The Harvard Trauma Questionnaire: Reliability and Validity Generalization Studies of the Symptom Scales

Title: The Harvard Trauma Questionnaire: Reliability and Validity Generalization Studies of the Symptom Scales
Authors: Darzi, Chantal
Date: 2017
Abstract: The cross-cultural applicability of the PTSD diagnosis has been widely disputed in recent years. Consequently, an examination of the psychometric properties of instruments that are used to assess traumatized individuals of various cultures is of utmost importance. To respond to this need, the overall goal of this dissertation was to evaluate the psychometric properties of the Harvard Trauma Questionnaire (HTQ; Mollica et al., 1992), a measure that was developed to assess trauma symptoms across cultures. In the first study, I conducted a search of all publications and dissertations that used the symptoms scales of the HTQ. This search revealed that the HTQ is commonly used by trauma researchers, however only a minority of them reported using established translation and cultural adaptation procedures to adapt the instrument for their specific sample. In addition, of the 384 studies considered for inclusion, only 44% of them reported internal consistency estimates of their sample. I then performed reliability generalization analyses on Cronbach’s alpha coefficients to assess the reliability properties of the HTQ symptom scales. Overall, 103 samples were included in the analyses, representing various cultures, languages and countries of study. The findings of this study indicated that both the HTQ-16 and 30 symptom scales are likely to provide reliable scores across diverse populations. However, the evidence supporting the reliability of scores produced for the re-experiencing, avoidance/numbing and arousal subscales is less strong. Significant moderating effects were found for various sample and methodological variables, such as the gender composition of the sample, cultural group, cultural orientation of the country of origin and trauma type. Building upon the findings of study 1, I performed validity generalization (VG) analyses to assess the overall construct validity of the HTQ symptom scales in Study 2. Seventy-five independent samples were included in the VG that evaluated the convergent and discriminant validity properties of both the HTQ-16 and HTQ-30. The findings revealed that the convergent validity properties of the HTQ-16 are supported to some extent, but the discriminant validity properties are not. Furthermore, there was limited support for either the convergent or discriminant validity of the HTQ-30. Several significant moderating effects were also found for both scales (i.e. age, gender, cultural group, recruitment site, trauma type, being an original sample). Although these studies shed some light into the overall psychometric strength of the HTQ symptom scales, the decision whether to use this instrument for the assessment of PTSD should also be guided by evidence-based assessment guidelines.
CollectionThèses, 2011 - // Theses, 2011 -