Structural Validity of the World Assumption Scale.

The World Assumption Scale (WAS) is a frequently used measure in trauma research. The 32 items of the WAS are intended to represent eight assumptions about the benevolence of the world, the meaningfulness of events, and the worthiness of the self. Debate about the validity of the WAS is ongoing, particularly in terms of its empirical factor structure; some studies have confirmed a model of eight correlated factors whereas several other studies have not. The WAS items were administered to a clinical sample of patients who sought professional help because of posttraumatic complaints (n = 1,791) as well as a sample of healthcare professionals (n = 236). We split the clinical sample into three subsamples, then performed exploratory factor analysis using data from one subsample and tested the factor structure with confirmatory factor analysis using the other two subsamples. A consistent model of eight correlated factors was demonstrated, with almost all factors showing acceptable reliability, Cronbach's αs = .68-.84. We tested this factor model against data from the sample of healthcare professionals with increasingly stringent levels of invariance and found it to be scalar invariant (same structure, loadings, and thresholds). In a regression analysis, five factors showed significant associations with posttraumatic stress disorder (PTSD) symptoms, and two factors had unique associations with PTSD symptoms after we controlled for traumatic events: Self-Worth, ß = -.31; and Luck, ß = -.15. Future research should aim to distinguish between different assumptions and their individual influences on posttraumatic complaints.

The Existential Concerns Questionnaire (ECQ)-Development and Initial Validation of a New Existential Anxiety Scale in a Nonclinical and Clinical Sample.

OBJECTIVE: Existential anxiety (EA) is a construct that refers to fears that are provoked by core threats of human existence, such as death, meaninglessness, and fundamental loneliness. The objective of this study was to develop an EA measure that can be used in research and clinical practice. METHOD: The Existential Concerns Questionnaire (ECQ) was completed by a nonclinical sample of 389 adults, together with questionnaires measuring death anxiety, intolerance of uncertainty, neuroticism, distress, meaning, and life events. Adaptations were made based on item analysis and factor analysis. A total of 99 adults who had an anxiety and/or depressive disorder completed the final version. RESULTS: The ECQ was demonstrated to be essentially unidimensional and showed good reliability and stability. Correlations with other measures were within the expected range of strength, except for a weak association with life events. CONCLUSION: Initial results regarding the psychometric properties of the ECQ are promising.

Improving the analysis of routine outcome measurement data: what a Bayesian approach can do for you.

Since recent decades, clinicians offering interventions against mental problems must systematically collect data on how clients change over time. Since these data typically contain measurement error, statistical tests have been developed which should disentangle true changes from random error. These statistical tests can be subdivided into two types: classical tests and Bayesian tests. Over the past, there has been much confusion among analysts regarding the questions that are answered by each of these tests. In this paper we discuss each type of test in detail and explain which questions are, and which are not, answered by each of the types of tests. We then apply a test of each type on an empirical data set and compare the results. Copyright © 2015 John Wiley & Sons, Ltd.

An evaluation of the Brief Symptom Inventory-18 using item response theory: which items are most strongly related to psychological distress?

The psychometric structure of the Brief Symptom Inventory-18 (BSI-18; Derogatis, 2001) was investigated using Mokken scaling and parametric item response theory. Data of 487 outpatients, 266 students, and 207 prisoners were analyzed. Results of the Mokken analysis indicated that the BSI-18 formed a strong Mokken scale for outpatients and prisoners, indicating strong unidimensionality. For students, only the depression and anxiety items formed a medium Mokken scale. Parametric item response theory analyses showed that the best discriminating items came from the depression and anxiety subscales.