, FOU RTH ED ITION
ESSENTIALS OF
Epidemiology
IN PUBLIC HEALTH
Ann Aschengrau, ScD
Professor, Department of Epidemiology
Boston University School of Public Health
Boston, Massachusetts
George R. Seage III, DSc
Professor of Epidemiology
Harvard T.H. Chan School of Public Health
Boston, Massachusetts
,World Headquarters
Jones & Bartlett Learning
5 Wall Street
Burlington, MA 01803
978-443-5000
www.jblearning.com
Jones & Bartlett Learning books and products are available through most bookstores and online booksellers. To contact Jones & Bartlett
Learning directly, call 800-832-0034, fax 978-443-8000, or visit our website, www.jblearning.com.
Substantial discounts on bulk quantities of Jones & Bartlett Learning publications are available to corporations, professional
associations, and other qualified organizations. For details and specific discount information, contact the special sales department at
Jones & Bartlett Learning via the above contact information or send an email to .
Copyright © 2020 by Jones & Bartlett Learning, LLC, an Ascend Learning Company
All rights reserved. No part of the material protected by this copyright may be reproduced or utilized in any form, electronic or mechanical,
including photocopying, recording, or by any information storage and retrieval system, without written permission from the copyright owner.
The content, statements, views, and opinions herein are the sole expression of the respective authors and not that of Jones & Bartlett
Learning, LLC. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or
otherwise does not constitute or imply its endorsement or recommendation by Jones & Bartlett Learning, LLC and such reference shall not
be used for advertising or product endorsement purposes. All trademarks displayed are the trademarks of the parties noted herein. Essentials
of Epidemiology in Public Health, Fourth Edition is an independent publication and has not been authorized, sponsored, or otherwise
approved by the owners of the trademarks or service marks referenced in this product.
There may be images in this book that feature models; these models do not necessarily endorse, represent, or participate in the activities
represented in the images. Any screenshots in this product are for educational and instructive purposes only. Any individuals and scenarios
featured in the case studies throughout this product may be real or fictitious, but are used for instructional purposes only.
This publication is designed to provide accurate and authoritative information in regard to the Subject Matter covered. It is sold with the
understanding that the publisher is not engaged in rendering legal, accounting, or other professional service. If legal advice or other expert
assistance is required, the service of a competent professional person should be sought.
12843-7
Production Credits
VP, Product Management: David D. Cella Composition: codeMantra U.S. LLC
Director of Product Management: Michael Brown Cover Design: Kristin E. Parker
Product Specialist: Carter McAlister Rights & Media Specialist: John Rusk
Production Manager: Carolyn Rogers Pershouse Media Development Editor: Shannon Sheehan
Associate Production Editor, Navigate: Jamie Reynolds Cover Image (Title Page, Chapter Opener):
Senior Marketing Manager: Sophie Fleck Teague © Smartboy10/DigitalVision Vectors/Getty Images
Manufacturing and Inventory Control Supervisor: Amy Bacus Printing and Binding: Bang Printing
Cover Printing: Bang Printing
Library of Congress Cataloging-in-Publication Data
Names: Aschengrau, Ann, author. | Seage, George R., author.
Title: Essentials of epidemiology in public health / Ann Aschengrau, ScD,
Professor of Epidemiology, Boston University School of Public Health,
George R. Seage III, ScD, Professor of Epidemiology, Harvard T.H. Chan
School of Public Health.
Description: Fourth edition. | Burlington, MA : Jones & Bartlett Learning,
[2020] | Includes bibliographical references and index.
Identifiers: LCCN 2018023772 | ISBN 9781284128352 (paperback)
Subjects: LCSH: Epidemiology. | Public health. | Social medicine. | BISAC:
EDUCATION / General.
