A Rasch-based validity study of the Harvard Trauma Questionnaire.

Area of Science:

• Psychiatry
• Psychometrics
• Refugee Health

Background:

• The Harvard Trauma Questionnaire (HTQ) is widely used for assessing Posttraumatic Stress Disorder (PTSD) in refugees.
• Its use for measuring treatment outcomes requires specific validation, which has been lacking.
• This study addresses this gap by validating the HTQ using the Rasch model.

Purpose of the Study:

• To validate the Harvard Trauma Questionnaire (HTQ) for assessing treatment outcomes in refugees with PTSD.
• To evaluate the psychometric properties of the HTQ using Rasch analysis.
• To identify reliable subscales for summarizing HTQ responses.

Main Methods:

• Rasch model analysis was applied to data from 641 Arabic and Persian speaking refugees diagnosed with PTSD.
• The analysis tested assumptions of unidimensionality, local independence, and absence of differential item functioning.
• Responses were evaluated against Rasch model criteria.

Main Results:

• Two subscales, arousal/intrusion and avoidance/numbing, met Rasch model criteria when accounting for local dependence and differential item functioning.
• These subscales demonstrated acceptable psychometric properties within the study sample.
• The findings suggest a potential for optimized scoring of the HTQ.

Conclusions:

• The arousal/intrusion and avoidance/numbing subscales are recommended for summarizing HTQ responses in PTSD-affected refugees.
• These subscales offer an optimized and valid method for assessing treatment outcomes.
• The HTQ, with these validated subscales, remains a simple yet effective tool for summarizing patient scores.