Therearemanygoodepidemiologytextbooksonthemarket,butmostoftheseare addressedtostudentsofpublichealthorpeoplewhodoclinicalresearchwithe- demiologicmethods. Thereisaneedforashortintroductiononhowepidemiologic methodsareusedinpublichealth,geneticandclinicalepidemiology,becausehealth professionalsneedtoknowbasicepidemiologicmethodscoveringetiologicaswell asprognosticfactorsofdiseases. Theyneedtoknowmoreaboutmethodologythan introductorytextsonpublichealthhavetooffer. Insomehealthfaculties,epidemiologyisnotevenpartoftheteachingcurri- lum. Webelievethistobeaseriousmistake. Medicalstudentsarestudentsofall aspectsofdiseasesandhealth. Withoutknowingsomethingaboutepidemiologythe cliniciansandotherhealthprofessionalscannotreadagrowingpartofthesci- ti cliteratureinanyreasonablycriticalwayandcannotnavigateintheworldof "evidence-basedmedicineandevidence-basedprevention. "Withoutskillsine- demiologicmethodologytheyareinthehandsofexpertsthatmaynotonlyhavean interestinhealth. Some health professionals may believe that only common sense is needed to conductepidemiologicalstudies,butthescienti cliteratureandthepublicdebate onhealthissuesindicatethatcommonsenseisofteninshortsupplyandmaynot thrivewithoutsomeformaltraining. Epidemiologic methods play a key role in identifying environmental, social, and genetic determinants of diseases. Clinical epidemiology addresses the tr- sitionfromdiseasetohealthortowardmortalityorsocialormedicalhandicaps. Publichealthepidemiologyaddressesthetransitionfrombeinghealthytobeingnot healthy. Descriptiveepidemiologyprovidesthediseasepatternthatisneededtolook athealthinabroadperspectiveandtosettheprioritiesright. Epidemiologyisabasic scienceofmedicinewhichaddresseskeyquestionssuchas"Whobecomesill?"and "Whatareimportantprognosticfactors?"Answerstosuchquestionsprovidethe basisforbetterpreventionandtreatmentofdiseases. Many people contributed to the writing of this book: medical students in Denmark,studentsofepidemiologyattheIEAEEPEsummercourseinFlorence, Italy,andstudentsofpublichealthinLosAngeles. Withouttechnicalassistance v vi Preface fromGitteNielsen,JenadeShelley,NinaHoheandPamMasangkaythebookwould neverhavematerialized. LosAngeles,California JornOlsen Odense,Denmark KaareChristensen IowaCity,Iowa JeffMurray Stockholm,Sweden AndersEkbom Contents Part I Descriptive Epidemiology 1 Measures of Disease Occurrence ...3 IncidenceandPrevalence ...4 Incidence...6 RatesandDynamicPopulations ...7 CalculatingObservationTime...9 Prevalence,Incidence,Duration ...10 MortalityandLifeExpectancy ...11 LifeExpectancy ...12 References...13 2 Estimates of Associations ...15 3 Age Standardization...19 4 Causes of Diseases ...23 References...28 5 Descriptive Epidemiology in Public Health...29 GraphicalModelsofCausalLinks ...33 References...35 6 Descriptive Epidemiology in Genetic Epidemiology...37 OccurrenceDatainGeneticEpidemiology ...37 ClusteringofTraitsandDiseasesinFamilies ...38 TheOccurrenceofGeneticDiseases ...40 References...41 7 Descriptive Epidemiology in Clinical Epidemiology...43 SuddenInfantDeathSyndrome(SIDS)...44 CytologicalScreeningforCervixCancer ...45 ChangesinTreatmentofJuvenileDiabetes ...46 References...47 vii viii Contents Part II Analytical Epidemiology 8 Design Options...51 CommonDesignsUsedtoEstimateAssociations...51 EcologicalStudy ...52 Case-ControlStudy...54 CohortStudy ...5 5 ExperimentalStudy ...56 Reference ...57 9 Follow-Up Studies ...59 TheNon-experimentalFollow-Up(Cohort)Study ...59 StudyingRiskasaFunctionofBMI ...60 LongitudinalExposureData...62 DifferentTypesofCohortorFollow-UpStudies...63 10 Case-Control Studies...67 Case-CohortSampling ...69 DensitySamplingofControls...69 Case-Non-caseStudy...71 PatientControls ...72 SecondaryIdenti cationoftheSourcePopulation ...74 Case-ControlStudiesUsingPrevalentCases...74 WhentoDoaCase-ControlStudy? ...77 References...78 11 The Cross-Sectional Study...79 12 The Randomized Controlled Trial (RCT) ...81 Reference ...

