Evidence-based Health Economics: From effectiveness to efficiency in systematic review Edited by Cam Donaldson Svare Chair in Health Economics, University of Calgary Miranda Mugford Professor of Health Economics, University of East Anglia Luke Vale Research Fellow, University of Aberdeen BMJ Books 2002 BMJ Books is an imprint of the BMJ Publishing Group All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording and/or otherwise, without the prior written permission of the publishers. First published in 2002 by BMJ Books, BMA House, Tavistock Square, London WC1H 9JR www.bmjbooks.com British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN 0 7279 1579 7 Typeset by SIVA Math Setters, Chennai, India Printed and bound in Spain by GraphyCems, Navarra Contents Contributors v Preface vii 1 From effectiveness to efficiency: an introduction to evidence-based health economics 1 Cam Donaldson, Miranda Mugford, Luke Vale 2 Using systematic reviews in economic evaluation: the basic principles 10 Cam Donaldson, Miranda Mugford, Luke Vale 3 Reviewing economic evidence alongside systematic reviews of effectiveness: example of neonatal exogenous surfactant 25 Miranda Mugford 4 The place of economic analyses in systematic reviews: a clinician’s viewpoint 38 Cindy Farquhar, Paul Brown 5 Evidence-based economic evaluation: how the use of different data sources can impact results 55 Douglas Coyle, Karen M Lee 6 Methodological quality of economic evaluations of health care interventions – evidence from systematic reviews 67 Tom Jefferson, Luke Vale, Vittorio Demicheli 7 Effectiveness estimates in economic evaluation 89 Vittorio Demicheli, Tom Jefferson, Luke Vale 8 Criteria list for conducting systematic reviews based on economic evaluation studies – the (cid:1) CHEC project 99 Andre Ament, Silvia Evers, Marielle Goossens, Henrica de Vet, Maurits van Tulder 9 Evaluating economic interventions: a role for non-randomised designs? 114 Ivar Sønbø Kristiansen, Toby Gosden iii CONTENTS 10 Making the problem fit the solution: evidence-based decision making and “Dolly” economics 133 Stephen Birch 11 Evidence-based medicine meets economic evaluation – an agenda for research 148 Michael Drummond 12 Glossary of terms for health economics and systematic review 155 Gillian Currie, Braden Manns Index 163 iv Contributors * denotes attendance at the Banff Workshop Andre Ament* Associate Professor in Health Economics, Department of Health Organisation Policy and Economics, Faculty of Health Sciences, Maastricht University, Netherlands Stephen Birch* Professor of Health Economics, Centre for Health Economics and Policy Analysis, McMaster University, Hamilton, Ontario, Canada Paul Brown Senior Lecturer in Health Economics, Department of Community Health, University of Auckland, New Zealand Douglas Coyle* Assistant Professor of Health Economics, Clinical Epidemiology Unit, Ottawa Health Research Institute, Ottawa Hospital; Departments of Medicine and Epidemiology and Community Medicine, University of Ottawa, Ontario, Canada Gillian Currie* Assistant Professor of Economics, and Alberta Heritage Population Health Investigator, Departments of Economics and Community Health Sciences, University of Calgary; Fellow, Institute of Health Economics, Alberta, Canada Vittorio Demicheli Cochrane Collaboration and Servizio Epidemiologia ASL 20, Alessandria, Italy Henrica de Vet Associate Professor in Epidemiology, Institute for Research in Extramural Medicine, VU University Medical Centre, Amsterdam, Netherlands Cam Donaldson* Svare Chair in Health Economics and Canadian Institutes of Health Research Senior Investigator, Departments of Community Health Sciences and Economics, University of Calgary; Fellow, Institute of Health Economics, Calgary, Alberta, Canada Michael Drummond* Professor of Health Economics and Director, Centre for Health Economics, University of York, UK Silvia Evers Postdoctoral Research Affiliate, Department of Health Organisation Policy and Economics, Faculty of Health Sciences, Maastricht University, Netherlands v CONTRIBUTORS Cindy Farquhar* Associate Professor in Reproductive Medicine, Cochrane Menstrual Disorders and Subfertility Group, National Women’s Hospital, University of Auckland, New Zealand Marielle Goossens Postdoctoral Research Affiliate, Institute for Rehabilitation Research, Hoensbroek and Maastricht University, Netherlands Toby Gosden* Research Fellow, National Primary Care Research and Development Centre, University of Manchester, UK Tom Jefferson* Cochrane Collaboration and Health Reviews Ltd, Rome, Italy Ivar Sønbø Kristiansen* Associate Professor of Community Medicine, Institute of Public Health – Health Economics, University of Southern Denmark, Odense, Denmark Karen M Lee Caro Research, Boston, Massachusetts, USA Braden Manns* Assistant Professor of Medicine, Departments of Medicine and Community Health Sciences, University of Calgary; Fellow, Institute of Health Economics, Alberta, Canada Miranda Mugford* Professor of Health Economics, School of Medicine, Health Policy and Practice, University of East Anglia, Norwich, UK Luke Vale* Research Fellow, Health Economics Research Unit and Health Services Research Unit, University of Aberdeen, UK Maurits van TulderEpidemiologist, Senior Investigator HTA, Institute for Research in Extramural Medicine and Department of Clinical Epidemiology and Biostatistics, VU University Medical Centre, Amsterdam, Netherlands vi Preface Decision makers, when weighing up evidence, have to consider information produced from health economics, evidence-based medicine and systematic reviews. Despite their importance, these three sources of information are rarely considered together. One attempt to do so was the formation of the Economics Methods Group within the Cochrane Collaboration in 1998. The Cochrane Economics Methods Group (CEMG) aims to • Develop and disseminate methods for reviewing trials, and other studies, with economic elements, and for building economic evaluations from reviews of effectiveness. • Be a discussion and methods development group for economists involved with Cochrane Reviews, to encourage transparency of methods and liaison with other methods groups on topics of common interest. • Provide links for Cochrane Review Groups with health economists and other sources. • Run workshops and discussions on economic issues and methods relevant to the aims of