Epidemiological Research O.S. Miettinen • I. Karp Epidemiological Research: An Introduction 123 O.S. Miettinen I. Karp McGill University UniversitedeMontr´ eal´ UniversitedeMontr´ eal´ Montreal,´ QC Montreal,´ QC Canada Canada Cornell University New York, NY USA ISBN 978-94-007-4536-0 ISBN 978-94-007-4537-7 (eBook) DOI 10.1007/978-94-007-4537-7 Springer Dordrecht Heidelberg New York London Library of Congress Control Number: 2012942327 ©SpringerScience+BusinessMediaDordrecht2012 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. 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Printed on acid-free paper Springer is part of SpringerScience+BusinessMedia(www.springer.com) Foreword ‘In my life ever since medical-school graduation half-a-century ago, I’ve had the dream of reaching true understanding of the theory of the research that would best serve to advance the knowledge-base of medicine, of genuinely scientific medicine.’ Olli Miettinen wrote this a year or so ago in his Epidemiological Research: Terms and Concepts.Forthosewhohavehadtheprivilegetowitnesshisodysseysince the 1970s, the current book comes as both a wonderful revisit of the past and agreatleapintothefuture.Miettinen’stextaccompanyinghiscourseinthe 1970s at Harvard was ‘the first systematic introduction to theoretical epidemiology’ (Greenland) and can be viewed as the start of ‘modern epidemiology’ (Morabia). But he never published it and therefore the book that you read now is the first published introduction to epidemiological research by the father and grand master of modern epidemiology. Epidemiological Research: An Introduction,thecurrentbookofMiettinen, in collaboration with his junior colleague Igor Karp, is a true milestone for epidemiology, but a cautionary word may be in place about the ‘introduction.’ I remember Miettinen referring to his courses as basic, but not basal. The current book, similarly, is basic, but not basal. It is introductory in that it develops the objects and methods of epidemiological research from first principles, but it does so in a breathtakingly sophisticated way, alternatingly grand and subtle in argumentation, visionary and down-to-earth, broad and deep.Forthisreaderonethingisparticularly clear: Miettinen’s discussion is still unparalleled in our field, the logic and coherence is as spellbinding as ever (and I need to think a bit more, and better, if and when I do not fully understand what he writes). The structure of this book must be a treat for all epidemiologists. From ‘epidemi- ology: grappling with the concept’ through ‘etiology as a pragmatic concern’ and the ‘object of study’ to the book’s core on ‘objects design’ and ‘methods design,’ it is like travelling to familiar destinations along new roads. Although Miettinen has always stressed the importance of objects design from first principles, I think this book is the first to treat this topic systematically and somewhat extensively. And although Miettinen has published quite comprehensively on the fallacies in the v vi Foreword design of epidemiological studies and their remedies, I find his discussion of ‘the etiologic study’ fresh and summarized aptly and succinctly in ‘e pluribus unum’ and ‘e unum pluribus.’ What will be the effect on the practice of epidemiological research? I have no doubt that it will be vast, but also that it will be slow to come. In the long run, his arguments will turn out to be irresistible, although most likely modified and expanded. It is like the effect of epidemiological research on medical practice: it is hardly ever direct, it nearly always takes a long time, but in the end it makes a true core contribution. Ipaytributetothefatherofmodernepidemiology,andrecommendthisvolume to assist in deep epidemiological introspection. It will benefit epidemiology and epidemiologists greatly. Albert Hofman, M.D., Ph.D., Professor and Chair, Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands. Preface Anyone conducting epidemiological research is prone to encounter obvious major challenges of a conceptual nature, sometimes seeing them to be tauntingly complex, at other times subtle beyond concrete grasp. But the challenges can also remain unrecognized and thereby unmet, ones ofmajorconsequenceincluded. Even when no longer a beginner in the research, the investigator may wonder about the adequacy of the copings with these challenges, notably when considering how controversial many of even the much-researched substantive issues remain and, thus, how little consequence the research – his/her own and that of others too – is having in the evolution of knowledge-based societal policies about healthcare and in the advancement of public-health practices within their respective policy frameworks. The key to attaining, and maintaining, the conceptual understandings that form the basis for maximally consequential careers in epidemiological research we take to be suitable introduction to – and thereby the attainment of a wholesome outlook in – such research. To this end, authors of introductory textbooks on the research need to try to present basic ideas that are so obviously well-focused and so obviously tenable that they thereby get to be – even where they aren’t yet – commonly agreed upon by the teachers as properly constituting the core content of an introductory course on the research. In our view, an introductory course on epidemiological research should bring to focus, and give tenable answers to, such orientational, normative questions as: To what pragmatic ends should the research be conducted? What, as for both substance and form, should the population-level research be about? What should be understood to be the necessary, logical nature of those studies themselves on the principal generic types of object of study? What are the main concerns and principles in the optimization of the objects and methods of those studies? and How should the evidence from the studies be transmuted into knowledge about the respective objects of study? We here make a serious effort, our first, to formulate answers to these, and related, questions for possible incorporation into teachers’ efforts to properly introduce their students to the research – specifically, as insinuated above, to vii viii Preface epidemiological research that would be maximally consequential and hence per- sonally most gratifying to them, with society at large not only the sponsor but also the correspondingly, if not even more richly, rewarded beneficiary of it. In this effort we are guided by our belief that a proper introductory course on epidemiological research, like its counterpart on physics for example, conveys the most advanced insights into the most elementary –themostappropriatelychosento be the most elementary – component topics within the overall topic; and our aim is to introduce them in a logical sequence,formostnaturalandeffectivestudybythe students. A contemporary introductory course on physics teaches, for example, that the formerly common idea of ether as a ubiquitous medium for electric and magnetic forces (alaMaxwell’sequations)isnowseentohavebeenamisunderstanding;and` asuitablyadvancedintroductorycourseonepidemiological research now teaches, for example, that the still-common concepts of cohort study and case-control study should already be passe.´ There is a story (apocryphal) about the physicist Niels Bohr and the philosopher Bertrand Russell concerning their respective decisions not to study psychology in preparation for a career in it, about their respective decisions to study mathematics- cum-physics and mathematics-cum-philosophyinstead. Bohr is said to have rejected the psychology option on the ground that this field is too easy, and Russell on the ground that it is too difficult, to gain mastery of. We are of the view that preparation for a productive and thereby gratifying career in epidemiological research – different from a stellar career in quantum physics or theoretical philosophy