Stories of young dropouts: a social survey of success and failure

info:eu-repo/semantics/publishedVersio

Evaluation of patients on sertindole treatment after failure of other antipsychotics: A retrospective analysis

<p>Abstract</p> <p>Background</p> <p>Use of the atypical antipsychotic sertindole was suspended for four years due to safety concerns. During the suspension, the regulatory authorities required further studies, including this one, to be conducted. The purpose of this study was to determine if a subset of patients with psychotic illness exists which particularly benefits from sertindole treatment after failure of other antipsychotic drugs, including atypical antipsychotics.</p> <p>Methods</p> <p>This was a retrospective single-arm observational crossover study of 344 patients, who served as their own controls. Patients mainly from the Sertindole Safety Study who had shown good response to sertindole, and who had followed up to four alternating six month periods of treatment with sertindole and other antipsychotics, were included. (In Period 1 patients took non-sertindole treatment, in Period 2, sertindole was taken, in Period 3, patients reverted to non-sertindole treatment, and in Period 4, sertindole was taken again.) Patient records for each period of treatment were assessed for objective data: number and duration of hospitalizations due to worsening of psychotic symptoms; the amount of self-harming behaviour; indicators of social status. Retrospective evaluation of changes in clinical symptoms from the patients' records was also conducted. Dates and reasons for stopping and/or switching medication were also recorded.</p> <p>Results</p> <p>There was improvement in all objective measured parameters during the periods of sertindole treatment. In particular, the average number of hospitalizations per year due to worsening of psychotic symptoms was reduced in the following way in the group studied over four treatment periods: Period 1 (non-sertindole treatment) 3.4; Period 2 (sertindole treatment) 1.0; Period 3 (non-sertindole treatment) 2.0; Period 4 (sertindole treatment) 1.8. The duration of hospitalizations also decreased significantly during the periods of sertindole treatment. Results showed that patients improved in objective social parameters when switched to sertindole treatment; assessment of the patients' affective lives showed a significant increase in the number of patients having a stable relationship during sertindole treatment; and assessment of the number of patients employed showed an increase after the first and second switch to sertindole treatment (from Period 1 to Period 2 and from Period 3 to Period 4, respectively).</p> <p>Adverse events and lack of efficacy were the main reasons for switching to sertindole.</p> <p>Conclusion</p> <p>A group of patients benefited from sertindole after other antipsychotic treatments, including that with atypical antipsychotics, had failed. Further studies are needed to investigate if there is a specific patient profile that corresponds to these responders.</p

Heteroskedasticity testing through a comparison of Wald statistics

This paper shows that a test for heteroskedasticity within the context of classical linear regression can be based on the difference between Wald statistics in heteroskedasticity-robust and nonrobust forms. The test is asymptotically distributed under the null hypothesis of homoskedasticity as chi-squared with one degree of freedom. The power of the test is sensitive to the choice of parametric restriction used by the Wald statistics, so the supremum of a range of individual test statistics is proposed. Two versions of a supremum-based test are considered: the first version does not have a known asymptotic null distribution, so the bootstrap is employed to approximate its empirical distribution. The second version has a known asymptotic distribution and, in some cases, is asymptotically pivotal under the null. A simulation study illustrates the use and finite-sample performance of both versions of the test. In this study, the bootstrap is found to provide better size control than asymptotic critical values, namely with heavy-tailed, asymmetric distributions of the covariates. In addition, the use of well-known modifications of the heteroskedasticity consistent covariance matrix estimator of OLS coefficients is also found to benefit the tests’ overall behaviour.info:eu-repo/semantics/publishedVersio

Determination of median in tabular and graphic context

Neste estudo, cujo objetivo é averiguar a influência do contexto dos dados na determinação da mediana, estudam-se as resoluções de 332 alunos portugueses do 8.º ano, a duas questões, uma com os dados organizados numa tabela de frequências e outra num gráfico de barras. Seguindo uma metodologia mista, quantitativa e qualitativa, realiza-se uma análise de frequências de quatro categorias ordinais de respostas (corretas, parcialmente corretas, incorretas e não respostas) e uma análise semiótica das resoluções aplicando o Enfoque Ontossemiótico do conhecimento e ensino da Matemática na identificação de objetos e processos matemáticos que intervêm nas resoluções. Em geral, os alunos revelaram maior propensão para não responderem à determinação da mediana em contexto gráfico, mas os que responderam tendem a determinar a mediana com menor dificuldade. Os conflitos semióticos identificados aparentam não estar dependentes da forma de apresentação dos dados, embora ocorra maior número de respostas não corretas no contexto tabelar do que no contexto gráficopublishe

binary and fractional regression models

generalized goodness-of-functional form test fo