Validation of the Rasch-based Depression Screening in a large scale German general population sample

Area of Science:

• Psychometrics
• Clinical Psychology
• Mental Health Assessment

Background:

• The Rasch-based Depression Screening (DESC) is a tool for assessing depression.
• Normative data and psychometric properties of the DESC needed evaluation in a general population.

Purpose of the Study:

• To present normative data for both parallel forms of the "Rasch-based Depression Screening (DESC)".
• To examine the DESC's Rasch model conformity.
• To assess the DESC's convergent and divergent validity.

Main Methods:

• A representative sample of the German general population (N = 2509) was used.
• Rasch model assumptions (fit, unidimensionality, local independence, DIF) were analyzed.
• Convergent and divergent validity was assessed using the Hospital Anxiety and Depression Scale (HADS).

Main Results:

• The DESC adhered to Rasch model assumptions with good fit statistics and no DIF.
• Unidimensionality and local independence were supported by principal component factor analysis of residuals (PCFAR).
• Correlations with HADS subscales indicated good convergent and divergent validity.

Conclusions:

• The DESC demonstrates strong psychometric quality and adherence to Rasch model assumptions.
• The normative data enhance the DESC's utility for clinical and research applications.
• The DESC is a valid and reliable tool for depression screening in the general population.