Reliable Change Index & Caseness Threshold
In This Article
Reliable Change Index (RCI)
Reliable change is a concept used in mental health research to determine whether an individual's change in symptoms or functioning over time is a genuine change or merely a result of measurement error. In other words, reliable change takes into account the possibility that an individual's scores on mental health assessments can fluctuate due to random factors or measurement error, rather than actual changes in their mental health status. This can help ensure that individuals receive appropriate treatment based on their actual mental health status, rather than just temporary fluctuations in their scores on assessments.
Researchers use statistical methods to compare the individual's scores on mental health assessments at different points in time. If the change in scores is statistically significant and exceeds a certain threshold, it is considered a reliable change. Research studies often use reliable change as a criterion for determining the effectiveness of mental health treatments. For example, if a group of individuals with depression receives a treatment, and a statistically significant number of them show reliable change in their symptoms, it suggests that the treatment may be effective for treating depression.
Caseness Threshold
Greenspace evaluates recovery using the concept of ‘caseness,’ which indicates that a patient’s symptoms are severe enough to be classified as a clinical case. A referral is considered to have achieved recovery if the patient was classified as a clinical case at the beginning of treatment (based on their baseline assessment score) and is no longer classified as such at the end of treatment (based on the most recent assessment score). This determination is made using scores from questionnaires designed for their specific condition.
Definitions
Reliable deterioration: a deterioration in score that is greater than the reliable change threshold for this measure.
Reliable recovery: an improvement in score that is greater than the reliable change threshold for this measure and in which the first assessment score was above the caseness threshold while the last score is below the caseness threshold.
Reliable improvement: an improvement in score that is greater than the reliable change threshold for this measure.
Clinically significant change: a change in score that meets or exceeds the reliable change threshold for this measure.
Assessments Available
Greenspace uses published and verified values for Reliable Change and Caseness. This does mean that not all assessments have a RCI and/or caseness attached to them.
Below are the Caseness and Reliable Change Index (RCI) cutoffs that Greenspace uses:
| Assessment | Code | Caseness | RCI | Source |
|---|---|---|---|---|
| Generalised Anxiety Disorder – 7 | GAD-7 | ≥8 | ≥4 | IAPT |
| Health Anxiety Inventory | HAI | ≥18 | ≥4 | IAPT |
| Obsessive-Compulsive Inventory | OCI | ≥40 | ≥32 | IAPT |
| Panic Disorder Severity Scale | PDSS | ≥8 | ≥5 | IAPT |
| Patient Health Questionnaire -9 | PHQ-9 | ≥10 | ≥6 | IAPT |
| Patient Health Questionnaire – 15 | PHQ-15 | ≥10 | ≥7 | IAPT |
| PTSD Checklist for DSM-5 | PCL-5 | ≥32 | ≥10 | IAPT |
| Social Phobia Inventory | SPIN | ≥19 | ≥10 | IAPT |
| Pediatric Symptom Checklist | PSC-17 | ≥15 | ≥6 | Murphy et al. |
| Anxiety | OASIS | ≥8 | ≥5 | Campbell-Sills et al. |
| Work and Social Functioning | WSAS | ≥10 | - | Mundt, Marks et al. |
Resources
- Evans, C., Margison, F. & Barkham, M. (1998). The contribution of reliable and clinically significant change methods to evidence-based mental health. Evidence Based Mental Health, 1:70-72.
- Jacobson, N. S., Follette, W. C. & Revenstorf, D. (1984). Psychotherapy outcome research: methods for reporting variability and evaluating clinical significance. Behavior Therapy, 15: 336-352.
- Jacobson, N. S. & Truax, P. (1991). Clinical significance: a statistical approach to defining meaningful change in psychotherapy research. Journal of Consulting and Clinical Psychology, 59(1): 12-19.
- Christensen, L. & Mendoza, J. L. (1986). A method of assessing change in a single subject: an alteration of the RC index. Behavior Therapy, 17: 305-308.
- Gudmundsson, E., & Bøgwald, K. P. (2016). Validity of clinically significant change classifications yielded by Jacobson-Truax and Hageman-Arrindell methods. BMC psychiatry, 16(1), 329. https://doi.org/10.1186/s12888-016-0895-5
- Psychotherapy and Counselling Union (2016). Reliable and clinically significant change. Retrieved May 3, 2023, from https://www.psyctc.org/stats/rcsc.htm