The Gamma-Poisson model, i.e., a Poisson distribution where the parameter lambda is Gamma distributed, has been suggested as a statistical method for determining whether or not micro-organisms are randomly distributed in a food matrix. In this study, we analyse the Gamma-Poisson model to explore some of the properties of the Gamma-Poisson model left unexplored by the previous study. The conclusion of our analysis is that the Gamma-Poisson model distinguishes poorly between variation at the Poisson level and the Gamma level. Estimated parameter values from simulated data-sets showed large variation around the true values, even for moderate sample sizes (n=100). Furthermore, at these sample sizes the likelihood ratio is not a good test statistic for discriminating between the Gamma-Poisson distribution and the Poisson distribution. Hence, to determine if data are randomly distributed, i.e., Poisson distributed, the Gamma-Poisson distribution is not a good choice. However, the ratio between variation at the Poisson level and the Gamma level does provide a measure of the amount of overdispersion.
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http://dx.doi.org/10.1016/j.fm.2005.01.014 | DOI Listing |
Sci Rep
January 2025
Department of Dermatology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China.
Brodalumab, a humanized monoclonal antibody that targets the interleukin-17 receptor A, is primarily used to manage moderate-to-severe plaque psoriasis. Although it has demonstrated favorable efficacy and safety in clinical trials, the strict inclusion and exclusion criteria may not fully reflect its safety profile in real-world settings. As its use becomes more widespread in clinical practice, understanding its safety in real-world applications is crucial.
View Article and Find Full Text PDFTher Adv Drug Saf
January 2025
College of Pharmacy, Jinan University, Guangzhou, Guangdong 511436, China.
Expert Opin Drug Saf
December 2024
Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Child Neurodevelopment and Cognitive Disorders, Chongqing, China.
Contemp Clin Trials Commun
December 2024
Department of Medicine, Université de Montréal, Québec, Canada.
It is important for researchers to carefully assess the feasibility of a clinical trial prior to the launch of the study. One feasibility aspect that needs to be considered includes whether investigators can expect to successfully achieve the sample size needed for their trial. In this manuscript, we present a Bayesian design in which data collected during a pilot study is used to predict the feasibility of a planned phase III trial.
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