Moderators in psychotherapy meta-analysis.

Area of Science:

• Psychology
• Psychotherapy Research
• Meta-analysis Methodology

Background:

• Psychotherapy meta-analyses frequently yield heterogeneous results.
• Methodological variations across studies, such as control condition differences, contribute to this heterogeneity.
• Understanding these variations is crucial for interpreting findings and improving future research.

Purpose of the Study:

• To provide an overview of key moderator variables relevant to psychotherapy trials.
• To identify moderators that can explain heterogeneous results within and between psychotherapy meta-analyses.
• To encourage the incorporation of these moderators in future meta-analytic studies.

Main Methods:

• Review of moderator variables applicable to psychotherapy research.
• Analysis of 15 psychotherapy meta-analyses published in 2016.
• Categorization of moderators into structural equivalence, preferences/allegiances, therapist effects, and sample representativeness.

Main Results:

• Structural equivalence of conditions, patient/therapist preferences, therapist effects, nested data, and sample representativeness are often overlooked moderators.
• These factors significantly influence the generalizability of psychotherapy effects.
• Conceptual and methodological challenges in moderator analysis, like treatment categorization and interrater coding, were identified.

Conclusions:

• Relevant moderator variables are essential for explaining heterogeneity in psychotherapy meta-analyses.
• These moderators are frequently neglected and should be systematically incorporated into future meta-analyses.
• Addressing these methodological aspects will enhance the validity and interpretability of psychotherapy research.