Ruminative response scale for eating disorders: bifactor model and measurement invariance in a Portuguese community...

Area of Science:

• Psychology
• Clinical Psychology
• Psychometrics

Background:

• Rumination is a cognitive process linked to eating psychopathology.
• The Ruminative Response Scale for Eating Disorders (RRS-ED) assesses eating disorder-specific rumination.
• Understanding the RRS-ED's structure in diverse populations is crucial.

Purpose of the Study:

• To examine the factor structure of the RRS-ED in a Portuguese community sample.
• To test the invariance of the RRS-ED factor structure across sex.
• To evaluate the RRS-ED's validity and reliability in a non-clinical population.

Main Methods:

• A sample of 535 Portuguese adults (179 male, 356 female) completed the RRS-ED.
• A subsample (n=347) completed measures of repetitive negative thinking and eating psychopathology.
• Confirmatory factor analysis utilized correlated two-factor, unifactorial, and bifactor models.

Main Results:

• The bifactor model demonstrated the best fit for the RRS-ED, indicating a reliable general rumination factor.
• The bifactor model of the RRS-ED was found to be invariant across sex.
• RRS-ED scores correlated moderately to strongly with negative perseverative thinking and eating psychopathology.

Conclusions:

• The RRS-ED is a reliable and valid measure for assessing rumination in the Portuguese general population.
• Evidence supports using the RRS-ED total score as an overall measure of rumination.
• Domain-specific factor scores should be interpreted with caution; further research is needed to confirm unidimensionality.