Background: Despite the importance of assessing the quality with which low-intensity (LI) group psychoeducational interventions are delivered, no measure of treatment integrity (TI) has been developed.
Aims: To develop a psychometrically robust TI measure for LI psychoeducational group interventions.
Method: This study had two phases. Firstly, the group psychoeducation treatment integrity measure-expert rater (GPTIM-ER) and a detailed scoring manual were developed. This was piloted by n=5 expert raters rating the same LI group session; n=6 expert raters then assessed content validity. Secondly, 10 group psychoeducational sessions drawn from routine practice were then rated by n=8 expert raters using the GPTIM-ER; n=9 patients also rated the quality of the group sessions using a sister version (i.e. GPTIM-P) and clinical and service outcome data were drawn from the LI groups assessed.
Results: The GPTIM-ER had excellent internal reliability, good test-retest reliability, but poor inter-rater reliability. The GPTIM-ER had excellent content validity, construct validity, formed a single factor scale and had reasonable predictive validity.
Conclusions: The GPTIM-ER has promising, but not complete, psychometric properties. The low inter-rater reliability scores between expert raters are the main ongoing concern and so further development and testing is required in future well-constructed studies.
Keywords: Adherence; Competence; Group therapy; Improving Access to Psychological Therapies Programme (IAPT); Psychoeducation.