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1.
Trials ; 25(1): 113, 2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38336761

RESUMO

BACKGROUND: Statisticians are fundamental in ensuring clinical research, including clinical trials, are conducted with quality, transparency, reproducibility and integrity. Good Clinical Practice (GCP) is an international quality standard for the conduct of clinical trials research. Statisticians are required to undertake training on GCP but existing training is generic and, crucially, does not cover statistical activities. This results in statisticians undertaking training mostly unrelated to their role and variation in awareness and implementation of relevant regulatory requirements with regards to statistical conduct. The need for role-relevant training is recognised by the UK NHS Health Research Authority and the Medicines and Healthcare products Regulatory Agency (MHRA). METHODS: The Good Statistical Practice (GCP for Statisticians) project was instigated by the UK Clinical Research Collaboration (UKCRC) Registered Clinical Trials Unit (CTU) Statisticians Operational Group and funded by the National Institute for Health and Care Research (NIHR), to develop materials to enable role-specific GCP training tailored to statisticians. Review of current GCP training was undertaken by survey. Development of training materials were based on MHRA GCP. Critical review and piloting was conducted with UKCRC CTU and NIHR researchers with comment from MHRA. Final review was conducted through the UKCRC CTU Statistics group. RESULTS: The survey confirmed the need and desire for the development of dedicated GCP training for statisticians. An accessible, comprehensive, piloted training package was developed tailored to statisticians working in clinical research, particularly the clinical trials arena. The training materials cover legislation and guidance for best practice across all clinical trial processes with statistical involvement, including exercises and real-life scenarios to bridge the gap between theory and practice. Comprehensive feedback was incorporated. The training materials are freely available for national and international adoption. CONCLUSION: All research staff should have training in GCP yet the training undertaken by most academic statisticians does not cover activities related to their role. The Good Statistical Practice (GCP for Statisticians) project has developed and extensively piloted new, role-specific, comprehensive, accessible GCP training tailored to statisticians working in clinical research, particularly the clinical trials arena. This role-specific training will encourage best practice, leading to transparent and reproducible statistical activity, as required by regulatory authorities and funders.


Assuntos
Ensaios Clínicos como Assunto , Estatística como Assunto , Humanos , Reprodutibilidade dos Testes , Estatística como Assunto/normas
2.
Orphanet J Rare Dis ; 18(1): 391, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38115074

RESUMO

BACKGROUND: Recommendations for statistical methods in rare disease trials are scarce, especially for cross-over designs. As a result various state-of-the-art methodologies were compared as neutrally as possible using an illustrative data set from epidermolysis bullosa research to build recommendations for count, binary, and ordinal outcome variables. For this purpose, parametric (model averaging), semiparametric (generalized estimating equations type [GEE-like]) and nonparametric (generalized pairwise comparisons [GPC] and a marginal model implemented in the R package nparLD) methods were chosen by an international consortium of statisticians. RESULTS: It was found that there is no uniformly best method for the aforementioned types of outcome variables, but in particular situations, there are methods that perform better than others. Especially if maximizing power is the primary goal, the prioritized unmatched GPC method was able to achieve particularly good results, besides being appropriate for prioritizing clinically relevant time points. Model averaging led to favorable results in some scenarios especially within the binary outcome setting and, like the GEE-like semiparametric method, also allows for considering period and carry-over effects properly. Inference based on the nonparametric marginal model was able to achieve high power, especially in the ordinal outcome scenario, despite small sample sizes due to separate testing of treatment periods, and is suitable when longitudinal and interaction effects have to be considered. CONCLUSION: Overall, a balance has to be found between achieving high power, accounting for cross-over, period, or carry-over effects, and prioritizing clinically relevant time points.


Assuntos
Doenças Raras , Projetos de Pesquisa , Estatística como Assunto , Humanos , Estudos Cross-Over , Tamanho da Amostra
4.
Genet Epidemiol ; 47(8): 637-641, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37947279

RESUMO

The comparison of biological systems, through the analysis of molecular changes under different conditions, has played a crucial role in the progress of modern biological science. Specifically, differential correlation analysis (DCA) has been employed to determine whether relationships between genomic features differ across conditions or outcomes. Because ascertaining the null distribution of test statistics to capture variations in correlation is challenging, several DCA methods utilize permutation which can loosen parametric (e.g., normality) assumptions. However, permutation is often problematic for DCA due to violating the assumption that samples are exchangeable under the null. Here, we examine the limitations of permutation-based DCA and investigate instances where the permutation-based DCA exhibits poor performance. Experimental results show that the permutation-based DCA often fails to control the type I error under the null hypothesis of equal correlation structures.


