Clinical Outcomes in Routine Evaluation—outcome measure

Abstract

The Clinical Outcomes in Routine Evaluation—outcome measure (CORE-OM) is a widely utilized 34-item self-report instrument developed to assess the overall effectiveness and outcome of psychological therapies and mental health services in routine clinical settings. Designed by Clinical Outcomes in Routine Evaluation researchers, the scale provides a comprehensive snapshot of a client’s distress and functioning across four major dimensions: subjective well-being, problems/symptoms, life functioning, and risk/harm. The CORE-OM is distinguished by its practical utility, ease of administration, and strong psychometric properties, making it a standard tool for monitoring change and evaluating service provision.

Keywords

CORE-OM, clinical outcome measure, routine evaluation, psychological distress, psychotherapy assessment, subjective well-being, risk assessment, mental health service evaluation.

Authors

Evans, C., Mellor-Clark, J., Margison, F., Barkham, M., Audin, K., Connell, J., McGrath, G.

Purpose

The primary purpose of the CORE-OM is to provide a standardized, brief, and reliable measure of client psychological status that can be used routinely across diverse mental health settings, including primary care, counseling services, and specialized psychotherapy units. It is specifically intended to track changes in client well-being and distress levels from intake through treatment termination, thereby facilitating outcomes monitoring and service evaluation.

The instrument allows clinicians and researchers to generate mean scores that reflect the severity of a client’s difficulties over the preceding week. This routine monitoring helps inform clinical decisions, ensures accountability within services, and contributes to the broader understanding of effective psychological interventions.

Construct

The CORE-OM measures a broad construct of psychological distress and functional impairment, structured around four primary domains, designed to capture the complexity of therapeutic change:

• Subjective well-being: Measures positive aspects of mental health, such as feelings of happiness, optimism, and self-worth.
• Problems/symptoms: Captures specific symptomatic distress related to anxiety, depression, physical discomfort, and unwanted thoughts.
• Life functioning: Assesses difficulties in daily social and occupational roles, including coping mechanisms and social isolation.
• Risk/harm: Evaluates potential harm to self (suicidality, self-harm) and harm to others (violence, intimidation).

The overall score provides a measure of global severity, while the sub-scores allow for detailed analysis of specific areas of concern or improvement. The focus on both symptomatic distress and functional improvement aligns with modern definitions of successful therapeutic outcomes.

Validity

Extensive research supports the validity of the CORE-OM. The instrument demonstrates strong concurrent and convergent validity, showing high correlations with established measures of general psychological distress, such as the General Health Questionnaire (GHQ-12) and the Beck Depression Inventory (BDI).

Furthermore, the CORE-OM exhibits excellent sensitivity to change (or responsiveness), confirming its utility as an outcome measure. Studies routinely show that scores decrease significantly following successful therapeutic intervention, indicating that the scale accurately captures clinically meaningful improvements. Discriminant validity is also supported by low correlations with measures of unrelated constructs.

Reliability

The reliability of the CORE-OM is consistently reported as high across clinical and non-clinical populations. The measure exhibits excellent internal consistency, with Cronbach’s alpha coefficients typically exceeding 0.90 for the total score, suggesting that the items reliably measure a single underlying construct of psychological distress.

Test-retest reliability is generally moderate to high, confirming the stability of the measure over short periods when no clinical intervention has occurred. This stability ensures that score changes observed during treatment are likely due to therapeutic effects rather than measurement error.

Factor Analysis

Initial factor analyses, including those detailed in the 2002 publication by Evans et al., typically support a robust hierarchical structure. While a strong single factor representing overall psychological distress accounts for most of the variance, confirming its utility as a global outcome measure, factor analysis also supports the extraction of the four primary subscales: Subjective well-being, Problems/symptoms, Life functioning, and Risk/harm.

More sophisticated techniques, such as Confirmatory Factor Analysis (CFA), have confirmed that the four-factor model provides a good fit for the data, supporting the theoretical structure used in calculating the domain scores.