the Cochrane Collaboration. Much of the work of the CEMG over the past three years has been in encouraging the collaboration of health economists and systematic reviewers. Many such joint ventures also take place outwith the auspices of the Cochrane Collaboration. It is important, therefore, to summarise the “state of the art” on how studies involving such collaborations are conducted. However, to improve such studies in the future, further research has to be carried out. This book attempts to provide the reader with the underlying principles, along with case studies, of how to use systematic review data in economic evaluations. In doing this, it will be seen that different approaches can be used, each of which provides different results. This, in itself, sets an agenda for future research, to identify whether there is a best method, and, if so, what it is. The volume also provides challenges to the current evidence-based medicine paradigm, which permits us to rethink our overall approach to the use of evidence and economics in health policy making, and, again, provides us with food for future research. The chapters in the book were initially presented as papers at a workshop, held at the Banff Centre for Continuing Education, Alberta, Canada in vii PREFACE February 2001. We would like to acknowledge the support, financial and otherwise, for this workshop provided by the Institute of Health Economics and its Chief Executive Officer, Dev Menon. We would also like to acknowledge the support of Mary Banks from BMJ Books, and Lindsay Bradshaw and Diane Lorenzetti of the University of Calgary for organising the production of the material. Many unnamed colleagues have contributed informally through comments on drafts or discussions, and we thank them all. All three editors and other contributors acknowledge the support of their home institutions and funding bodies. We also thank Elsevier Science Ltd for permission to reproduce Figure 1.1. Having mapped out current approaches and future directions for research, we hope that the book provides an exciting agenda for research and collaboration in this important area over the coming years. Cam Donaldson Miranda Mugford Luke Vale Co-convenors, Cochrane Economics Methods Group viii 1: From effectiveness to efficiency: an introduction to evidence-based health economics CAM DONALDSON, MIRANDA MUGFORD, LUKE VALE Introduction Evidence-based medicine (EBM) has become synonymous with the notion of systematic reviews. Such systematic reviews attempt to assemble data, from published and unpublished sources, on the effectiveness of health care interventions. The aim has been to inform clinical practice and, of course, to change practice where patient and public health can be improved. However, evidence-based practice isolated from economic issues is not realistic, and, indeed, may ultimately harm patients and the public. More fundamentally, narrow evidence-based medicine methodologies may themselves contribute to inefficient health policy and greater inequalities in health. Evidence-based health economics recognises not only the need for the use of evidence-based principles in economic evaluation but also that such principles should themselves be based on economics concepts. Therefore, in this book, the intention is to: • discuss the role of systematic reviews in economic evaluations of health care; • provide case studies to demonstrate how systematic reviews can be used in economic evaluations; and • show the limitations of current evidence-based approaches and how economics can be used to improve and broaden the evidence base in ways that are more relevant for policy makers. 1 EVIDENCE-BASED HEALTH ECONOMICS In this introductory chapter, it is important to consider, first, the importance of economics to systematic review. This is reinforced by reflecting on the views of two of the founding fathers of evidence-based medicine and health economics – Archie Cochrane and Alan Williams. The chapter goes on from there to outline the limitations of evidence-based medicine and a health economics approach built on such foundations, and introduce a conceptual framework for the book. This introduction is illustrated with examples of policy questions that can be addressed by an evidence-based health economics approach. Finally, the contents of the book are outlined in more detail. The importance of economics in systematic review The main purpose of systematic reviews of health care interventions has been seen as providing information about the effectiveness of these interventions.1Typically, systematic reviews in EBM are designed to test a hypothesis as to whether a new form of health care is or is not more effective than an alternative, using dichotomous measures, via odds ratios or relative risks, rather than continuous measures, such as effect size. These reviews are not usually designed to ask the question “how much more effective is the new form of care”. The issue of how to estimate effect size is central to Chapter 5, by Coyle and Lee. In order to judge how to act on the evidence from systematic reviews in the face of scarce resources, decision makers need to consider further evidence. Nearly every health care intervention has an impact not only on health and social welfare but also on the resources used in the production of care. As resources have alternative beneficial uses and as different people may place different values on the various health outcomes, then, to make the best decisions about alternative courses of action, information is needed on the health benefits and also the extent of resource use (or cost) of these courses of action. The need to assess the “economic” gain from alternative forms of care is reflected in the continuing development of economic evaluation methods and the increasing numbers of studies with health economic input. Compilers of clinical practice guidelines are also placing more emphasis on economic data.2 Economic evaluations of interventions are central to informing the advice and decisions issued by organisations such as the UK’s National Institute for Clinical Excellence (NICE) and the Australian Government’s Pharmaceutical Benefits Advisory Committee (PBAC). That is, these organisations are concerned with issues of cost-effectiveness and cost-benefit. When addressing such issues, the types of policy question that can be addressed are: 2