Classification: LCC RA651 .A83 2020 | DDC 614.4–dc23
LC record available at https://lccn.loc.gov/2018023772
6048
Printed in the United States of America
22 21 20 19 18 10 9 8 7 6 5 4 3 2 1
, © Smartboy10/DigitalVision Vectors/Getty Images
Contents
Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Chapter 3 Comparing Disease
Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi Frequencies. . . . . . . . . . . . . . . . 57
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Chapter 1 The Approach and Evolution Data Organization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
of Epidemiology . . . . . . . . . . . . . . 1 Measures of Comparison . . . . . . . . . . . . . . . . . . . . . . . . 61
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Direct Standardization. . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Definition and Goals of Public Health. . . . . . . . . . . . . 2 Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Sources of Scientific Knowledge in Public Health. . 3 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Definition and Objectives of Epidemiology. . . . . . . . 5 Chapter Questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Historical Development of Epidemiology. . . . . . . . . 8
Modern Epidemiology. . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Chapter 4 Sources of Public
Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Health Data. . . . . . . . . . . . . . . . 77
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Chapter Questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Census of the U.S. Population. . . . . . . . . . . . . . . . . . . . 78
Chapter 2 Measures of Disease Vital Statistics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Frequency. . . . . . . . . . . . . . . . . . 33 National Survey of Family Growth. . . . . . . . . . . . . . . . 84
National Health Interview Survey. . . . . . . . . . . . . . . . 84
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
National Health and Nutrition
Definition of a Population. . . . . . . . . . . . . . . . . . . . . . . . 34 Examination Survey. . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Definitions of Health and Disease. . . . . . . . . . . . . . . . 36 Behavioral Risk Factor Surveillance System. . . . . . . 85
Changes in Disease Definitions . . . . . . . . . . . . . . . . . . 37 National Health Care Surveys. . . . . . . . . . . . . . . . . . . . 86
Measuring Disease Occurrence. . . . . . . . . . . . . . . . . . 39 National Notifiable Diseases
Types of Calculations: Ratios, Surveillance System. . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Proportions, and Rates. . . . . . . . . . . . . . . . . . . . . . . . 40 Surveillance of HIV Infection. . . . . . . . . . . . . . . . . . . . . 87
Measures of Disease Frequency. . . . . . . . . . . . . . . . . . 41 Reproductive Health Statistics . . . . . . . . . . . . . . . . . . . 88
Commonly Used Measures of Disease National Immunization Survey. . . . . . . . . . . . . . . . . . . 89
Frequency in Public Health. . . . . . . . . . . . . . . . . . . . 51
Survey of Occupational Injuries
Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 and Illnesses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 National Survey on Drug Use
Chapter Questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 and Health. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
iii
ESSENTIALS OF
Epidemiology
IN PUBLIC HEALTH
Ann Aschengrau, ScD
Professor, Department of Epidemiology
Boston University School of Public Health
Boston, Massachusetts
George R. Seage III, DSc
Professor of Epidemiology
Harvard T.H. Chan School of Public Health
Boston, Massachusetts
,World Headquarters
Jones & Bartlett Learning
5 Wall Street
Burlington, MA 01803
978-443-5000
www.jblearning.com
Jones & Bartlett Learning books and products are available through most bookstores and online booksellers. To contact Jones & Bartlett
Learning directly, call 800-832-0034, fax 978-443-8000, or visit our website, www.jblearning.com.
Substantial discounts on bulk quantities of Jones & Bartlett Learning publications are available to corporations, professional
associations, and other qualified organizations. For details and specific discount information, contact the special sales department at
Jones & Bartlett Learning via the above contact information or send an email to .
Copyright © 2020 by Jones & Bartlett Learning, LLC, an Ascend Learning Company
All rights reserved. No part of the material protected by this copyright may be reproduced or utilized in any form, electronic or mechanical,
including photocopying, recording, or by any information storage and retrieval system, without written permission from the copyright owner.
The content, statements, views, and opinions herein are the sole expression of the respective authors and not that of Jones & Bartlett
Learning, LLC. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or
otherwise does not constitute or imply its endorsement or recommendation by Jones & Bartlett Learning, LLC and such reference shall not
be used for advertising or product endorsement purposes. All trademarks displayed are the trademarks of the parties noted herein. Essentials
of Epidemiology in Public Health, Fourth Edition is an independent publication and has not been authorized, sponsored, or otherwise
approved by the owners of the trademarks or service marks referenced in this product.