Therearemanygoodepidemiologytextbooksonthemarket,butmostoftheseare addressedtostudentsofpublichealthorpeoplewhodoclinicalresearchwithe- demiologicmethods. Thereisaneedforashortintroductiononhowepidemiologic methodsareusedinpublichealth,geneticandclinicalepidemiology,becausehealth professionalsneedtoknowbasicepidemiologicmethodscoveringetiologicaswell asprognosticfactorsofdiseases. Theyneedtoknowmoreaboutmethodologythan introductorytextsonpublichealthhavetooffer. Insomehealthfaculties,epidemiologyisnotevenpartoftheteachingcurri- lum. Webelievethistobeaseriousmistake. Medicalstudentsarestudentsofall aspectsofdiseasesandhealth. Withoutknowingsomethingaboutepidemiologythe cliniciansandotherhealthprofessionalscannotreadagrowingpartofthesci- ti cliteratureinanyreasonablycriticalwayandcannotnavigateintheworldof "evidence-basedmedicineandevidence-basedprevention. "Withoutskillsine- demiologicmethodologytheyareinthehandsofexpertsthatmaynotonlyhavean interestinhealth. Some health professionals may believe that only common sense is needed to conductepidemiologicalstudies,butthescienti cliteratureandthepublicdebate onhealthissuesindicatethatcommonsenseisofteninshortsupplyandmaynot thrivewithoutsomeformaltraining. Epidemiologic methods play a key role in identifying environmental, social, and genetic determinants of diseases. Clinical epidemiology addresses the tr- sitionfromdiseasetohealthortowardmortalityorsocialormedicalhandicaps. Publichealthepidemiologyaddressesthetransitionfrombeinghealthytobeingnot healthy. Descriptiveepidemiologyprovidesthediseasepatternthatisneededtolook athealthinabroadperspectiveandtosettheprioritiesright. Epidemiologyisabasic scienceofmedicinewhichaddresseskeyquestionssuchas"Whobecomesill?"and "Whatareimportantprognosticfactors?"Answerstosuchquestionsprovidethe basisforbetterpreventionandtreatmentofdiseases. Many people contributed to the writing of this book: medical students in Denmark,studentsofepidemiologyattheIEAEEPEsummercourseinFlorence, Italy,andstudentsofpublichealthinLosAngeles. Withouttechnicalassistance v vi Preface fromGitteNielsen,JenadeShelley,NinaHoheandPamMasangkaythebookwould neverhavematerialized. LosAngeles,California JornOlsen Odense,Denmark KaareChristensen IowaCity,Iowa JeffMurray Stockholm,Sweden AndersEkbom Contents Part I Descriptive Epidemiology 1 Measures of Disease Occurrence ...3 IncidenceandPrevalence ...4 Incidence...6 RatesandDynamicPopulations ...7 CalculatingObservationTime...9 Prevalence,Incidence,Duration ...10 MortalityandLifeExpectancy ...11 LifeExpectancy ...12 References...13 2 Estimates of Associations ...15 3 Age Standardization...19 4 Causes of Diseases ...23 References...28 5 Descriptive Epidemiology in Public Health...29 GraphicalModelsofCausalLinks ...33 References...35 6 Descriptive Epidemiology in Genetic Epidemiology...37 OccurrenceDatainGeneticEpidemiology ...37 ClusteringofTraitsandDiseasesinFamilies ...38 TheOccurrenceofGeneticDiseases ...40 References...41 7 Descriptive Epidemiology in Clinical Epidemiology...43 SuddenInfantDeathSyndrome(SIDS)...44 CytologicalScreeningforCervixCancer ...45 ChangesinTreatmentofJuvenileDiabetes ...46 References...47 vii viii Contents Part II Analytical Epidemiology 8 Design Options...51 CommonDesignsUsedtoEstimateAssociations...51 EcologicalStudy ...52 Case-ControlStudy...54 CohortStudy ...5 5 ExperimentalStudy ...56 Reference ...57 9 Follow-Up Studies ...59 TheNon-experimentalFollow-Up(Cohort)Study ...59 StudyingRiskasaFunctionofBMI ...60 LongitudinalExposureData...62 DifferentTypesofCohortorFollow-UpStudies...63 10 Case-Control Studies...67 Case-CohortSampling ...69 DensitySamplingofControls...69 Case-Non-caseStudy...71 PatientControls ...72 SecondaryIdenti cationoftheSourcePopulation ...74 Case-ControlStudiesUsingPrevalentCases...74 WhentoDoaCase-ControlStudy? ...77 References...78 11 The Cross-Sectional Study...79 12 The Randomized Controlled Trial (RCT) ...81 Reference ...

