In plain language
Most psychotherapy research compares whole treatment packages against each other, which tells us little about why people improve. Process-based therapy (PBT) takes a different approach: it focuses on the specific biopsychosocial processes of change that matter for an individual person’s goals. But to do that well, clinicians need brief, flexible measures that can be given repeatedly over time and analysed at the level of the individual — something traditional questionnaire validation methods were never designed to support.
In this study, the authors developed the Process-Based Assessment Tool (PBAT), an item pool created from the Extended-Evolutionary Meta-Model (EEMM) of process-based therapy. Rather than validating a fixed scale, they evaluated each item individually and competitively using a machine-learning algorithm, administering the items online to 598 adults alongside measures of psychological need satisfaction, need thwarting, and clinically relevant outcomes such as sadness, anger, anxiety, stress, social support, vitality, and health.
The resulting 18-item PBAT distinguished positive from negative processes of change, related in theoretically coherent ways to need satisfaction and thwarting, and predicted the clinical outcomes. The authors describe the PBAT as a “tool drawer”: clinicians and researchers can select individual items or subsets suited to a particular person or purpose, opening the way for idionomic (individual-first) research and practice.
Key findings
- An item pool for process-based assessment was developed from the Extended-Evolutionary Meta-Model (EEMM) and evaluated in an online sample of 598 adults (mean age 32.6).
- Items were evaluated individually and competitively using a machine-learning algorithm suited to item-level evaluation, rather than traditional scale-validation methods.
- The final 18-item PBAT reliably distinguished between positive and negative processes of change, supporting the first hypothesis.
- PBAT items linked in theoretically coherent ways to established measures of psychological need satisfaction and need thwarting.
- Every retained item related to clinically relevant outcomes, including sadness, anger, anxiety, stress, lack of social support, vitality, and health.
- The two cognition items (thinking helped; thinking got in the way) were among the top predictors of positive and negative outcomes, consistent with the emphasis of cognitive behavioral therapies.
How to cite
APA
Ciarrochi, J., Sahdra, B., Hofmann, S. G., & Hayes, S. C. (2022). Developing an item pool to assess processes of change in psychological interventions: The Process-Based Assessment Tool (PBAT). Journal of Contextual Behavioral Science, 23, 200–213. https://doi.org/10.1016/j.jcbs.2022.02.001
BibTeX
@article{ciarrochi2022developing,
title = {Developing an item pool to assess processes of change in psychological interventions: The Process-Based Assessment Tool (PBAT)},
author = {Ciarrochi, Joseph and Sahdra, Baljinder and Hofmann, Stefan G. and Hayes, Steven C.},
journal = {Journal of Contextual Behavioral Science},
volume = {23},
pages = {200--213},
year = {2022},
doi = {10.1016/j.jcbs.2022.02.001}
}
Related work
- All publications by Joseph Ciarrochi (searchable, with free PDFs)
- Process-Based Therapy & Idionomic Analysis
- The Process-Based Assessment Tool (free download)
Author: Joseph Ciarrochi (ORCID 0000-0003-0471-8100). Free copy hosted with permission for scholarly use. Please cite the published version via the DOI above.