Acknowledgments IT IS A PLEASURE AND A PRIVILEGE TO THANK EACH AND ALL INDIVIDUALS throughout the world who volunteered to contribute terms, definitions, or other ideas for this dictionary: never before had I enjoyed such a large, diverse, and creative group of coauthors. Thanks! I trust you will understand that I could not always make all your scientific, linguistic, and lexicographic dreams come true. And I very much hope you will have fun skimming through the pages that follow It is equally a joy and an honor to thank all members of the International Epidemiological Association(IEA), and in their name, especially, past, current or coming presidents Rodolfo Saracci, Charles du VFlorey, Chitr Sitthi-Amorn, Jorn Olsen, and Neil Pearce for their intellectual stimulus, personal encouragement, and institutional support in editing this book. I feel extremely fortunate that Sander Greenland and John Last accepted my personal invitation to work as associate editors and that they offered extremely valuable contributions: I am sure that readers-some, perhaps unknowingly-will be equally fortunate: a lot in this volume is due to John and Sander. It is also my great pleasure to give special thanks to Miguel A practical contributions, many made speedily and when it seemed impossible to achieve clarity for particularly complex or unusual terms. For what I have made of the advice of all contributors, and for any errors, I alone am spons Warm thanks are also due to the linguistic and lexicographic consultants, Janet Byron Anderson(fourth edition), Lluis Quintana, Albert Rico and David J. MacFarlane (fifth edition). Skilled editorial assistance was kindly and efficiently provided by Joan Pau Millet, Eva Morales, Tomas Lopez and Silvia geeraerd This edition was prepared with support from an unrestricted grant fre Esteve Foundation(Barcelona, Catalonia, Spain), a nonprofit, internationally focusedinstitution with the primary goal of fostering progress in pharmacotherapy Some operational costs were absorbed in our budget at the Institut Municipal d'Investigacio Medica(IMIM) and at the Universitat Autonoma de barcelona, for which I am also grateful
It is a pleasure and a privilege to thank each and all individuals throughout the world who volunteered to contribute terms, defi nitions, or other ideas for this dictionary: never before had I enjoyed such a large, diverse, and creative group of coauthors. Thanks! I trust you will understand that I could not always make all your scientifi c, linguistic, and lexicographic dreams come true. And I very much hope you will have fun skimming through the pages that follow. It is equally a joy and an honor to thank all members of the International Epidemiological Association (IEA), and in their name, especially, past, current or coming presidents Rodolfo Saracci, Charles du V. Florey, Chitr Sitthi-Amorn, Jørn Olsen, and Neil Pearce for their intellectual stimulus, personal encouragement, and institutional support in editing this book. I feel extremely fortunate that Sander Greenland and John Last accepted my personal invitation to work as associate editors and that they offered extremely valuable contributions; I am sure that readers—some, perhaps unknowingly—will be equally fortunate: a lot in this volume is due to John and Sander. It is also my great pleasure to give special thanks to Miguel A. Hernán and Vasily Vlassov for their extremely thoughtful, insightful, and practical contributions, many made speedily and when it seemed impossible to achieve clarity for particularly complex or unusual terms. For what I have made of the advice of all contributors, and for any errors, I alone am responsible. Warm thanks are also due to the linguistic and lexicographic consultants, Janet Byron Anderson (fourth edition), Lluís Quintana, Albert Rico and David J. MacFarlane (fi fth edition). Skilled editorial assistance was kindly and effi ciently provided by Joan Pau Millet, Eva Morales, Tomas Lopez and Silvia Geeraerd. This edition was prepared with support from an unrestricted grant from the Esteve Foundation (Barcelona, Catalonia, Spain), a nonprofi t, internationally focused institution with the primary goal of fostering progress in pharmacotherapy. Some operational costs were absorbed in our budget at the Institut Municipal d’Investigació Mèdica (IMIM) and at the Universitat Autònoma de Barcelona, for which I am also grateful. Acknowledgments xv
Acknowledgments ike many other human beings for centuries, I continue to treasure my love-both emotional and practical-for books, and have come to experience a somewhat peculiar bliss in reading prophecies on the death of the book. I am, therefore, so glad to acknowledge everyone at Oxford University Press, who with their outstanding editorial competence and wisdom also made this book. I dedicate it to the youngest generation of health scientists and advocates; and to anna julia and Joan
Like many other human beings for centuries, I continue to treasure my love—both emotional and practical—for books, and have come to experience a somewhat peculiar bliss in reading prophecies on the death of the book. I am, therefore, so glad to acknowledge everyone at Oxford University Press, who with their outstanding editorial competence and wisdom also made this book. I dedicate it to the youngest generation of health scientists and advocates; and to Anna, Júlia, and Joan. M. P. Acknowledgments xvi
