RESUMO
Background: The introduction of the diagnosis of complex posttraumatic stress disorder (CPTSD) by ICD-11 is a turning point in the field of traumatic stress studies. It's therefore important to examine the validity of CPTSD in refugee groups exposed to complex trauma (CT) defined as a repeated, prolonged, interpersonal traumatic event. Objective: The objective of this study was to compare DSM-5 and ICD-11 post-traumatic stress disorder diagnoses and to evaluate the discriminant validity of ICD-11 PTSD and CPTSD constructs in a sample of treatment-seeking refugees living in Italy. Method: The study sample included 120 treatment-seeking African refugees living in Italy. All participants were survivors of at least one CT. PTSD and CPTSD diagnoses were assessed according to both DSM-5 and ICD-11 criteria. Results: Findings revealed that 79% of the participants met the DSM-5 criteria for PTSD, 38% for ICD-11 PTSD and 30% for ICD-11 CPTSD. Generally, ICD-11 CPTSD items evidenced strong sensitivity and negative predictive power, low specificity and positive predictive power. Latent class analysis results identified two distinct groups: (1) a PTSD class, (2) a CPTSD class. None of the demographic and trauma-related variables analysed was significantly associated with diagnostic group. On the other hand, the months spent in Italy were significantly associated with PCL-5 score. Conclusions: Findings extend the current evidence base to support the discriminant validity of PTSD and CPTSD amongst refugees exposed to torture and other gross violations of human rights. The results suggest also that, in the post-traumatic phase, the time spent in a 'safe place' condition contributes to improve the severity of post-traumatic symptomatology, but neither this variable nor other socio-demographic factors seem to contribute to the emergence of complex PTSD. Further investigations are needed to clarify which specific vulnerability factors influence the development of PTSD or CPTSD in refugees exposed to complex trauma.
Antecedentes: La introducción del diagnóstico del trastorno de estrés postraumático complejo (TEPT-C) por la CIE-11 es un punto de inflexión en el campo de los estudios del estrés traumático. Por lo tanto, es importante examinar la validez del TEPT-C en los grupos de refugiados expuestos a un trauma complejo (TC) definido como un evento traumático interpersonal prolongado y repetido.Objetivo: El objetivo de este estudio fue comparar los diagnósticos de trastorno de estrés postraumático del DSM-5 y la CIE-11 y evaluar la validez discriminante de los constructos del TEPT y TEPT-C de la CIE-11 en una muestra de refugiados en busca de tratamiento que viven en Italia.Método: La muestra del estudio incluyó a 120 refugiados africanos que buscan tratamiento y que viven en Italia. Todos los participantes fueron sobrevivientes de al menos un TC. Los diagnósticos de TEPT y TEPT-C se evaluaron de acuerdo con los criterios del DSM-5 y de la CIE-11.Resultados: Los hallazgos muestran que el 79% de los participantes cumplieron con los criterios del DSM-5 para el TEPT, el 38% para el TEPT de la CIE-11 y el 30% para el TEPT-C de la CIE-11. En general, los ítems de TEPT-C de la CIE-11 evidenciaron una fuerte sensibilidad y poder predictivo negativo, baja especificidad y poder predictivo positivo. Los resultados del análisis de clase latente identificaron dos grupos distintos: (1) grupo de TEPT, (2) grupo de TEPT-C. Ninguna de las variables demográficas y relacionadas con el trauma analizadas se asoció significativamente con el grupo de diagnóstico. Por otro lado, los meses pasados en Italia se asociaron significativamente con la puntuación de PCL-5.Conclusiones: Los hallazgos amplían la base de evidencia actual para apoyar la validez discriminante del TEPT y el TEPT-C entre los refugiados expuestos a tortura y otras violaciones graves de los derechos humanos. Los resultados sugieren también que, en la fase postraumática, el tiempo pasado en una condición de "lugar seguro" contribuye a mejorar la gravedad de la sintomatología postraumática, pero ni esta variable ni otros factores sociodemográficos parecen contribuir a la aparición del TEPT-C. Se necesitan más investigaciones para aclarar qué factores de vulnerabilidad específicos influyen en el desarrollo de TEPT o TEPT-C en los refugiados expuestos a trauma complejo.
RESUMO
Hyperspectral data can provide prediction of physical and chemical vegetation properties, but data handling, analysis, and interpretation still limit their use. In this study, different methods for selecting variables were compared for the analysis of on-the-ground hyperspectral signatures of wheat grown under a wide range of nitrogen supplies. Spectral signatures were recorded at the end of stem elongation, booting, and heading stages in 100 georeferenced locations, using a 512-channel portable spectroradiometer operating in the 325-1075-nm range. The following procedures were compared: (i) a heuristic combined approach including lambda-lambda R(2) (LL R(2)) model, principal component analysis (PCA), and stepwise discriminant analysis (SDA); (ii) variable importance for projection (VIP) statistics derived from partial least square (PLS) regression (PLS-VIP); and (iii) multiple linear regression (MLR) analysis through maximum R-square improvement (MAXR) and stepwise algorithms. The discriminating capability of selected wavelengths was evaluated by canonical discriminant analysis. Leaf-nitrogen concentration was quantified on samples collected at the same locations and dates and used as response variable in regressive methods. The different methods resulted in differences in the number and position of the selected wavebands. Bands extracted through regressive methods were mostly related to response variable, as shown by the importance of the visible region for PLS and stepwise. Band selection techniques can be extremely useful not only to improve the power of predictive models but also for data interpretation or sensor design.
