Development and validation of an 8-item version of the Real Relationship Inventory-Client form.

Area of Science:

• Psychology
• Clinical Psychology
• Psychotherapy Research

Background:

• The therapeutic relationship is crucial for treatment outcomes.
• Existing measures, like the 24-item Real Relationship Inventory-Client (RRI-C), can be lengthy for clinical practice.
• A shorter, validated instrument is needed to efficiently assess key components of the therapeutic alliance.

Purpose of the Study:

• To develop and validate a brief, 8-item version of the Real Relationship Inventory-Client (RRI-C-SF).
• To ensure the shortened scale retains the psychometric properties of the original RRI-C.
• To confirm the RRI-C-SF's reliability and validity for use in diverse therapeutic contexts.

Main Methods:

• Utilized two independent samples of psychotherapy patients (N1=700, N2=434) for scale development and validation.
• Employed psychometric scale shortening techniques including exploratory and confirmatory factor analysis (CFA), and item response theory.
• Assessed reliability, convergent validity, discriminant validity, and measurement invariance across in-person and remote sessions.

Main Results:

• The 8-item RRI-C-SF successfully preserved the two-factor structure of Genuineness and Realism.
• Confirmatory factor analysis (CFA) indicated excellent model fit (X²/df=2.16, CFI=.99, TLI=.96, RMSEA=.07, SRMR=.03).
• The RRI-C-SF demonstrated high reliability (α=.91), strong correlation with the full scale (r=.96), and robust validity, proving invariant across session formats.

Conclusions:

• The RRI-C-SF is a psychometrically sound and reliable instrument for assessing the real relationship in psychotherapy.
• This brief scale facilitates efficient assessment of genuineness and realism, supporting both research and clinical applications.
• The validated RRI-C-SF provides valuable benchmarks for evaluating therapeutic alliance and treatment progress.