17/12/2002 CHEBS Launch Seminar CHEBS Activities and Plans Tony O’Hagan Director

17/12/2002CHEBS Launch Seminar What is CHEBS? An official interdisciplinary research centre of the University of Sheffield A collaboration that builds on a unique combination of strengths ›Bayesian Statistics – Department of Probability and Statistics ›Health Economics – ScHARR ›Operational Research – ScHARR

17/12/2002CHEBS Launch Seminar CHEBS’ Mission To engage in innovative research, developing methodology based on Bayesian statistics for solution of problems in health economics To set standards for statistical analysis of health economic data and models To promote dialogue with the pharmaceutical industry, including consultancy and training To influence best practice in presentation of health economic information to regulators and health care providers

17/12/2002CHEBS Launch Seminar CHEBS Activities Primary research ›CHEBS Research Fellow Focus Fortnights ›Invited visiting experts ›Dissemination workshop ›Strategic research themes »Evidence Synthesis »Value of Information »Elicitation »Costs …

17/12/2002CHEBS Launch Seminar Short courses Research contracts, participating in: ›Department of Health – Multiple Sclerosis ›NICE – Decision Support Unit

17/12/2002CHEBS Launch Seminar CHEBS Base Funding Base funding from sponsors ›pays for Research Fellows, Focus Fortnights, administrative costs, etc. Ensures academic freedom ›informed by needs of sponsors and other stakeholders Sponsors benefit from ›briefings and seminars, ›access to a unique blend of expertise

17/12/2002CHEBS Launch Seminar Bayesian Statistics in Health Economics Some research areas: Trial design and analysis Modelling costs Quantifying uncertainty & evidence synthesis Outcomes – QoL estimation and uncertainty Sensitivity and VoI analysis of economic models

17/12/2002CHEBS Launch Seminar Trial design and analysis Design ›Must use prior information! ›More rational design criteria ›Sequential design Analysis ›Can use prior information ›More accurate modelling ›More interpretable inferences

17/12/2002CHEBS Launch Seminar Modelling costs Cost distributions are highly skew Sample sizes are often small Conventional robust methods … ›Normal distributions ›Bootstrapping … are criterion robust but not inference robust ›Sample means are inefficient and sensitive to outliers Tails matter

17/12/2002CHEBS Launch Seminar Quantifying uncertainty & evidence synthesis Uncertainty has many sources Only Bayesian methods can quantify and account for all kinds of uncertainty ›Randomness ›Lack of knowledge Synthesising evidence from diverse sources requires careful consideration of uncertainties ›Bayesian analysis of primary data feeds into economic models

17/12/2002CHEBS Launch Seminar Outcomes Utilities ›Bayesian methods can better estimate utility functions from raw preference data ›Uncertainty in the estimated utilities can be quantified

17/12/2002CHEBS Launch Seminar Sensitivity & VoI analyses Sensitivity analysis ›Parameter distributions intrinsically Bayesian »Evidence synthesis ›Efficient propagation of uncertainty through models ›Detailed analysis of sensitivity to individual parameters or groups of parameters ›Value of information analysis »EVPI »EVSI

17/12/2002CHEBS Launch Seminar The future is Bayesian Demand for Bayesian methods is increasing at a spectacular rate Driven by … conceptual advantages ›Bayesian inferences answer the question … practical advantages ›Able to use all available information … computational advantages ›Able to tackle more complex models and data

17/12/2002CHEBS Launch Seminar This is happening in many fields ›Specially in younger disciplines like health economics Barriers to acceptance are crumbling ›Regulators increasingly open to Bayesian methods ›Bayes has achieved academic respectability Inertia is still a problem! Remaining barriers are being addressed ›Lack of software is a damper on take-up ›Clearer guidelines are needed on priors

17/12/2002CHEBS Launch Seminar The future is multidisciplinary Many skills must come together ›Statistics ›Economics ›Modelling/OR ›Decision analysis ›Clinical/pharmaceutical/… ›Sociology/psychology

17/12/2002CHEBS Launch Seminar Many stakeholders’ interests must be recognised ›Patients ›Industry ›Practitioners ›Taxpayers