Outcome Measure
Clinical Outcomes in Routine Evaluation
What it measures?
- The CORE-OM aims to capture the ‘core’ of client distress and provide a global index of distress across a variety of dimensions including subjective well-being, commonly experienced problems/symptoms, life and social functioning, and risk to self and others.
- It is suitable as an initial screening tool and may be used to effectively measure the outcomes of psychological interventions and therapies (Dogmanas et al., 2022).
Who is it for?
Recommended for use in people aged 16 years and above. A version of the CORE-OM for young people exists, intended for use in people aged 11 - 16 years old (YP-CORE; Twigg et al., 2009)
Instrument Quality
- The CORE-OM is widely adopted in outpatient services and in psychotherapy research (Dogmanas et al., 2022). It is used to track client progress over time and benchmark patient outcomes at clinical and system levels (Barkham et al., 2006; 2007). The CORE-OM is pan-theoretical (i.e., not based on a particular theory) and pan-diagnostic (i.e. not used to obtain a diagnosis of a specific disorder) in design (Evans et al., 2002; Dogmanas et al., 2022).
Structure
- 34 items - subjective well-being (4), problems/symptoms (12), life functioning (12), risk (6)
- 5-point Likert scale
- Respondents asked how frequently they have felt a certain way ranging from 0 (not at all) to 4 (most or all the time) over the last week (e.g. I have felt tense, anxious or nervous)
Scoring instructions
- For both the overall measure of distress and dimension subscales, the total score is calculated by summing the response values of all 34 items.
- Total mean score is calculated by dividing the total score by the number of completed item responses.
- Overall total scores range from 0 - 136, with a mean score range of 0 - 4.
- Well-being total scores range from 0 - 16, with a mean score range of 0 -4.
- Problem/symptoms total scores range from 0 - 48, with a mean score range of 0 - 4.
- Functioning total scores range from 0 - 48, with a mean score range of 0 - 4.
- Risk total scores range from 0 - 24, with a mean score range of 0 - 4. Mean scores are then generally multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al , 2006)
| Subscale | Item number |
|---|---|
Functioning |
1,3,7,10,12,19,21,25,26,29,32,33 |
Well-being |
4,14,17,31 |
Risk |
6,9,16,22,24,34 |
Full-scale (CORE-OM) |
1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34 |
Problems |
2,5,8,11,13,15,18,20,23,27,28,30 |
Score Interpretation
What higher scores mean?
- Problem scored i.e., higher scores indicate more problems / poorer overall functioning (Evans et al., 2002).
Identifying risk
A patient may be at risk if they endorse any of the following ‘red flag’ items. Further risk assessment should be undertaken.
| Item number | Item content |
|---|---|
| 6 | I have been physically violent to others |
| 9 | I have thought of hurting myself |
| 16 | I made plans to end my life |
| 22 | I have threatened or intimidated another person |
| 24 | I have thought it would be better if I were dead |
| 34 | I have hurt myself physically or taken dangerous risks with my health |
How to assess symptom severity & change?
| Description | Score Range | |
|---|---|---|
| Below normative mean | 0 | |
| Normative mean | 8.5 | |
| 1 SD above normative mean | 15 | |
| 2 SD above normative mean | 21.5 | |
| Maximum | 40 |
| Description | Score Range | |
|---|---|---|
| Below normative mean | 0 | |
| Normative mean | 9.1 | |
| 1 SD above normative mean | 17.4 | |
| 2 SD above normative mean | 25.7 | |
| Maximum | 40 |
Severity ranges
Values for the normative mean and standard deviation are derived from three samples: (A) 691 university students (aged 17-43); (B) 55 university students (aged 20-45); (C) 360 from a sample of convenience of therapists, researchers, colleagues, friends and relatives (aged 14-45; Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006).
Reliable change and clinically significant improvement
Wampold et al (2001) conducted a meta analysis of psychotherapy outcome studies and noted that the average improvement was reflected in an effect size (ES) of .80. Because a change of 1 SD corresponds to an ES of 1.0, and .80 is considered to be a large ES, Wise (2004) concludes that a change of 1 SD is a defensible indicator of clinically significant change.