Assuntos
Genômica , Humanos , Estatística como Assunto
5.
Med Decis Making ; 43(7-8): 774-788, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37872798

RESUMO

OBJECTIVE: People differ in whether they understand graphical or numerical representations of statistical information better. However, assessing these skills is often not feasible when deciding which representation to select or use. This study investigates whether people choose the representation they understand better, whether this choice can improve risk comprehension, and whether results are influenced by participants' skills (graph literacy and numeracy). METHODS: In an experiment, 160 participants received information about the benefits and side effects of painkillers using either a numerical or a graphical representation. In the "no choice" condition, the representation was randomly assigned to each participant. In the "choice" condition, participants could select the representation they would like to receive. The study assessed gist and verbatim knowledge (immediate comprehension and recall), accessibility of the information, attractiveness of the representation, as well as graph literacy and numeracy. RESULTS: In the "choice" condition, most (62.5%) chose the graphical format, yet there was no difference in graph literacy or numeracy (nor age or gender) between people who chose the graphical or the numerical format. Whereas choice slightly increased verbatim knowledge, it did not improve gist or overall knowledge compared with random assignment. However, participants who chose a representation rated the representation as more attractive, and those who chose graphs rated them as more accessible than those without a choice. LIMITATIONS: The sample consisted of highly educated undergraduate students with higher graph literacy than the general population. The task was inconsequential for participants in terms of their health. CONCLUSIONS: When people can choose between representations, they fail to identify what they comprehend better but largely base that choice on how attractive the representation is for them. HIGHLIGHTS: People differ systematically in whether they understand graphical or numerical representations of statistical information better. However, assessing these underlying skills to get the right representation to the right people is not feasible in practice. A simple and efficient method to achieve this could be to let people choose among representations themselves.However, our study showed that allowing participants to choose a representation (numerical v. graphical) did not improve overall or gist knowledge compared with determining the representation randomly, even though it did slightly improve verbatim knowledge.Rather, participants largely chose the representation they found more attractive. Most preferred the graphical representation, including those with low graph literacy.It would therefore be important to develop graphical representations that are not only attractive but also comprehensible even for people with low graph literacy.


Assuntos
Compreensão , Estatística como Assunto , Humanos , Rememoração Mental
8.
Rev. neurol. (Ed. impr.) ; 77(7)1 - 15 de Octubre 2023. tab
Artigo em Espanhol | IBECS | ID: ibc-226080

RESUMO

Cuando el investigador pide subvención y autorización a entidades financieras para llevar a cabo su proyecto, entre las primeras cuestiones que le plantean está: ¿qué potencia estadística tiene este estudio que usted propone? Si el investigador responde, por ejemplo, el 90%, y el evaluador se da por satisfecho, es seguro que no conoce realmente el tema. La potencia de un estudio no es única. Depende de determinados parámetros y ocurre que, en la mayoría de los casos, variando ligeramente los valores de esos parámetros, la potencia toma un valor aceptable. Si no es así, y a pesar de ello se lleva a cabo el estudio, y sus resultados son muy significativos, no ha lugar a cuestionar el éxito encontrado argumentando que el estudio tenía poca potencia. Tan sólo es momento de celebrarlo. (AU)


When researchers request funding and authorisation from financial institutions to carry out their project, one of the first questions they are asked is: what is the statistical power of the study you are proposing? If the researcher answers, for example, 90%, and the evaluator is satisfied, it is certain that he/she is not really familiar with the subject. The power of a study is not unique. It depends on certain parameters and what happens is that, in most cases, by introducing a slight variation in the values of these parameters, the power takes on an acceptable value. If this is not the case and the study is carried out anyway, and its results are very significant, there is no room to question its success by arguing that the power of the study was very low. It is just the time to celebrate. (AU)


Assuntos
Distribuições Estatísticas , Interpretação Estatística de Dados , Modelos Estatísticos , Indicadores (Estatística) , Medição de Risco/métodos , Medição de Risco/estatística & dados numéricos , Estatística como Assunto
11.
Rev Neurol ; 77(7): 171-173, 2023 10 01.
Artigo em Espanhol | MEDLINE | ID: mdl-37750548

RESUMO

When researchers request funding and authorisation from financial institutions to carry out their project, one of the first questions they are asked is: what is the statistical power of the study you are proposing? If the researcher answers, for example, 90%, and the evaluator is satisfied, it is certain that he/she is not really familiar with the subject. The power of a study is not unique. It depends on certain parameters and what happens is that, in most cases, by introducing a slight variation in the values of these parameters, the power takes on an acceptable value. If this is not the case and the study is carried out anyway, and its results are very significant, there is no room to question its success by arguing that the power of the study was very low. It is just the time to celebrate.


