Bi-factor Exploratory Structural Equation Modeling Done Right: Using the SLiDapp Application.

BACKGROUND: Due to its flexibility and statistical properties, bi-factor Exploratory Structural Equation Modeling (bi-factor ESEM) has become an often-recommended tool in psychometrics. Unfortunately, most recent methods for approximating these structures, such as the SLiD algorithm, are not available in the leading software for performing ESEM (i.e., Mplus). To resolve this issue, we present a novel, user-friendly Shiny application for integrating the SLiD algorithm in bi-factor ESEM estimation in Mplus. Thus, a two-stage framework for conducting SLiD-based bi-factor ESEM in Mplus was developed. METHOD: This approach was presented in a step-by-step guide for applied researchers, showing the utility of the developed SLiDApp application. Using data from the Open-Source Psychometrics Project (N = 2495), we conducted a bi-factor ESEM exploration of the Generic Conspiracist Beliefs Scale. We studied whether bi-factor modelling was appropriate and if both general and group factors were related to each personality trait. RESULTS: The application of the SLiD algorithm provided unique information regarding this factor structure and its ESEM structural parameters. CONCLUSIONS: The results illustrated the usefulness and validity of SLiD-based bi-factor ESEM, and how the proposed Shiny app could make it eaiser for applied researchers to use these methods.

Calibrating a new item pool to adaptively assess the Big Five.

BACKGROUND: Even though the Five Factor Model (FFM) has been the dominant paradigm in personality research for the past two decades, very few studies have measured the FFM adaptively. Thus, the purpose of this research was the building of a new item pool to develop a computerized adaptive test (CAT) for personality assessment. METHOD: A pool of 480 items that measured the FFM facets was developed and applied to 826 participants. Facets were calibrated separately and item selection was performed being mindful of the preservation of unidimensionality of each facet. Then, a post-hoc simulation study was carried out to test the performance of separate CATs to measure the facets. RESULTS: The final item pool was composed of 360 items with good psychometric properties. Findings reveal that a CAT administration of four items per facet (total length of 120 items) provides accurate facets scores, while maintaining the factor structure of the FFM. CONCLUSIONS: An item pool with good psychometric properties was obtained and a CAT simulation study demonstrated that the FFM facets could be measured with precision using a third of the items in the pool.

[Infectious bacteremic ecthyma in a patient with HIV infection]. / Ectima infeccioso bacteriémico en paciente con infección por virus de la inmudeficiencia humana.

Ecthyma is a deep ulcerative pyoderma usually caused by group A beta-hemolytic streptococcus (Streptococcus pyogenes). It usually presents in areas of damaged skin and in immunocompromised patients, and very infrequently is accompanied by general symptoms and bacteremia. We describe the case of a 41-year-old female patient with HIV infection who presented with fever and ulcerated lesions on the right ankle and left foot which had been developing for three weeks. Streptococcus pyogenes and Escherichia coli were simultaneously isolated from a culture of the skin biopsy sample and from blood cultures. Escherichia coli is of dubious pathogenic significance in this case.