This book is an introductory text for those people who need to know more about the scientific principles behind the study of the causes of disease occurence. As most people spend a large part of their lives at work, and as some people may be at risk of being exposed to harmful substances at high levels, workers protection should have a high priority. Studies in the workplace can help to identify causes of occupational diseases, and the outcome of such investigations should be applied when the effects of protective action are evaluated. In searching for occupational causes of diseases, epidemiological principles should be used, even at the factory level. Applying strict logical principles to the collection of data concerning worker's experience with ill-health ensures that a useful insight is gained into the causes of disease, and that data are obtained in a format suitable for subsequent larger-scale studies.

This book marks the 50th anniversary of the foundation of the International Epidemiological Association (IEA). It is a unique compendium by the world's leading epidemiologists of how the field has developed, and how it can be (and has been) applied to the control of common conditions and threats to public health. Five distinct sections guide the reader through the wealth of material: * Gives an historical account of the concepts and ideas, and current importance of epidemiology to global health issues and to organisations such as the WHO. * Illustrates the advances and contributions to epidemiologic knowledge and the control of disease in specific areas such as cancer, cardiovascular disease, respiratory disease, tuberculosis, maternal and child health, non-biologic disorders such as war and disasters, and new infectious diseases. * Outlines the use of epidemiology in areas such as public health, health services, occupational and environmental medicine, social epidemiology and nutrition. * Discusses methodological developments such as statistics, information sources, investigation of disease outbreaks and clinical epidemiology. * Looks at how the subject has developed internationally, with perspectives on regions such as the Americas, Poland, Spain, Eastern Mediterranean, New Zealand, China, Thailand and Japan. This remarkable insight into how epidemiology has developed is essential reading for both existing and aspiring epidemiologists.

Teaching epidemiology requires skill and knowledge, combined with a clear teaching strategy and good pedagogic skills. The general advice is simple: if you are not an expert on a topic, try to enrich your background knowledge before you start teaching. The new edition of Teaching Epidemiology helps you to do this and, by providing world-expert teachers' advice on how best to structure teaching, providing a unique insight into what has worked in their hands. This book will help you to tailor your own epidemiology teaching programme. The fourth edition of this established text has been fully revised and updated, drawing on new research findings and recently developed methods including research technologies in genetic epidemiology and method development in relation to causal analysis. Analytical tools provide teachers in the field with the skills to guide students at both undergraduate and postgraduate levels. Each chapter in Teaching Epidemiology comprises key concepts in epidemiology, subject specific methodologies, and disease specific issues, to provide expert assistance in the teaching of a wide range of epidemiology courses.