The Working Alliance Inventory's Measurement Properties: A Systematic Review

Area of Science:

• Psychometrics
• Healthcare Research
• Systematic Reviews

Background:

• The Working Alliance Inventory (WAI) is widely used in psychotherapy and healthcare, but its measurement properties have not been systematically reviewed.
• Over 30 years of research exist on WAI measurement properties, necessitating a comprehensive analysis.
• The COSMIN (Consensus-based Standards for the selection of health Measurements INstruments) criteria provide a framework for high-quality systematic reviews of measurement properties.

Approach:

• A systematic review was conducted using COSMIN criteria to evaluate studies on the WAI's measurement properties in psychotherapy and other healthcare contexts.
• Databases (PsycINFO, Medline, EMBASE) were searched for studies published between 1989 and 2021.
• 66 studies were included, with rigorous assessment of validity, reliability, and responsiveness, resolving reviewer disagreements through discussion.

Key Points:

• Most studies showed insufficient, lacking, or conflicting evidence for WAI measurement properties based on COSMIN criteria.
• Content validity is unknown due to lack of patient/professional involvement; structural validity and internal consistency evidence is conflicting or absent.
• Limited evidence exists for inter-rater reliability, convergent validity, test-retest reliability, and divergent validity.

Conclusions:

• The Working Alliance Inventory's measurement properties may not meet current standards, or COSMIN criteria may require adaptation for WAI assessment.
• WAI outcomes should be interpreted cautiously, highlighting the need for further research on content validity and hypothesis testing.
• Future research must address the theoretical framework of working alliance measurement in diverse healthcare settings using methodologically sound studies.