Search results for "Random effects model"
showing 10 items of 49 documents
Is device-measured vigorous physical activity associated with health-related outcomes in children and adolescents? A systematic review and meta-analy…
2021
Highlights • Higher vigorous-intensity physical activity seems to be negatively related to adiposity and cardiometabolic risk score among children and adolescents later in life. • Higher vigorous-intensity physical activity is positively related to cardiorespiratory fitness and total body bone mineral density among children and adolescents later in life. • The present results support the need to further strengthen vigorous-intensity physical activity recommendations for children and adolescents.
Orthotopic Liver Transplantation: T-Tube or Not T-Tube? Systematic Review and Meta-Analysis of Results
2009
Background The purpose of this study was to compare outcomes after duct-to-duct anastomoses with or without biliary T-tube in orthotopic liver transplantation. Methods We pooled the outcomes of 1027 patients undergoing choledocho-choledochostomy with or without T-tube in 9 of 46 screened trials by means of fixed or random effects models. Results The "without T-tube" and "with T-tube" groups had equivalent outcomes for: anastomotic bile leaks or fistulas, choledocho-jejunostomy revisions, dilatation and stenting, hepatic artery thromboses, retransplantation, and mortality due to biliary complications. The "without T-tube" group had better outcomes when considering "fewer episodes of cholangi…
La sopravvivenza immediata delle start-up italiane del settore manifatturiero sanitario: un'analisi multilevel
2017
The immediate survival of the Italian start-up businesses in healthcare industry: a multilevel analysis Objectives: The purpose of this contribution is to provide novel evidence about the main determinants of the short-run survival of pharmaceutical and medical device manufacturing start-up firms in Italy. In order to assess both the firm-specific determinants and the observed and unobserved regional and contextual characteristics, we model the three-year firm survival probability by means of a multilevel logistic framework. Methods and Results: The empirical analysis focuses on an internationally comparable database of the population of firms built up and managed by the Italian National In…
Bayesian joint models for longitudinal and survival data
2020
This paper takes a quick look at Bayesian joint models (BJM) for longitudinal and survival data. A general formulation for BJM is examined in terms of the sampling distribution of the longitudinal and survival processes, the conditional distribution of the random effects and the prior distribution. Next a basic BJM defined in terms of a mixed linear model and a Cox survival regression models is discussed and some extensions and other Bayesian topics are briefly outlined.
An Ordinal Joint Model for Breast Cancer
2017
We propose a Bayesian joint model to analyze the association between longitudinal measurements of an ordinal marker and time to a relevant event. The longitudinal process is defined in terms of a proportional-odds cumulative logit model and the time-to-event process through a left-truncated Cox proportional hazards model with information of the longitudinal marker and baseline covariates. Both longitudinal and survival processes are connected by a common vector of random effects.
Healthcare costs of the SATisfaction and adherence to COPD treatment (SAT)study follow-up
2019
Abstract Background Chronic obstructive pulmonary disease (COPD) is characterised by recurring exacerbations. We estimated the costs of healthcare resources for COPD management funded by the Italian National Healthcare Service (INHS) for one year. Methods We examined the demographic, clinical, and economic variables at enrolment and follow-up visits (at 6 and 12 months) of COPD patients participating in the SAT study and referred to 20 Italian pulmonary centres with different institutional characteristics. Costs were expressed in Euro (€) 2018. A random effects log-linear panel regression model was performed to predict the average cost per patient. Results Most of the centres were public in…
COVID-19 y tabaquismo: revisión sistemática y metaanálisis de la evidencia
2021
RESUMEN Objetivo: el objetivo del estudio ha sido responder a las siguientes preguntas: ¿Se asocia el consumo de tabaco en pacientes con Covid-19 con una progresión negativa y desenlace adverso de la enfermedad? y, ¿se asocia el consumo de tabaco, actual y pasado, a una mayor posibilidad de desarrollar COVID-19? Material y Métodos: Se realizó una revisión sistemática (RS) y metaanálisis (MA) de trabajos publicados previamente. La estrategia de búsqueda incluyó todos los descriptores conocidos sobre Covid-19 y tabaco y se realizó en diferentes bases de datos. Se utilizaron modelos estadísticos adecuados para abordar el tamaño del efecto en un metaanálisis: modelo de efectos aleatorios y de e…
Aspirin use and breast cancer risk: a meta-analysis and meta-regression of observational studies from 2001 to 2005
2007
Purpose To examine the recent epidemiological studies on aspirin use and breast cancer risk published from 2001 to 2005 within a meta-analysis, to investigate reasons for heterogeneity between the individual studies and to analyse a dose-response-relationship considering frequency and duration of use. Methods We systematically searched for cohort-studies and case-control-studies from 2001–2005, which evaluated the association between aspirin and breast cancer risk. We calculated a pooled estimate for the relative risk (RR) and investigated reasons for heterogeneity between the individual studies and analysed a dose-response-relationship using random effects mixed models. Results We identifi…
Meta-analysis of the relationship between teachers’ self-efficacy and attitudes toward inclusive education
2022
Abstract This meta-study aims to examine the size of the relationship between teachers' self-efficacy and attitudes toward inclusive education of K-12 students with special educational needs and to identify potential moderators (publication, sample, and research procedure characteristics). We synthesized the research conducted from 1994 to 2018, and 41 studies were included. Bare-bones meta-analysis with random effect model revealed a sample size weighted correlation coefficient between teachers’ self-efficacy and attitudes as r ¯ = 0.35 (CI = 0.31-0.39). The between-study variations were not associated with hypothesized publication and sample characteristics. However, the self-efficacy me…
Bayesian analysis and design for comparison of effect-sizes
2002
Comparison of effect-sizes, or more generally, of non-centrality parameters of non-central t distributions, is a common problem, especially in meta-analysis. The usual simplifying assumptions of either identical or non-related effect-sizes are often too restrictive to be appropriate. In this paper, the effect-sizes are modeled as random effects with t distributions. Bayesian hierarchical models are used both to design and analyze experiments. The main goal is to compare effect-sizes. Sample sizes are chosen so as to make accurate inferences about the difference of effect-sizes and also to convincingly solve the testing of equality of effect-sizes if such is the goal.