Reliability and Validity of an Observational Measure of Client Decision-Making: The Client Language Assessment - Proximal/Distal (CLA-PD)

•The Client Language Assessment – Proximal/Distal (CLA-PD) is a communication rating system for measuring client decision-making in interventions that target a specified behavior change.•Interrater agreement reliability for the CLA-PD was “excellent”.•Internal consistency reliability for the CLA-PD was “fair” to “moderate”.•Convergent and discriminant construct validity analyses showed a pattern of correlations with Motivational Interviewing Skill Code-based ratings (Karno, Longabaugh, & Herbeck, 2010) that were consistent with expectations.•Predictive validity was generally very good, but contrary to expectations, Proximal Change Talk within sessions did not predict subsequent Alcohol Abstinence Self-Efficacy at 3months.•When behavior change treatments are multi-session and/or skill-based, the present analyses suggest the CLA-PD is a psychometrically promising observational rating measure of client verbalized decision-making (i.e., the balance of pro- and anti-change statements).