TITLE: Potencia estadística en investigación médica. ¿Qué postura tomar cuando los resultados de la investigación son significativos?Cuando el investigador pide subvención y autorización a entidades financieras para llevar a cabo su proyecto, entre las primeras cuestiones que le plantean está: ¿qué potencia estadística tiene este estudio que usted propone? Si el investigador responde, por ejemplo, el 90%, y el evaluador se da por satisfecho, es seguro que no conoce realmente el tema. La potencia de un estudio no es única. Depende de determinados parámetros y ocurre que, en la mayoría de los casos, variando ligeramente los valores de esos parámetros, la potencia toma un valor aceptable. Si no es así, y a pesar de ello se lleva a cabo el estudio, y sus resultados son muy significativos, no ha lugar a cuestionar el éxito encontrado argumentando que el estudio tenía poca potencia. Tan sólo es momento de celebrarlo.


Assuntos
Pesquisa Biomédica , Humanos , Estatística como Assunto , Relevância Clínica
12.
Rev. esp. anestesiol. reanim ; 70(7): 381-386, Agos-Sept- 2023. ilus, tab, graf
Artigo em Espanhol | IBECS | ID: ibc-223995

RESUMO

Antecedentes y objetivo: Cada vez hay más estudios que evidencian que las ecuaciones utilizadas para conocer la tasa de filtrado glomerular estimada (TFGe) no son adecuadas para los pacientes críticos en los que se producen continuas variaciones del filtrado glomerular (FG). El método más práctico para aproximarse al estudio del FG es el cálculo del aclaramiento de creatinina (ClCr) en periodos de recogida de orina variables. El objetivo del estudio fue observar el comportamiento de las ecuaciones empleadas para estimar el filtrado glomerular cuando se aplican a la subpoblación de pacientes críticos ingresados por trauma grave y comparar el ClCr en orina recogida en un periodo de 4horas (ClCr-4h). Material y métodos: Estudio observacional que incluye pacientes ingresados por trauma grave. Se calculó el ClCr-4h y se determinó la TFGe mediante las ecuaciones de Cockcroft-Gault, Jelliffe modificada, MDRD, t-MDRD y CKD-EPI. Los resultados se expresan referidos a superficie corporal (ml/min/1,73m2). Los análisis se realizaron con el software estadístico R versión 4.0.4. Resultados: Se incluyeron 85 pacientes. La edad mediana de los pacientes fue de 51años; 68 pacientes fueron varones (78,82%). El ClCr-4h ajustado a superficie corporal (ClCr-4h ml/min/1,73m2) medio fue de 84,5ml/min/1,73m2. Hallamos correlación estadísticamente significativa de ClCr-4h/1,73m2 con la TFGe por t-MDRD. Para ClCr-4h/1,73m2 mayores de 130ml/min/m2 la ecuación de Cockcroft-Gault identifica a los pacientes correctamente de una forma estadísticamente significativa. Conclusiones: El cálculo de ClCr en el entorno de UCI proporciona datos fiables del FG, no siendo adecuado el uso de ecuaciones estimativas.(AU)


Background and objective: There is a growing body of evidence that the equations used to estimate the glomerular filtration rate (GFR) are not suitable in critically ill patients, a population whose GFR fluctuates continuously. Glomerular filtration is usually estimated by measuring urine creatinine clearance (CrCl) at various time points. The aim of our study was to evaluate the performance of the most widely used GFR calculators in the subpopulation of critically ill patients admitted for severe trauma, and to compare the results against determinations of CrCl in urine collected over a 4-hour period (4h-CrCl). Material and methods: Observational study in patients hospitalized for severe trauma. We measured the 4h-CrCl and estimated GFR using the Cockcroft-Gault, modified Jelliffe, MDRD, t-MDRD, and CKD-EPI equations, adjusting the results for body surface area (BSA) (ml/min/1.73m2). Data were analysed using R version 4.0.4. Results: A total of 85 patients were included. Median age was 51years, and 68 were men (78.82%). The mean BSA-adjusted 4h-CrCl (4h-ClCr/1.73m2) was 84.5ml/min/1.73m2. We found that GFR estimated using the t-MDRD equation correlated significantly with 4h-CrCl/1.73m2. The Cockcroft-Gault equation correlated significantly with 4h-CrCl/1.73m2 when GFR was greater than 130ml/min/m2. Conclusions: In ICU patients, glomerular filtration can be reliably estimated by determining urine CrCl, but GFR calculators are not accurate in this population.(AU)


