Clinical Outcomes in Routine Evaluation (CORE-OM)

Abstract

The Clinical Outcomes in Routine Evaluation (CORE-OM) is a 34-item, self-report measure designed to assess the severity of psychological distress experienced by clients receiving therapeutic services. It is typically administered both before and after psychological interventions to quantify treatment outcomes and measure the degree of clinical change.

The instrument captures the client’s experience over the last week across four crucial dimensions of functioning and well-being: Subjective well-being, Problems/symptoms, Life functioning, and Risk/harm. Comparison of pre- and post-therapy scores provides a standardized measure of ‘outcome’ utilized for routine monitoring and clinical governance.

Keywords

CORE-OM, Psychological Outcomes, Psychological distress, Outcome Measures, Routine Evaluation, Clinical Assessment, Psychological interventions, Self-report measure.

Authors

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

Purpose

The primary purpose of the CORE-OM is to provide a standardized, brief, and reliable method for measuring the effectiveness of psychological interventions in routine clinical settings. By comparing scores obtained prior to treatment (baseline) and following the final session (post-treatment), clinicians and researchers can determine the degree of change in a client’s overall level of psychological distress and functioning.

Its utility lies in its ability to serve as an indispensable tool for routine outcome monitoring, facilitating clinical governance and quality assurance across various mental health services, particularly within systems like the UK National Health Service (NHS).

Construct

The CORE-OM is constructed to measure the overarching construct of global psychological distress and well-being. It is a multi-dimensional instrument encompassing both positive and negative aspects of mental health and functioning. The scale achieves this by dividing the 34 items into four distinct, yet interrelated, subscales or domains of outcome.

These four dimensions provide a comprehensive clinical profile: Subjective well-being (the client’s general positive outlook), Problems/symptoms (the presence and severity of emotional and psychological symptoms), Life functioning (the client’s ability to cope with daily life and social roles), and Risk/harm (the presence of self-harm, suicidal ideation, or harm to others).

Validity

The CORE-OM demonstrates robust validity supported by extensive testing across diverse populations. Initial validation studies included samples from the general population, as well as specific clinical cohorts within the UK’s National Health Service (NHS), spanning both primary and secondary care settings, and specifically validating its use with older adults. This broad validation confirms the scale’s applicability and relevance across various levels of clinical severity.

Clinical normative data were established based on a sample (N = 890) drawn from 21 sites across England, predominantly within the NHS structure. This population comprised users waiting for or receiving a wide array of psychological interventions. This normative data, reported in the CORE SYSTEM USER MANUAL, is critical for computing percentile ranks and accurately interpreting a client’s score relative to others seeking psychological help, where a percentile of 50 represents the average distress level of the clinical sample.

Reliability

The CORE-OM is recognized for its strong psychometrics, which include high internal consistency and reliability, making it suitable for measuring change over time. Although specific reliability coefficients (such as internal consistency measures like Cronbach’s alpha or test-retest reliability) are detailed in the full CORE System User Manual, the instrument is widely utilized due to its demonstrated capacity to consistently measure the underlying construct of psychological distress.

The consistent structure and standardized scoring methods contribute significantly to its reliability in routine clinical practice, ensuring that observed differences in scores between pre- and post-treatment administrations are attributable to genuine clinical change rather than random measurement error.

Factor Analysis

The structure of the CORE-OM is fundamentally based on a four-factor model, reflecting the distinct theoretical domains captured by the measure. Factor analysis confirmed the utility of dividing the 34 items into the four principal subscales: Subjective well-being, Problems/symptoms, Life functioning, and Risk/harm.

The subscales and their corresponding items are:

• Subjective well-being: items 4, 14, 17, 31.
• Problems/symptoms: items 2, 5, 8, 11, 13, 15, 18, 20, 23, 27, 28, 30.
• Life functioning: items 1, 3, 7, 12, 10, 19, 21, 25, 26, 29, 32, 33.
• Risk/harm: items 9, 6, 16, 22, 24, 34.

While the scale yields a single Total Raw Score (ranging from 0 to 136, where higher scores indicate poorer functioning), the underlying factor structure allows for detailed analysis of change within these specific clinical domains, enhancing its utility beyond a simple global measure.

Instrument

Test Type: Self-report measure of psychological outcome and routine monitoring.

Format: 34 items scored on a 5-point Likert scale (0 = Not at all, 4 = Most or all the time). Scores are presented as a Total Raw Score (0–136) or as a Mean Score (0–4), representing the client’s average answer.

Language Available: English (Primary). The CORE system has been widely translated for international use.

Population Group: Individuals seeking psychological intervention for mental health concerns.

Age Group: Typically utilized with adults and older adolescents, validated across a range of adult age groups, including older adults.

Population Details: Clinical populations in primary and secondary care settings, including those within the NHS, encompassing diverse diagnoses and intervention types (N = 890 for clinical norms).

Test Methodology: Clients retrospectively rate their experience over the last week. The measure is designed for repeated administration (pre- and post-treatment) to track clinical change.

Keywords

Outcome Monitoring, Mental Health Assessment, CORE system, Psychometrics, Subjective Well-being, Risk assessment, Clinical Change Index, NHS.

Authors

Author ORCID Identifier: Not provided in source material.

Affiliation Email addresses: Not provided in source material.

Correspondence Address: Not provided in source material.

Permissions & Fee and Test Year

The CORE-OM was initially published and validated in academic literature in 2002 (Evans et al., 2002). The CORE system is overseen by the CORE System Trust. The measure is often freely available for use in non-profit, NHS, and academic research settings, but specific permissions regarding commercial use, modification, or integration into proprietary software should be sought directly from the CORE System Trust.

Reference’s

Evans C, Connell J, Barkham M, Margison F, McGrath G, Mellor-Clark J, Audin K. Towards a standardised brief outcome measure: psychometric properties and utility of the CORE-OM. Br J Psychiatry. 2002 Jan;180:51-60.

Items of the Clinical Outcomes in Routine Evaluation (CORE-OM)

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

This form has 34 statements about how you have been OVER THE LAST WEEK. Please read each statement and think how often you felt that way last week. Then tap the box which is closest to this.