Current research in psychotherapy often focuses on measuring the changes clients experience during therapy. The most common methods used to do this are so-called indirect (pre-post) measures that compare clients' pre- and post-therapy outcomes. However, this approach can be problematic, for example if initial measurements are not available. For this reason, an alternative approach is emerging that attempts to measure change in psychotherapy directly through retrospective assessment of clients, i.e., through a single direct measurement. A new study, involving members of INPSY/Center for Psychotherapy Research, explores the suitability of this approach by psychometrically validating the Czech version of the Questionnaire of Personal Change (Q-PC), which directly captures client-perceived change following psychotherapy.
The study was co-authored by our members Tomáš Řiháček and Hynek Cígler and Kateřina Macková, a current Master's student in psychology at the Faculty of Social Studies. The authors decided to evaluate whether the Czech version of the Q-PC is a suitable tool for direct measurement of change in psychotherapy. The study included two groups of participants: a clinical sample of group therapy clients (N = 222) and a non-clinical control sample (N = 167). The clinical clients were given the Q-PC questionnaire six and twelve months after the end of therapy, while the non-clinical group completed the questionnaire once.
A reliable tool, but with a catch: the phenomenon of positive change bias
The authors found that the Q-PC has good validity and reliability in its Czech version, with the questionnaire showing a consistent unidimensional structure over time. In practice, this means that such a structure reflects well the changes that clients themselves perceive after therapy, and also allows comparison of the magnitude of change between different post-therapy periods. The results of the questionnaire were also comparable to more commonly used indirect measures of change. At the same time, the Q-PC method was found to have excellent sensitivity to change compared to other measurement tools of therapy change. That is, the Q-PC was able to more reliably classify clients who experienced change after therapy than indirect measurement tools.
The authors further hypothesized that the phenomenon of positive change bias could occur with direct retrospective measurement. That is, when reflecting retrospectively on changes after psychotherapy, clients may tend to report positive changes even when none occurred. Research on a non-clinical sample supported this hypothesis, as people who on average were not expected to change reported a small degree of positive change when using Q-PC. The authors suggest possible explanations related to, for example, social desirability, but say replication studies are needed to confirm this effect. Nevertheless, the results serve as a preliminary exploration of this effect and its potential impact on retrospective measures of change.
In conclusion, the authors recommend further research to validate the applicability of Q-PC in different therapeutic and cultural contexts, as well as the long-term stability of the measurement. However, the Q-PC appears to be a valid and reliable tool for measuring change also in the Czech setting. Thus, it may serve to complement traditional indirect measures of change, especially in situations where retrospective measurement could provide a more accurate view of clients' perceptions of progress.
Translated with DeepL.com (free version)
Recommended citation:
Řiháček, T., Macková, K., & Cígler, H. (2024). Direct retrospective measurement of therapeutic changes: an example using the Czech version of the Questionnaire of Personal Changes (Q-PC). Psychotherapy Research, 1–14. https://doi.org/10.1080/10503307.2024.2370357
