assistance programs (EAPs), and private practice settings where session-by-session monitoring is emphasised. Its sensitivity to change makes it useful for demonstrating treatment outcomes.

The CORE System Trust permits free reproduction of the CORE-10 in software and clinical settings under Creative Commons licensing, making it accessible for Australian practitioners. The instrument is available from the CORE System Trust website (coresystemtrust.org.uk).