Multimodal Assessments of Therapist Characteristics Are Largely Unrelated to Patient Outcomes: A Preregistered Analysis

Although it is known that therapists vary in effectiveness, it is unclear what therapist-level characteristics predict this variation. We conducted a large-scale preregistered study ( N = 97 therapists from the United States and Canada, N = 6,152 patients) examining a multimodal set of 38 therapist-level predictors that have been empirically or theoretically linked with patient outcomes. We examined associations with pre-post change and rate of change in psychological distress and likelihood of attending more than one treatment session. We largely did not find associations between therapist-level characteristics and patient outcomes. Most predictors failed to replicate across sensitivity analyses and/or were nonsignificant following p -value correction. The most robust evidence suggested that interpersonal capacities assessed via a performance task are associated with likelihood of attending more than one treatment session. A key limitation of the study is small therapist effects that may have reduced statistical power. Empirically, it remains uncertain what qualities characterize highly effective therapists.