Therapist Competence Measure Development for Comprehensive Behavioral (COMB) Treatment of Trichotillomania (TTM)

Exploratory analysis from the first randomized controlled trial of Comprehensive Behavioral (ComB) Treatment of Trichotillomania (TTM) indicated that treatment outcomes may be influenced by therapist experience: participants treated by therapists with prior TTM treatment experience saw greater improvement in self-rated hair pulling severity than their counterparts treated by therapists with no prior TTM treatment experience (Carlson et al., 2021). The purpose of the current study was to develop an instrument for assessing therapist competence in ComB delivery and perform initial tests on its psychometric properties. The ComB Competence Measure was developed for this study and is made up of 14-items, each dedicated to a specific skill in ComB. Two independent raters used the ComB Competence Measure to rate therapist competency in ComB from sixty randomly selected session recordings from the first ComB RCT (Carlson et al., 2021). Inter-rater reliability of the measure was assessed through two-way mixed model intraclass correlation coefficients with absolute agreement between the two raters and concurrent validity was assessed through difference of mean competence scores between therapists with and without prior TTM treatment experience. The measure received modest reliability support for its composite (average) score. The measure’s concurrent validity was supported, as the more experienced therapists had a significantly higher composite score compared to less experienced therapists. Refinement of the ComB competence measure would provide the means for researchers to further investigate therapist effects on treatment outcomes, facilitate study comparisons, and quality control for therapist inclusion into research studies.