Mean
| Sample | Mean | Comments |
|---|---|---|
| Clinical | 23.7 | Data was derived from 23 sites (n = 890; aged 16-78), the majority of which were within the NHS, but included one university student counselling service and one staff support service. Data was obtained during pre-treatment or first treatment session (Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006). |
| Normative | 9.1 | Data was derived from three samples: (A) 691 university students (aged 17-43); (B) 55 university students (aged 20-45); (C) 360 from a sample of convenience of therapists, researchers, colleagues, friends and relatives (aged 14-45; Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006). |
Standard Deviation
| Sample | Mean | Comments |
|---|---|---|
| Clinical | 9.6 | Data was derived from 23 sites (n = 890; aged 16-78), the majority of which were within the NHS, but included one university student counselling service and one staff support service. Data was obtained during pre-treatment or first treatment session (Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006). |
| Normative | 8.3 | Data was derived from three samples: (A) 691 university students (aged 17-43); (B) 55 university students (aged 20-45); (C) 360 from a sample of convenience of therapists, researchers, colleagues, friends and relatives (aged 14-45; Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006). |
Reliability
| Value | Comments |
|---|---|
| 0.75 | Internal consistency reliability of the clinical sample is noted. Non-clinical sample reliability is 0.77 (Evans et al., 2002). |
| Description | Score Range | |
|---|---|---|
| Below normative mean | 0 | |
| Normative mean | 2 | |
| 1 SD above normative mean | 6.5 | |
| 2 SD above normative mean | 11 | |
| Maximum | 40 |
Severity ranges
Values for the normative mean and standard deviation are derived from three samples: (A) 691 university students (aged 17-43); (B) 55 university students (aged 20-45); (C) 360 from a sample of convenience of therapists, researchers, colleagues, friends and relatives (aged 14-45; Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006).
Reliable change and clinically significant improvement
Wampold et al (2001) conducted a meta analysis of psychotherapy outcome studies and noted that the average improvement was reflected in an effect size (ES) of .80. Because a change of 1 SD corresponds to an ES of 1.0, and .80 is considered to be a large ES, Wise (2004) concludes that a change of 1 SD is a defensible indicator of clinically significant change.
Mean
| Sample | Mean | Comments |
|---|---|---|
| Clinical | 6.3 | Data was derived from 23 sites (n = 890; aged 16-78), the majority of which were within the NHS, but included one university student counselling service and one staff support service. Data was obtained during pre-treatment or first treatment session (Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006). |
| Normative | 2 | Data was derived from three samples: (A) 691 university students (aged 17-43); (B) 55 university students (aged 20-45); (C) 360 from a sample of convenience of therapists, researchers, colleagues, friends and relatives (aged 14-45; Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006). |
Standard Deviation
| Sample | Mean | Comments |
|---|---|---|
| Clinical | 7.5 | Data was derived from 23 sites (n = 890; aged 16-78), the majority of which were within the NHS, but included one university student counselling service and one staff support service. Data was obtained during pre-treatment or first treatment session (Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006). |
| Normative | 4.5 | Data was derived from three samples: (A) 691 university students (aged 17-43); (B) 55 university students (aged 20-45); (C) 360 from a sample of convenience of therapists, researchers, colleagues, friends and relatives (aged 14-45; Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006). |
Reliability
| Value | Comments |
|---|---|
| 0.79 | Internal consistency reliability of the clinical sample is noted. Non-clinical sample reliability is 0.79 (Evans et al., 2002). |
| Description | Score Range | |
|---|---|---|
| Below normative mean | 0 | |
| Normative mean | 7.6 | |
| 1 SD above normative mean | 13.5 | |
| 2 SD above normative mean | 19.4 | |
| Maximum | 40 |
Severity ranges
Values for the normative mean and standard deviation are derived from three samples: (A) 691 university students (aged 17-43); (B) 55 university students (aged 20-45); (C) 360 from a sample of convenience of therapists, researchers, colleagues, friends and relatives (aged 14-45; Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006).
Reliable change and clinically significant improvement
Wampold et al (2001) conducted a meta analysis of psychotherapy outcome studies and noted that the average improvement was reflected in an effect size (ES) of .80. Because a change of 1 SD corresponds to an ES of 1.0, and .80 is considered to be a large ES, Wise (2004) concludes that a change of 1 SD is a defensible indicator of clinically significant change.
Mean
| Sample | Mean | Comments |
|---|---|---|
| Clinical | 18.6 | Data was derived from 23 sites (n = 890; aged 16-78), the majority of which were within the NHS, but included one university student counselling service and one staff support service. Data was obtained during pre-treatment or first treatment session (Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006). |
| Normative | 7.6 | Data was derived from three samples: (A) 691 university students (aged 17-43); (B) 55 university students (aged 20-45); (C) 360 from a sample of convenience of therapists, researchers, colleagues, friends and relatives (aged 14-45; Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006). |
Standard Deviation
| Sample | Mean | Comments |
|---|---|---|
| Clinical | 7.5 | Data was derived from 23 sites (n = 890; aged 16-78), the majority of which were within the NHS, but included one university student counselling service and one staff support service. Data was obtained during pre-treatment or first treatment session (Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006). |
| Normative | 5.9 | Data was derived from three samples: (A) 691 university students (aged 17-43); (B) 55 university students (aged 20-45); (C) 360 from a sample of convenience of therapists, researchers, colleagues, friends and relatives (aged 14-45; Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006). |
Reliability
| Value | Comments |
|---|---|
| 0.91 | Connell et al. (2007) derived the consistency reliability of the general population from 553 respondents living in private households in Great Britain and stratified by NHS region and socio-economic conditions. Additionally, 10761 respondents from a clinical population were drawn from various primary and secondary care services. |
| Description | Score Range | |
|---|---|---|
| Below normative mean | 0 | |
| Normative mean | 9 | |
| 1 SD above normative mean | 16.2 | |
| 2 SD above normative mean | 23.4 | |
| Maximum | 40 |
Severity ranges
Values for the normative mean and standard deviation are derived from three samples: (A) 691 university students (aged 17-43); (B) 55 university students (aged 20-45); (C) 360 from a sample of convenience of therapists, researchers, colleagues, friends and relatives (aged 14-45; Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006).
