Development and initial evaluation of a treatment integrity measure for low-intensity group psychoeducational interventions.

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.