Assuntos
Humanos , Masculino , Feminino , Creatinina/urina , Taxa de Filtração Glomerular , Urinálise , Anestesiologia , Pacientes Internados , Estatística como Assunto , Espanha/epidemiologia
13.
Stat Med ; 42(22): 4043-4055, 2023 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-37443445

RESUMO

We consider the semiparametric accelerated failure time (AFT) model with multiple covariates measured with error. Existing methods for the AFT model are either inconsistent, computationally intensive, or require stringent assumptions. To overcome these limitations, we develop a correction approach for a general smooth function of error-contaminated variables. We apply this method to the smoothed rank-based score function for the AFT model. The estimator is consistent and asymptotically normal. The finite-sample performance of the method is assessed by simulation studies. The approach is illustrated by application to data from an HIV clinical trial.


Assuntos
Simulação por Computador , Estatística como Assunto , Humanos
14.
Pharm Stat ; 22(6): 1135-1140, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37431704

RESUMO

The role and value of statistical contributions in drug development up to the point of health authority approval are well understood. But health authority approval is only a true 'win' if the evidence enables access and adoption into clinical practice. In today's complex and evolving healthcare environment, there is additional strategic evidence generation, communication, and decision support that can benefit from statistical contributions. In this article, we describe the history of medical affairs in the context of drug development, the factors driving post-approval evidence generation needs, and the opportunities for statisticians to optimize evidence generation for stakeholders beyond health authorities in order to ensure that new medicines reach appropriate patients.


Assuntos
Desenvolvimento de Medicamentos , Desenvolvimento de Medicamentos/legislação & jurisprudência , Estatística como Assunto
15.
Stat Med ; 42(21): 3838-3859, 2023 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-37345519

RESUMO

Unmeasured confounding is a major obstacle to reliable causal inference based on observational studies. Instrumented difference-in-differences (iDiD), a novel idea connecting instrumental variable and standard DiD, ameliorates the above issue by explicitly leveraging exogenous randomness in an exposure trend. In this article, we utilize the above idea of iDiD, and propose a novel group sequential testing method that provides valid inference even in the presence of unmeasured confounders. At each time point, we estimate the average or conditional average treatment effect under iDiD setting using the data accumulated up to that time point, and test the significance of the treatment effect. We derive the joint distribution of the test statistics under the null using the asymptotic properties of M-estimation, and the group sequential boundaries are obtained using the α $$ \alpha $$ -spending functions. The performance of our proposed approach is evaluated on both synthetic data and Clinformatics Data Mart Database (OptumInsight, Eden Prairie, MN) to examine the association between rofecoxib and acute myocardial infarction, and our method detects significant adverse effect of rofecoxib much earlier than the time when it was finally withdrawn from the market.


Assuntos
Viés , Estatística como Assunto , Humanos , Infarto do Miocárdio , Retirada de Medicamento Baseada em Segurança
16.
Medwave ; 23(5)2023 Jun 06.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-37279463

RESUMO

The increasing production of primary research and literature reviews in the last decades has made it necessary to develop a new methodological design to synthesize the evidence: the overviews. An overview is a type of evidence synthesis that uses systematic reviews as the unit of analysis, with the aim of extracting and analyzing the results for a new or broader research question, helping the shared decision-making processes. The aim of this article is to introduce the reader to this type of evidence summaries, highlighting the differences between overviews and other types of synthesis, the unique methodological aspects of overviews, and future challenges. This is the twelfth article from a collaborative methodological series of narrative reviews about biostatistics and clinical epidemiology.


El aumento de la producción de investigación primaria y de las revisiones de la literatura durante las últimas décadas ha hecho necesario el desarrollo de un nuevo diseño metodológico para sintetizar la evidencia: los overviews. Un overview es un diseño de síntesis de evidencia que toma como unidad de análisis a las revisiones sistemáticas, con el objetivo de extraer y analizar los resultados para una pregunta de interés nueva o más amplia, ayudando así a mejorar los procesos de toma de decisiones informadas. El objetivo de este artículo es introducir al lector a este tipo de resúmenes de evidencia, destacando las diferencias con los otros tipos de síntesis de evidencia, los aspectos metodológicos particulares de los overviews, y los desafíos pendientes. Este artículo es el duodécimo de una serie metodológica colaborativa de revisiones narrativas sobre temáticas de bioestadística y epidemiología clínica.


