Invited Conference Speakers
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Medical Research Council Conference on Biostatistics in celebration of the MRC Biostatistics Unit's Centenary Year 24th - 26th March 2014 | Queens' College Cambridge, UK Invited Conference Speakers Professor Tony Ades, School of Social and Community Medicine, University of Bristol Tony Ades is Professor of Public Health Science at the University of Bristol and leads a programme on methods for evidence synthesis in epidemiology and decision modelling. This was originally funded through the MRC Health Services Research Collaboration. With Guobing Lu, Nicky Welton, Sofia DIas, Debbi Caldwell, Malcolm Price, Aicha Goubar and many collaborators in Cambridge and elsewhere, the programme has contributed original research on Network Meta- analysis, multi-parameter synthesis models for the epidemiology of HIV and chlamydia, synthesis for Markov models, expected value of information, and other topics. Tony was a member of the Appraisals Committee at the National Institute for Clinical Excellence (NICE), 2003-2013, and was awarded a lifetime achievement award in 2010 by the Society for Research Synthesis Methodology. Seminar Title: Synthesis of treatment effects, Mappings between outcomes, and test responsiveness Tuesday 25 March, 11.00-12.30 session Abstract: Synthesis of treatment effects, mappings between outcomes, standardisation, and test responsiveness AE Ades, Guobing Lu, Daphne Kounali. School of Social and Community Medicine, University of Bristol Abstract: We shall report on some experiments with a new class of models for synthesis of treatment effect evidence on “similar” outcomes, within and between trials. They are intended particularly for synthesis of patient- and clinician- reported outcomes that are subject to measurement error. These models assume that treatment effects on different outcomes are in fixed, or approximately fixed, ratios across trials. The task is therefore to estimate the pooled treatment effect on one of the outcomes, and “mapping coefficients” between the outcomes. We illustrate several uses of this model: for estimation of pooled effects, and estimation of “mappings” that are used in health economic analysis. We also show that it is an alternative to standardisation of treatment effects by dividing them by the sample standard deviation, and that it has superior properties. Finally, the models lead naturally to a meta-analytic account of the relative responsiveness of test instruments to treatment. Professor Per Kragh Andersen, Department of Biostatistics, Institute of Public Health, University of Copenhagen Per Kragh Andersen is Professor at the Department of Biostatistics. He took his Master's degree in 1978, a PhD degree in MathematicalS tatistics in 1982, and a Dr.Med.Sci. degree in 1997 - all from University of Copenhagen. Per’s main research interests are survival/event history analysis and analysis of cohort studies and other epidemiological applications of statistics. Seminar Title: Causal inference in survival analysis based on pseudo-observations Wednesday 26 March, 09.00-10.30 session Abstract: In causal inference for survival time outcomes the target is often taken to be the survival status at some time T (or maybe at a series of time points T_1, T_2,...). Since this is incompletely observed because of censoring standard approaches use inverse probability of censoring weighting. We will use another method and calculate pseudo- observations as outcome variables for each subject at T_1, T_2 etc. and then do an "ordinary complete data causal inference". Professor Nicky Best, GlaxoSmithKline Nicky Best recently joined GlaxoSmithKline as director of the new Statistical Innovation Group. Prior to this, she was Professor of Statistics & Epidemiology, School of Public Health, at Imperial College and Senior Investigator at the MRC- PHE Centre for Environment & Health, where her research focused on development and application of Bayesian methods in the health and social sciences. She is also a co-developer of the BUGS statistical software for Bayesian analysis. She was awarded the Royal Statistical Society Guy Medal in Bronze in 2004. Seminar Title: The BUGS Project: origins, challenges, and future directions Tuesday 25 March, 13.30-15.00 session Abstract: Abstract: BUGS is a software package for Bayesian inference using Gibbs sampling. The software has been instrumental in raising awareness of Bayesian modelling among both academic and commercial communities internationally, and has enjoyed considerable success over its almost 25 year life-span. In this talk we will present a brief overview of the BUGS project, illustrating some of the key evolutionary steps via the challenging applications that inspired them. Areas considered include disease