A baseline comparison of three diagnostic groups using the Progress Monitoring Tool for Eating Disorders

Area of Science:

• Psychiatry
• Clinical Psychology
• Psychometrics

Background:

• Intensive inpatient treatment for eating disorders (EDs) is increasing, highlighting the need for validated progress monitoring tools.
• The Progress Monitoring Tool for Eating Disorders (PMED) was developed for inpatient ED settings.
• Previous studies support the PMED's factorial validity and internal consistency.

Purpose of the Study:

• To test the measurement invariance of the PMED across anorexia nervosa subtypes (restricting and binge-purge) and bulimia nervosa.
• To evaluate the PMED's appropriateness for complex eating disorder patient populations in inpatient care.

Main Methods:

• Measurement invariance (MI) testing was employed using progressively constrained models.
• The study included 1121 female patients diagnosed with anorexia nervosa-restricting type, anorexia nervosa-binge-purge type, or bulimia nervosa.
• Analysis focused on configural, metric, and scalar invariance of the PMED.

Main Results:

• The PMED demonstrated configural and metric measurement invariance across the three diagnostic groups.
• Scalar invariance was not achieved, indicating that PMED scores may reflect different levels of psychopathology across diagnostic groups.
• The PMED appears suitable for assessing baseline functioning in inpatient ED populations.

Conclusions:

• The PMED functions consistently in assessing constructs and items across anorexia nervosa and bulimia nervosa subtypes in inpatient settings.
• Comparisons of symptom severity between different ED diagnoses using the PMED should be made with caution.
• The PMED is a reliable tool for understanding initial patient functioning in specialized inpatient ED treatment.