This paper extends the multilevel survival model by allowing the existence of cured fraction in the model. Random effects induced by the multilevel clustering structure are specified in the linear predictors in both hazard function and cured probability parts. Adopting the generalized linear mixed model (GLMM) approach to formulate the problem, parameter estimation is achieved by maximizing a best linear unbiased prediction (BLUP) type log-likelihood at the initial step of estimation, and is then extended to obtain residual maximum likelihood (REML) estimators of the variance component. The proposed multilevel mixture cure model is applied to analyze the (i) child survival study data with multilevel clustering and (ii) chronic granulomatous disease (CGD) data on recurrent infections as illustrations. A simulation study is carried out to evaluate the performance of the REML estimators and assess the accuracy of the standard error estimates.
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http://dx.doi.org/10.1002/bimj.200800222 | DOI Listing |
The built and natural environment can facilitate (un)healthy behaviors in adolescence. However, most previous studies have focused on examining associations between singular aspects of the environment. This study examined the association between the mixture of health-promoting and health-constraining environmental features in a Healthy Location Index (HLI) and physical activity and screen time among adolescents.
View Article and Find Full Text PDFPsychol Methods
December 2024
Department of Educational Psychology, University of Texas at Austin.
This article walks through steps to conduct a meta-analysis of Monte Carlo simulation studies. The selected Monte Carlo simulation studies focused on mixture modeling, which is becoming increasingly popular in the social and behavioral sciences. We provide details for the following steps in a meta-analysis: (a) formulating a research question; (b) identifying the relevant literature; (c) screening of the literature; (d) extracting data; (e) analyzing the data; and (f) interpreting and discussing the findings.
View Article and Find Full Text PDFBMJ Open
December 2024
Clinical Radiology, Great Ormond Street Hospital for Children, London, UK.
Introduction: Paediatric fractures are common but can be easily missed on radiography leading to potentially serious implications including long-term pain, disability and missed opportunities for safeguarding in cases of inflicted injury. Artificial intelligence (AI) tools to assist fracture detection in adult patients exist, although their efficacy in children is less well known. This study aims to evaluate whether a commercially available AI tool (certified for paediatric use) improves healthcare professionals (HCPs) detection of fractures, and how this may impact patient care in a retrospective simulated study design.
View Article and Find Full Text PDFPoult Sci
November 2024
College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Road, Xiangfang District, Harbin 150030, PR China; Institute of Chinese Materia Medica, Heilongjiang Academy of Chinese Medicine Sciences, Harbin 150036, PR China. Electronic address:
Natural drugs possess exceptional pharmacological properties, yet their development is often hindered by a lack of clarity regarding the mechanisms of their pharmacological actions. Building on our previous research, we employed a co-infection model with Mycoplasma gallisepticum (MG) and Escherichia coli (E. coli) to investigate the pharmacological action of Radix Isatidis Mixtures (RIM).
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November 2024
Farming Systems Ecology, Wageningen University and Research, Wageningen, the Netherlands.
Agroecology is among the most promising options to alleviate the negative impacts of animal farming on the environment and build local food systems based on ethically acceptable production methods. So far, most of the research on agroecological animal production systems was conducted at farm scale, and the potential of agroecological principles addressing social dimensions and food system-level approaches has been underexplored. Here, we analyse how the whole set of agroecological principles was mobilised in five case studies on grassland-based, silvopastoral or integrated crop-livestock systems in Switzerland, Guadeloupe, French uplands, Bulgaria and Andalucía.
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