Instrument

Test Type: Self-report questionnaire, Psychological Outcome Measure

Format: 34 items, 5-point Likert scale, typically completed in 5–10 minutes.

Language Available: English (original), with numerous translations available and validated across Europe and internationally.

Population Group: Clinical and non-clinical populations seeking or receiving mental health treatment.

Age Group: Typically utilized for adults (17 years and older).

Population Details: Suitable for use in diverse settings including counseling, psychotherapy, primary care mental health services, and specialized psychiatric units.

Test Methodology: Clients respond based on how often they have experienced the described feeling or behavior over the last week, using a scale from 0 (“Not at all”) to 4 (“Most or all the time”). Scoring involves calculating the mean item score; specific items are reverse coded.

Keywords

Clinical Outcomes in Routine Evaluation, CORE-OM, psychological assessment, outcomes monitoring, therapeutic change, mental health measurement, self-report scale.

Authors

Author ORCID Identifier: Not available/Not provided

Affiliation Email addresses: [email protected] (Dr. Chris Evans)

Correspondence Address: Dr. Chris Evans, Institute of Group Analysis, Nottinghamshire Personality Disorder and Development network, mandala Centre.

Permissions & Fee and Test Year

The CORE-OM is generally available for use without charge for non-commercial clinical practice and academic research, a key factor in its widespread adoption. Commercial use or modifications typically require formal licensing. The initial publication and release year for the scale was 2000.

The original PDF of the instrument can be downloaded here: https://www.sussex.ac.uk/webteam/gateway/file.php?name=core.pdf&site=322

Scoring Instructions:

Responses are scored on a 5-point frequency scale: 0=Not at all, 1= Only Occasionally, 2=Sometimes, 3= Often, 4= Most or all the time.

The following items are reverse coded to maintain consistency in scoring direction (higher score indicating greater difficulty/distress): 3, 4, 7, 12, 19, 21, 31, and 32.

Reference’s

• Evans, C., J. Mellor-Clark, F. Margison, M. Barkham, K. Audin, J. Connell and G. McGrath (2000). CORE: Clinical Outcomes in Routine Evaluation. Journal of Mental Health 9(3): 247-255.

• Evans, C., J. Connell, M. Barkham, F. Margison, G. McGrath, J. Mellor-Clark and K. Audin (2002). “Towards a standardised brief outcome measure: psychometric properties and utility of the CORE-OM.” British Journal of Psychiatry 180(1): 51-60.

Items of the Clinical Outcomes in Routine Evaluation—outcome measure

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

1. I have felt terribly alone and isolated
2. I have felt tense‚ anxious or nervous
3. I have felt I have someone to turn to for support when needed
4. I have felt O.K. about myself
5. I have felt totally lacking in energy and enthusiasm
6. I have been physically violent to others
7. I have felt able to cope when things go wrong
8. I have been troubled by aches‚ pains or other physical problems
9. I have thought of hurting myself
10. Talking to people has felt too much for me
11. Tension and anxiety have prevented me doing important things
12. I have been happy with the things I have done.
13. I have been disturbed by unwanted thoughts and feelings
14. I have felt like crying
15. I have felt panic or terror
16. I made plans to end my life
17. I have felt overwhelmed by my problems
18. I have had difficulty getting to sleep or staying asleep
19. I have felt warmth or affection for someone
20. My problems have been impossible to put to one side
21. I have been able to do most things I needed to
22. I have threatened or intimidated another person
23. I have felt despairing or hopeless
24. I have thought it would be better if I were dead
25. I have felt criticised by other people
26. I have thought I have no friends
27. I have felt unhappy
28. Unwanted images or memories have been distressing me
29. I have been irritable when with other people
30. I have thought I am to blame for my problems and difficulties
31. I have felt optimistic about my future
32. I have achieved the things I wanted to
33. I have felt humiliated or shamed by other people
34. I have hurt myself physically or taken dangerous risks with my health