Assessment of adherence and competence in cognitive therapy: comparing session segments with entire sessions.

The aim of the study was to compare the reliability and validity of adherence and competence judgments of four raters, based on session segments on the one hand and on entire sessions on the other. The global adherence/competence judgments based on the middle section of 34 therapy sessions demonstrated satisfactory interrater reliability (ICC=.81/.71) and the highest correlations with therapy outcome (r=.55/.45). These results were comparable with judgments based on entire therapy sessions. However, the reliability of specific aspects of adherence and competence was higher when judgments were based on the entire session. The implications of these results are important in terms of reducing time and costs associated with the judgment process.