Assuntos
Medicina Baseada em Evidências , Humanos , Revisões Sistemáticas como Assunto , Estatística como Assunto
18.
Av. odontoestomatol ; 39(2)abr.-jun. 2023. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-223398

RESUMO

Objetivo: Evaluar la precisión de la estimación del sexo y edad utilizando la morfometría de la rama mandibular mediante un modelo de regresión lineal múltiple incluyendo el ancho intercondilear, el ancho bigonial, la longitud coronoides, la longitud de la rama mandibular, la longitud del cóndilo, el ancho máximo de la rama mandibular y el ángulo goniaco en una población adulta peruana 2014-2019. Material y métodos: Se utilizaron 174 tomografías computarizadas de 18 a 60 años de edad y se analizaron las variables ancho intercondileo (AI), ancho bigonial (AB), longitud coronoides (LCr), longitud del cóndilo (LC), longitud de la rama mandibular (LRm), ancho máximo de la rama mandibular (AMRm) y ángulo goniaco (AG) del lado derecho de la mandíbula. Resultados: La prueba t de muestras independientes determinó que la mayor diferencia entre el sexo fue en la variable LC con 6.9225 mm, la función discriminante obtuvo una tasa de clasificación correcta del sexo con 82.7% y con el modelo de regresión logística múltiple se obtuvo una sensibilidad en el sexo femenino de 81.2%, una especificidad de 85.7%, el sexo masculino una sensibilidad de 85.7%, una especificidad de 81.2%, en la edad la correlación más alta fue en AG con -0.252. Conclusión: Los coeficientes más potentes fueron en LRm, AI y AB con 0.608, 0.606 y 0.604 respectivamente. La mayor diferencia se encontró en el ancho intercondilar con 9.3 mm entre los sexos, en general el porcentaje de precisión predictiva fue de 83.9% en una población egipcia muy parecido a este estudio. (AU)


Objective: To evaluate the precision of the estimation of sex and age using the morphometry of the mandibular ramus through a multiple linear regression model including the intercondylar width, the bigonial width, the coronoid length, the length of the mandibular ramus, the length of the condyle, the maximum width of the mandibular ramus and the gonial angle in a Peruvian adult population 2014-2019. Material and methods: 174 computed tomography scans from 18 to 60 years of age were used and the variables intercondylar width (AI), bigonial width (AB), coronoid length (CLr), condyle length (LC), ramus length mandibular ramus (MRm), maximum width of the mandibular ramus (MRAm) and gonial angle (AG) of the right side of the mandible. Results: The independent samples t-test determined that the greatest difference between the sexes was in the LC variable with 6.9225 mm, the discriminant function obtained a correct classification rate of the sex with 82.7% and with the multiple logistic regression model a sensitivity in the female sex of 81.2%, a specificity of 85.7%, the male sex a sensitivity of 85.7%, a specificity of 81.2%, in age the highest correlation was in AG with -0.252. Discussion: The most powerful coefficients were in LRm, AI and AB with 0.608, 0.606 and 0.604 respectively. The greatest difference was found in the intercondylar width with 9.3 mm between the sexes, in general the percentage of predictive accuracy was 83.9% in an Egyptian population very similar to this study. (AU)


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Achados Morfológicos e Microscópicos , Modelos Estatísticos , Mandíbula/crescimento & desenvolvimento , Distribuição por Idade e Sexo , Estatística como Assunto , Peru/etnologia
20.
Stat Med ; 42(17): 2944-2961, 2023 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-37173292

RESUMO

Modern high-throughput biomedical devices routinely produce data on a large scale, and the analysis of high-dimensional datasets has become commonplace in biomedical studies. However, given thousands or tens of thousands of measured variables in these datasets, extracting meaningful features poses a challenge. In this article, we propose a procedure to evaluate the strength of the associations between a nominal (categorical) response variable and multiple features simultaneously. Specifically, we propose a framework of large-scale multiple testing under arbitrary correlation dependency among test statistics. First, marginal multinomial regressions are performed for each feature individually. Second, we use an approach of multiple marginal models for each baseline-category pair to establish asymptotic joint normality of the stacked vector of the marginal multinomial regression coefficients. Third, we estimate the (limiting) covariance matrix between the estimated coefficients from all marginal models. Finally, our approach approximates the realized false discovery proportion of a thresholding procedure for the marginal p-values for each baseline-category logit pair. The proposed approach offers a sensible trade-off between the expected numbers of true and false findings. Furthermore, we demonstrate a practical application of the method on hyperspectral imaging data. This dataset is obtained by a matrix-assisted laser desorption/ionization (MALDI) instrument. MALDI demonstrates tremendous potential for clinical diagnosis, particularly for cancer research. In our application, the nominal response categories represent cancer (sub-)types.


Assuntos
Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Humanos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Estatística como Assunto
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