The Contribution of Common Factors to Therapeutic Outcomes from the Clinician's Perspective: A Mixed Method Study to Explore Common Mechanisms of Change

While the Common Factors (CFs) model is becoming more popular it has been criticized for the lack of empirical evidence compared to empirically supported treatments and the lack of capacity to guide clinicians on what to do and when to do it in the course of therapy. This parallel mixed methods study addressed both of these critiques. In phase one, a Common Factors Questionnaire (Karimi-CFQ) was developed to collect empirical data of CFs. In phase two, the Karimi-CFQ was administered to 391 clinicians in the United States to survey the therapists' perspective regarding the contribution of common factors to therapy outcomes. In this phase data was also collected to assess the relationship between clinicians' demographic characteristics and their perceived contribution of common factors to therapeutic change. The CFQ Cronbach's Alpha and Split-half reliability were .84 and .87, respectively. Content Validity Index by expert panel, concurrent validity, and construct validity including Exploratory Factors Analysis (EFA) and Confirmatory Factor Analysis (CFA, χ²=797.96, df=326; RMSEA=.06; CFI=.83) evaluated the validity of the scale. Clinicians across five clinical orientations (Integrative, Cognitive Behavior Therapy, Humanistic, Psychodynamic, Postmodern) and three mental health disciplines (marriage and family therapy, psychology, counseling) attributed 69% of therapeutic change to common factors versus 31% to model-specific factors. Clinicians attributed different contributions to specific components of the CFs model: client (25%), therapist (20%), relationship (23%), hope (12%), non-theory specific (11%), and systemic (9%). Particular clinicians' characteristics (e.g., gender, year of experience) were found to be associated with contributions of specific components of CFs. In phase three, six CF experts were invited to respond to open-ended questions via Wiki that explored how and when experienced therapists use specific common factors in the course of therapy to reach to their therapy goals. Thematic Analysis (TA) generated a chronological map with specific themes that can guide clinicians on how and when specific CFs can be used in each of the three stages of therapy (i.e. Initial, Intermediate, Termination). Findings further indicated that CFs and model-specific factors can be operationally defined and empirically studied within the same evidence-based practice framework. Clinical and research implications of the results are also discussed.