Psychometric behaviour of the strengths and difficulties questionnaire (SDQ) in the Spanish national health survey 2006

Background: The Strengths and Difficulties Questionnaire (SDQ) is a tool to measure the risk for mental disorders in children. The aim of this study is to describe the diagnostic efficiency and internal structure of the SDQ in the sample of children studied in the Spanish National Health Survey 2006. Methods: A representative sample of 6,773 children aged 4 to 15 years was studied. The data were obtained using the Minors Questionnaire in the Spanish National Health Survey 2006. The ROC curve was constructed and calculations made of the area under the curve, sensitivity, specificity and the Youden J indices. The factorial structure was studied using models of exploratory factorial analysis (EFA) and confirmatory factorial analysis (CFA). Results: The prevalence of behavioural disorders varied between 0.47% and 1.18% according to the requisites of the diagnostic definition. The area under the ROC curve varied from 0.84 to 0.91 according to the diagnosis. Factor models were cross-validated by means of two different random subsamples for EFA and CFA. An EFA suggested a three correlated factor model. CFA confirmed this model. A five-factor model according to EFA and the theoretical five-factor model described in the bibliography were also confirmed. The reliabilities of the factors of the different models were acceptable (>0.70, except for one factor with reliability 0.62). Conclusions: The diagnostic behaviour of the SDQ in the Spanish population is within the working limits described in other countries. According to the results obtained in this study, the diagnostic efficiency of the questionnaire is adequate to identify probable cases of psychiatric disorders in low prevalence populations. Regarding the factorial structure we found that both the five and the three factor models fit the data with acceptable goodness of fit indexes, the latter including an externalization and internalization dimension and perhaps a meaningful positive social dimension. Accordingly, we recommend studying whether these differences depend on sociocultural factors or are, in fact, due to methodological questions.

How does family intervention improve the outcome of people with schizophrenia?

Background: There is strong evidence of the efficacy of family psychosocial interventions for schizophrenia, but evidence of the role played by the attitudes of relatives in the therapeutic process is lacking. Method: To study the effect of a family intervention on family attitudes and to analyse their mediating role in the therapeutic process 50 patients with schizophrenia and their key relatives undergoing a trial on the efficacy of a family psychosocial intervention were studied by means of the Affective Style Coding System, the Scale of Empathy, and the Relational Control Coding System. Specific statistical methods were used to determine the nature of the relationship of the relatives’ attitudes to the outcome of family intervention. Results: Family psychosocial intervention was associated with a reduction in relatives’ guilt induction and dominance and an improvement in empathy. Empathy and lack of dominance were identified as independent mediators of the effect of family psychosocial intervention. The change in empathy and dominance during the first 9 months of the intervention predicted the outcome in the following 15 months. Conclusion: Relatives’ empathy and lack of dominance are mediators of the beneficial effect of family psychosocial intervention on patient’s outcome.

Efectos del cambio climático y usos del suelo sobre los recursos hídricos de la cuenca del río Tordera (Barcelona, España)

Se presentan los efectos del cambio global en la cuenca del río Tordera (España) para el periodo 2000-2050, escenarios climáticos A2 (medio-alto) definidos por el Panel Intergubernamental del Cambio Climático (IPCC, 200) y escenarios socioeconómicos (cambios previstos en la cuenca) denominados estable y tendencial. Los efectos sobre los recursos hídricos se han analizado de forma conjunta superficial-subterránea mediante una metodológica de tipo acoplado. Para establecer los impactos futuros sobre los recursos hídricos se ha seleccionado el Modelo de Circulación Global ECHAM5 (Max Planck Institute). Los resultados obtenidos indican una disminución de la precipitación del 11.3% y un aumento de la temperatura de 1ºC, respecto a los valores históricos de la zona. De acuerdo a la proyección futura (2050) sobre cambios en los recursos hídricos, la escorrentía superficial obtenida mediante simulación con el código HEC-HMS 3.4 experimenta una reducción del 31.8% respecto al valor histórico y la recarga natural, estimada mediante VISUAL-Balan, se reduce en un 11.7%. El balance en el acuífero deltaico simulado mediante MODFLOW 2009.1 Pro muestra igualmente una disminución de los parámetros del balance. Los cambios del uso del suelo previstos de acuerdo a la legislación vigente (escenarios socioeconómicos) no conducen a la generación de un impacto apreciable en los recursos hídricos; según los escenarios definidos la variación de precipitación y temperatura son los parámetros fundamentales del cambio previsto.