About This Dictionary Advice on how best to use it) Alphabetical Listing The alphabetical listing is a guide to the placement of entries and follows a letter-by-letter sequence of headwords without regard to word spacing, hyphens, or apostrophes. For example Case classification Case-control study Case finding Case-only study Case-specular design Case-time-control design Headwords Headwords are in bold small capitals. If there are several varieties of a concept such as bias, all are listed alphabetically under the headword BIAs; but when customary epidemiological usage places an adjective before the headword, the alphabetical listing is usually a cross-reference to the entry where the definition is to be found. Thus BIAS, CONFOUNDING leads the user to the definition under CONFOUNDING BIAS. However, terms on the periphery of epidemiology are mostly located together under the pertinent headword. For example, most of those associated with costs appear under cosT. Compound phrases Epidemiology has many compound phrases, not all of which have an obvious headword. Thus rare disease assumption is found under RARE, not under disease. Citations In this edition all citations of articles and books have been moved to the back of the book (See pages 273-289). This allo petition-some books and articles are cited several times. Most citations are just meant to help the reader follow-up on the definition; they just aim to evoke or suggest further avenues of thought. They cannot be and are not exhaustive. None is meant to endorse the definition or the comment. No citation is meant either to imply that an article or book is the original or most authoritative source on the issue. Many cited books will provide additional help on additional terms, that is, in definitions where they are not cited; this is particularly the case for definitions of terms on epidemiological methods
Alphabetical Listing The alphabetical listing is a guide to the placement of entries and follows a letter-by-letter sequence of headwords without regard to word spacing, hyphens, or apostrophes. For example: Case classifi cation Case-control study Case fi nding Case-only study Case-specular design Case-time-control design Headwords Headwords are in bold small capitals. If there are several varieties of a concept, such as bias, all are listed alphabetically under the headword BIAS; but when customary epidemiological usage places an adjective before the headword, the alphabetical listing is usually a cross-reference to the entry where the defi nition is to be found. Thus BIAS, CONFOUNDING leads the user to the defi nition under CONFOUNDING BIAS. However, terms on the periphery of epidemiology are mostly located together under the pertinent headword. For example, most of those associated with costs appear under COST. Compound Phrases Epidemiology has many compound phrases, not all of which have an obvious headword. Thus rare disease assumption is found under RARE, not under disease. Citations In this edition all citations of articles and books have been moved to the back of the book (See pages 273–289). This allowed us to avoid repetition—some books and articles are cited several times. Most citations are just meant to help the reader follow-up on the defi nition; they just aim to evoke or suggest further avenues of thought. They cannot be and are not exhaustive. None is meant to endorse the defi nition or the comment. No citation is meant either to imply that an article or book is the original or most authoritative source on the issue. Many cited books will provide additional help on additional terms, that is, in defi nitions where they are not cited; this is particularly the case for defi nitions of terms on epidemiological methods. About This Dictionary (Advice on how best to use it) xvii
About this dictionary Acronyms There is no generally agreed way to pronounce or print acronyms, but some usages are commonly agreed. Thus, for instance, WHO is always spelled out In pronunciation(WHO”), never pronounced“Hoo.” By contrast,AIDS is always pronounced"Aids"and never spelled out. Acronyms can be made up of the initial letters of the words on which they are based, such as NIOSH (National Institute for Occupational Safety and Health, pronounced Ny-osh) or on parts of words or abbreviations, such as QUANGo(quasi-autonomous nongovernmental organization). Acronyms can survive after the organization they signify has changed names. UNICEF originally stood for United Nations International Children's Emergency Fund. This UN agency is now called the United Nations Children's Fund, but the acronym is unchanged. Generally, all the letters of an acronym are upper case, even when not all the letters are initial letters of individual words, So ANOVA, analysis of variance, is spelled as here, not AnoVa, although Anova is sometimes seen Cross-References Most cross-references identified in the text of the definitions are in nonbold small capitals. Other important words and phrases mentioned in a definition are sometimes italicized to draw attention to their special significance in relation to that particular term and to signify the absence of a cross-reference Cross references are again just meant to suggest-to invite the reader to take a look elsewhere in the book. They are not exhaustive: a term may appear in another art of the book and yet not be marked in nonbold small capitals(one common reason for that is to avoid a baroque or visually confusing sentence) Definitions and discussions a brief definition generally appears at the beginning of each entry. This usually follows dictionary conventions and is a statement of the meaning rather than an explanation. However, there are many discussions and, occasionally, illustrative examples and remarks on the provenance of terms. Admonitions and cautionary notes about use and abuse of terms have been kept to a minimum. Evolving Language and Changing Usage English and its technical varieties are evolving and changing, as do virtually all societies worldwide--and foremost the Internet and the virtual society. We aimed at sensibly respecting all sensitivities, and we found no major difficulties in doing so while at the same time ensuring precision and avoiding ambiguity in scientific communication Epidemiology is expanding and budding off subspecialties, each of which has its own vocabulary, terms, and meanings, adapting old words and phrases to new uses,creating its own neologisms. Epidemiology regularly absorbs, transforms, and embodies terms from other fields: as a living organism, it actively metabolizes
