Direct retrospective measurement of therapeutic changes: An example using the Czech version of the Questionnaire of...

Objective: The study aimed to test the psychometric properties of the Czech translation of the Questionnaire of Personal Changes (Q-PC), a measure designed for retrospective (direct) measurement of change in psychotherapy.Methods: A sample of group psychotherapy clients (N = 222) and a nonclinical sample (N = 167) sample were used. Clients in the clinical sample were administered the Q-PC in addition to several pre-post outcome measures. Confirmatory factor analysis, correlational analysis, and structural equation modeling were used to test the Q-PC's factor structure, longitudinal measurement invariance, reliability, convergent validity, sensitivity to change, and other psychometric properties.Results: The Q-PC demonstrated a unidimensional structure that was strictly invariant between two follow-up measurement waves. The measure also demonstrated excellent reliability and sensitivity to change and good convergent validity. Furthermore, it demonstrated a similar relationship to baseline severity as the pre-post outcome measures.Conclusions: The retrospective measurement of change is a promising approach that has the potential to complement the traditional pre-post measurement of change.