mapping, prior elicitation, non-linear regression, model uncertainty, feedback control and evidence synthesis. Join us on twitter @MRC_BSU Medical Research Council Conference on Biostatistics in celebration of the MRC Biostatistics Unit's Centenary Year 24th - 26th March 2014 | Queens' College Cambridge, UK Dr Leonardo Bottolo, Faculty of Natural Sciences, Department of Mathematics, Imperial College London Leonardo Bottolo is a Lecturer in Statistics at Imperial College. He is interested in the application of Bayesian computational methods to exploit causes of genetic variation in final and intermediate phenotypes and their interaction, i.e. complex traits and transcriptional abundance respectively. His goal is to build a class of general purpose statistical tools that, together with portable, efficient and publicly available software solutions, can be used in the future to better understand the molecular mechanisms of disease pathogenesis. Seminar Title: Multivariate mixture priors for subgroups classification Tuesday 25 March, 15.30-17.00 session Abstract: Technologies for the collection of genetic data, such as those based on RNA-Seq, are developing at a very fast rate. A crucial objective in these studies is gene clustering based on the similarity of their level of expression. A more important clustering task concerns samples themselves: this goes under the name of molecular profiling, and aims at identifying similarities across samples based on a few genes identified from the previous stage of the analysis. In this talk we present a fully Bayesian hierarchical model for molecular profiling. A key ingredient of our approach is represented by the use of mixture distributions. First of all expression measurements are assumed to originate from a three-component mixture distribution, representing the underlying population classes (baseline, underexpression and overexpression) of samples relative to gene-expression. For each gene we assume a specific (random) probability of belonging to any of the three classes. Current Bayesian modelling assumes that the collection of gene-specific probabilities is exchangeable.Exchangeability assumption exhibits some drawbacks, the main one being its inability to capture heterogeneity in gene-behavior. This led us to model the gene-specific probabilities of under- overexpression using a multivariate mixture of prior distributions with an unknown number of components: this represents the novelty of our approach which is meant to capture variation in gene behaviour and to identify clusters of genes in relation to their probability of under and overexpression. The model is applied to gene expression levels from RNA-Seq analysis of left ventricular tissue derived from a cohort comprising 33 dilated cardiomyopathy patients with end-stage heart failure who underwent left ventricular assist device implant. Of these patients, 24 subsequently recovered their function whereas 9 did not. There is no obvious distinguishing features between them at the time the sample was taken. Molecular profiling is derived to predict recovery vs non-recovery patients. This is a joint work with Petros Dellaportas and Athanassios Petralias, Dept of Statistics, Athens University. Professor Norman Breslow, Department of Biostatistics, University of Washington Emeritus Professor and former Chairman of the Department of Biostatistics at the University of Washington. Member of the Biostatistics Program, Division of Public Health Sciences, Fred Hutchinson Cancer Research Center. He was awarded the Mortimer Spiegelman Award of the American Public Health Association (1978), the Senior U.S. Scientist Award of the Alexander von Humboldt Foundation (1982-83), the 1995 George W. Snedecor Award of the Committee of Presidents of Statistical Societies (COPSS), the 1995 R.A. Fisher Award of COPSS, the 1998 Statistician of the Year awarded by the Chicago Chapter of the American Statistical Association, Docteur Honoris Causa from Bordeaux (2001), the Nathan Mantel Award, Section on Statistics in Epidemiology of the American Statistical Association (2002), was elected Honorary Fellow of the Royal Statistical Society (1994) and was elected member of the Institute of Medicine of the National Academy of Science. Professor Breslow has made pioneering contributions to the advancement of biostatistical methodological developments in survival analysis, generalized linear mixed models and the design of case-control and cohort studies. He has made instrumental contributions in cancer epidemiology and is a founding member of the National Wilms' Tumor Study Committee. He is co-author of the influential textbooks, Statistical Methods in Cancer Research (vols. I & II), with Nicholas E. Day. Seminar Title: Using the Whole Cohort in the Analysis of Case-Control Data: Applications