Reliable change and clinically significant improvement
Wampold et al (2001) conducted a meta analysis of psychotherapy outcome studies and noted that the average improvement was reflected in an effect size (ES) of .80. Because a change of 1 SD corresponds to an ES of 1.0, and .80 is considered to be a large ES, Wise (2004) concludes that a change of 1 SD is a defensible indicator of clinically significant change.
Mean
| Sample | Mean | Comments |
|---|---|---|
| Clinical | 23.1 | Data was derived from 23 sites (n = 890; aged 16-78), the majority of which were within the NHS, but included one university student counselling service and one staff support service. Data was obtained during pre-treatment or first treatment session (Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006). |
| Normative | 9 | Data was derived from three samples: (A) 691 university students (aged 17-43); (B) 55 university students (aged 20-45); (C) 360 from a sample of convenience of therapists, researchers, colleagues, friends and relatives (aged 14-45; Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006). |
Standard Deviation
| Sample | Mean | Comments |
|---|---|---|
| Clinical | 8.8 | Data was derived from 23 sites (n = 890; aged 16-78), the majority of which were within the NHS, but included one university student counselling service and one staff support service. Data was obtained during pre-treatment or first treatment session (Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006). |
| Normative | 7.2 | Data was derived from three samples: (A) 691 university students (aged 17-43); (B) 55 university students (aged 20-45); (C) 360 from a sample of convenience of therapists, researchers, colleagues, friends and relatives (aged 14-45; Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006). |
Reliability
| Value | Comments |
|---|---|
| 0.88 | Internal consistency reliability of the clinical sample is noted. Non-clinical sample reliability is 0.90 (Evans et al., 2002). |
Instrument developers
- 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.
Refrences
* Evans, C., Connell, J., Barkham, M., Margison, F., McGrath, G., Mellor-Clark, J., & Audin, K. (2002). Towards a standardised brief outcome measure: Psychometric properties and utility of the CORE–OM. The British Journal of Psychiatry, 180(1), 51-60. * Dogmanas, D., Arias, M. A., Gago, F., de Álava, L., & Roussos, A. (2022). Implementation of a psychological treatment outcomes evaluation system for young people at Uruguay's National Health System: Using CORE‐OM. Counselling and Psychotherapy Research, 22(4), 946-957. * Barkham, M., Mellor-Clark, J., Connell, J., & Cahill, J. (2006). A core approach to practice-based evidence: A brief history of the origins and applications of the CORE-OM and CORE System. Counselling and Psychotherapy Research, 6(1), 3-15. * Barkham, M., Mellor-Clark, J., & Stiles, W. B. (2015). A CORE approach to progress monitoring and feedback: Enhancing evidence and improving practice. Psychotherapy, 52(4), 402. * Twigg, E., Barkham, M., Bewick, B. M., Mulhern, B., Connell, J., & Cooper, M. (2009). The young person's CORE: Development of a brief outcome measure for young people. Counselling and Psychotherapy Research, 9, 160–168. https://doi.org/10.1080/14733140902979722
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Severity ranges
Values for the normative mean and standard deviation are derived from three samples: (A) 691 university students (aged 17-43); (B) 55 university students (aged 20-45); (C) 360 from a sample of convenience of therapists, researchers, colleagues, friends and relatives (aged 14-45; Evans et al., 2002). Mean scores have been multiplied by 10, so that clinically meaningful differences are expressed in whole numbers. Thus, scores range from 0 to 40 (Leach et al., 2006).
Reliable change and clinically significant improvement
Wampold et al (2001) conducted a meta analysis of psychotherapy outcome studies and noted that the average improvement was reflected in an effect size (ES) of .80. Because a change of 1 SD corresponds to an ES of 1.0, and .80 is considered to be a large ES, Wise (2004) concludes that a change of 1 SD is a defensible indicator of clinically significant change.
Mean
Standard Deviation
Reliability