Acronyms There is no generally agreed way to pronounce or print acronyms, but some usages are commonly agreed. Thus, for instance, WHO is always spelled out in pronunciation (“W-H-O”), never pronounced “Hoo.” By contrast, AIDS is always pronounced “Aids” and never spelled out. Acronyms can be made up of the initial letters of the words on which they are based, such as NIOSH (National Institute for Occupational Safety and Health, pronounced Ny-osh), or on parts of words or abbreviations, such as QUANGO (quasi-autonomous nongovernmental organization). Acronyms can survive after the organization they signify has changed names. UNICEF originally stood for United Nations International Children’s Emergency Fund. This UN agency is now called the United Nations Children’s Fund, but the acronym is unchanged. Generally, all the letters of an acronym are upper case, even when not all the letters are initial letters of individual words, so ANOVA, analysis of variance, is spelled as here, not AnOVa, although Anova is sometimes seen. Cross-References Most cross-references identifi ed in the text of the defi nitions are in nonbold small capitals. Other important words and phrases mentioned in a defi nition are sometimes italicized to draw attention to their special signifi cance in relation to that particular term and to signify the absence of a cross-reference. Crossreferences are again just meant to suggest—to invite the reader to take a look elsewhere in the book. They are not exhaustive; a term may appear in another part of the book and yet not be marked in nonbold small capitals (one common reason for that is to avoid a baroque or visually confusing sentence). Defi nitions and Discussions A brief defi nition generally appears at the beginning of each entry. This usually follows dictionary conventions and is a statement of the meaning rather than an explanation. However, there are many discussions and, occasionally, illustrative examples and remarks on the provenance of terms. Admonitions and cautionary notes about use and abuse of terms have been kept to a minimum. Evolving Language and Changing Usage English and its technical varieties are evolving and changing, as do virtually all societies worldwide—and foremost the Internet and the virtual society. We aimed at sensibly respecting all sensitivities, and we found no major diffi culties in doing so while at the same time ensuring precision and avoiding ambiguity in scientifi c communication. Epidemiology is expanding and budding off subspecialties, each of which has its own vocabulary, terms, and meanings, adapting old words and phrases to new uses, creating its own neologisms. Epidemiology regularly absorbs, transforms, and embodies terms from other fi elds: as a living organism, it actively metabolizes About this dictionary xviii
About this dictionary anguage. We have tried to capture and present the essential terminology of clinical, environmental, genetic, social, and molecular epidemiology as well as core terms from pediatric epidemiology, pharmaco-epidemiology, and some other subspecialties of epidemiology. Of course, we did not wish to lengthen the book too much. Thus, the reader will sometimes need to go to the specialty books in seeking definitions of highly specialized terms. Finally, some common everyday words are defined and discussed because they often occur in epidemiological articles with a distinct meaning, they are particularly relevant to conduct health research, or because their sense is not always clear in these contexts to people hose first language is not English. Words and phrases from disciplines that overlap or interact with epidemiology are defined here for the same reasons. We have tried to be highly rigorous, systematic, thorough, and to a reasonable extent, explicit and transparent; yet when necessary, these goals gave precedence to the primary objective: that the dictionary should be practical and plural, and that it should encourage critical and creative thinking M. P andoM.L
language. We have tried to capture and present the essential terminology of clinical, environmental, genetic, social, and molecular epidemiology as well as core terms from pediatric epidemiology, pharmaco-epidemiology, and some other subspecialties of epidemiology. Of course, we did not wish to lengthen the book too much. Thus, the reader will sometimes need to go to the specialty books in seeking defi nitions of highly specialized terms. Finally, some common everyday words are defi ned and discussed because they often occur in epidemiological articles with a distinct meaning, they are particularly relevant to conduct health research, or because their sense is not always clear in these contexts to people whose fi rst language is not English. Words and phrases from disciplines that overlap or interact with epidemiology are defi ned here for the same reasons. We have tried to be highly rigorous, systematic, thorough, and to a reasonable extent, explicit and transparent; yet when necessary, these goals gave precedence to the primary objective: that the dictionary should be practical and plural, and that it should encourage critical and creative thinking. M. P. and J. M. L. xix About this dictionary