ABSTRACT
INTRODUÇÃO: Diversos estudos mostram o Funcionamento Diferencial do Item (DIF) em itens do Inventário de Depressão Beck (BDI), ao compararem homens e mulheres. A presença de um grande número de itens com DIF no BDI é uma severa ameaça à validade da medida da intensidade de sintomas depressivos obtida pela Teoria da Resposta ao Item (TRI) e às conclusões baseadas nos escores derivados dos itens com e sem DIF. OBJETIVO: Os objetivos deste estudo foram identificar esses itens do BDI, ajustar o modelo de TRI para itens constrangedores (modelo 2), o qual acomoda itens com a presença de DIF, e comparar esses resultados com os do ajuste do modelo logístico de dois parâmetros tradicional da TRI (modelo 1). MÉTODOS: Os resultados obtidos com ambos os modelos foram comparados. RESULTADOS: Os itens que apresentaram DIF foram: tristeza, sentimento de fracasso, insatisfações, culpa, punição, choro, fatigabilidade e perda da libido. Os resultados do ajuste dos dois modelos são similares quanto à discriminação, gravidade (à exceção dos itens com DIF) e no cálculo de escores para os indivíduos. Apesar disso, o modelo 2 é vantajoso, pois mostra as diferenças em gravidade do sintoma depressivo para os grupos avaliados, trazendo, dessa forma, mais informação ao pesquisador sobre a população estudada. CONCLUSÃO: Esse modelo, que tem um alcance mais amplo em termos de população-alvo, pode ser uma ótima alternativa na identificação e acompanhamento de indivíduos com potencial depressivo. .
INTRODUCTION: There are several studies showing the presence of Differential Item Functioning (DIF) in some items of the Beck Depression Inventory (BDI), when comparing men and women. The presence of a large number of items with DIF in BDI is a severe threat to the validity of measurement of the intensity of depressive symptoms obtained by Item Response Theory (IRT) and to the conclusions based on the scores derived from the items with or without DIF. OBJECTIVE: The objectives of this study were to identify these items from the BDI, adjust the IRT model for embarrassing items (model 2), which accommodates items with the presence of DIF, and compare these results with the fit of the traditional two-parameter logistic IRT model (model 1). METHODS: The results obtained with the both models were compared. RESULTS: Items with DIF were: sadness, feeling of failure, dissatisfaction, guilty, punishment, crying, fatigability and loss of libido. The results of the adjustment of the two models are similar in discrimination, gravity (except for items with DIF), and in the calculation of scores for individuals. Nevertheless, model 2 is beneficial because it shows the differences in gravity of depressive symptoms for groups evaluated, thus providing more information to the researcher on the study population. CONCLUSION: This model, which has a broader scope in terms of target population, may be a good alternative to the identification and follow-up of individuals with potential depression. .
Subject(s)
Humans , Male , Female , Adult , Depression , Depression/epidemiology , Models, StatisticalABSTRACT
OBJECTIVE: Academic examinations are an important source of stress for students. This study is intended to assess senior high school students' mood changes during the preparation for a very important academic examination, the Brazilian university admission examination. METHOD: Positive and Negative Affect Schedule - Expanded Form was used to assess the students three times in the course of the months preceding the examination. RESULTS: ANOVA for repeated measures showed that Negative Affect increased as the examination approached, and that this increment was already present months before the examinationtookplace. Asingle conditionallyindependent random effect model showed that time spent studying was associated with fluctuations in mood. CONCLUSION: Teenagers, in preparation for a very important examination, may present mood disturbances associated with both the proximity of the examination and their study load months before the examination actually takes place. Other stressing factors may play a role in these findings and should be further investigated.
OBJETIVO: Exames acadêmicos são uma fonte importante de estresse para estudantes. Este estudo teve como objetivo avaliar alterações de humor em estudantes de terceiro ano do Ensino Médio ao longo da preparação para um exame acadêmico de grande importância, o vestibular. MÉTODO: Positive and Negative Affect Schedule - Expanded Form foi utilizado para avaliar os estudantes três vezes ao longo dos meses antecedendo o exame. RESULTADOS: ANOVA para medidas repetidas mostrou que o afeto negativo aumentou com a aproximação do exame e que esse aumento já estava presente meses antes dele acontecer. Um modelo de efeitos aleatórios com independência condicional mostrou que o tempo de estudo estava associado às flutuações de humor. CONCLUSÃO: Adolescentes em preparação para exames muito importantes podem apresentar um distúrbio de humor associado à proximidade do exame e à quantidade de estudo meses antes que ele ocorra. Outros estressores podem estar associados a esses achados e devem ser investigados.
Subject(s)
Adolescent , Female , Humans , Male , Affect , Affective Symptoms/psychology , Education, Medical, Undergraduate , School Admission Criteria , Stress, Psychological , Students/psychology , Analysis of Variance , Brazil , Longitudinal Studies , Sex DistributionABSTRACT
OBJECTIVE: To investigate the role of hemodynamic changes occurring during acute MI in subsequent fibrosis deposition within non-MI. METHODS: By using the rat model of MI, 3 groups of 7 rats each [sham, SMI (MI <30 percent), and LMI (MI >30 percent)] were compared. Systemic and left ventricular (LV) hemodynamics were recorded 10 minutes before and after coronary artery ligature. Collagen volume fraction (CVF) was calculated in picrosirius red-stained heart tissue sections 4 weeks later. RESULTS: Before surgery, all hemodynamic variables were comparable among groups. After surgery, LV end-diastolic pressure increased and coronary driving pressure decreased significantly in the LMI compared with the sham group. LV dP/dt max and dP/dt min of both the SMI and LMI groups were statistically different from those of the sham group. CVF within non-MI interventricular septum and right ventricle did not differ between each MI group and the sham group. Otherwise, subendocardial (SE) CVF was statistically greater in the LMI group. SE CVF correlated negatively with post-MI systemic blood pressure and coronary driving pressure, and positively with post-MI LV dP/dt min. Stepwise regression analysis identified post-MI coronary driving pressure as an independent predictor of SE CVF. CONCLUSION: LV remodeling in rats with MI is characterized by predominant SE collagen deposition in non-MI and results from a reduction in myocardial perfusion pressure occurring early on in the setting of MI