Adherence Rating Scale for Cognitive Processing Therapy - Cognitive Only: Analysis of Psychometric Properties.

BACKGROUND

The assessment of therapeutic adherence is essential for accurately interpreting treatment outcomes in psychotherapy research. However, such assessments are often neglected.

AIMS

To fill this gap, we aimed to develop and test a scale that assessed therapeutic adherence to Cognitive Processing Therapy - Cognitive Only (CPT), which was adapted for a treatment study targeting patients with post-traumatic stress disorder and co-occurring borderline personality symptoms.

METHOD

Two independent, trained raters assessed 30 randomly selected treatment sessions involving seven therapists and eight patients who were treated in a multicentre randomized controlled trial.

RESULTS

The inter-rater reliability for all items and the total score yielded good to excellent results (intraclass correlation coefficient [ICC] = 0.70 to 1.00). Cronbach's α was .56 for the adherence scale. Regarding content validity, three experts confirmed the relevance and appropriateness of each item.

CONCLUSION

The adherence rating scale for the adapted version of CPT is a reliable instrument that can be helpful for interpreting treatment effects, analysing possible relationships between therapeutic adherence and treatment outcomes and teaching therapeutic skills.