There may be images in this book that feature models; these models do not necessarily endorse, represent, or participate in the activities
represented in the images. Any screenshots in this product are for educational and instructive purposes only. Any individuals and scenarios
featured in the case studies throughout this product may be real or fictitious, but are used for instructional purposes only.
This publication is designed to provide accurate and authoritative information in regard to the Subject Matter covered. It is sold with the
understanding that the publisher is not engaged in rendering legal, accounting, or other professional service. If legal advice or other expert
assistance is required, the service of a competent professional person should be sought.
12843-7
Production Credits
VP, Product Management: David D. Cella Composition: codeMantra U.S. LLC
Director of Product Management: Michael Brown Cover Design: Kristin E. Parker
Product Specialist: Carter McAlister Rights & Media Specialist: John Rusk
Production Manager: Carolyn Rogers Pershouse Media Development Editor: Shannon Sheehan
Associate Production Editor, Navigate: Jamie Reynolds Cover Image (Title Page, Chapter Opener):
Senior Marketing Manager: Sophie Fleck Teague © Smartboy10/DigitalVision Vectors/Getty Images
Manufacturing and Inventory Control Supervisor: Amy Bacus Printing and Binding: Bang Printing
Cover Printing: Bang Printing
Library of Congress Cataloging-in-Publication Data
Names: Aschengrau, Ann, author. | Seage, George R., author.
Title: Essentials of epidemiology in public health / Ann Aschengrau, ScD,
Professor of Epidemiology, Boston University School of Public Health,
George R. Seage III, ScD, Professor of Epidemiology, Harvard T.H. Chan
School of Public Health.
Description: Fourth edition. | Burlington, MA : Jones & Bartlett Learning,
[2020] | Includes bibliographical references and index.
Identifiers: LCCN 2018023772 | ISBN 9781284128352 (paperback)
Subjects: LCSH: Epidemiology. | Public health. | Social medicine. | BISAC:
EDUCATION / General.
Classification: LCC RA651 .A83 2020 | DDC 614.4–dc23
LC record available at https://lccn.loc.gov/2018023772
6048
Printed in the United States of America
22 21 20 19 18 10 9 8 7 6 5 4 3 2 1
, © Smartboy10/DigitalVision Vectors/Getty Images
Contents
Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Chapter 3 Comparing Disease
Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi Frequencies. . . . . . . . . . . . . . . . 57
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Chapter 1 The Approach and Evolution Data Organization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
of Epidemiology . . . . . . . . . . . . . . 1 Measures of Comparison . . . . . . . . . . . . . . . . . . . . . . . . 61
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Direct Standardization. . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Definition and Goals of Public Health. . . . . . . . . . . . . 2 Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Sources of Scientific Knowledge in Public Health. . 3 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Definition and Objectives of Epidemiology. . . . . . . . 5 Chapter Questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Historical Development of Epidemiology. . . . . . . . . 8
Modern Epidemiology. . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Chapter 4 Sources of Public
Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Health Data. . . . . . . . . . . . . . . . 77
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Chapter Questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Census of the U.S. Population. . . . . . . . . . . . . . . . . . . . 78
Chapter 2 Measures of Disease Vital Statistics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Frequency. . . . . . . . . . . . . . . . . . 33 National Survey of Family Growth. . . . . . . . . . . . . . . . 84
National Health Interview Survey. . . . . . . . . . . . . . . . 84
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
National Health and Nutrition
Definition of a Population. . . . . . . . . . . . . . . . . . . . . . . . 34 Examination Survey. . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Definitions of Health and Disease. . . . . . . . . . . . . . . . 36 Behavioral Risk Factor Surveillance System. . . . . . . 85
Changes in Disease Definitions . . . . . . . . . . . . . . . . . . 37 National Health Care Surveys. . . . . . . . . . . . . . . . . . . . 86
Measuring Disease Occurrence. . . . . . . . . . . . . . . . . . 39 National Notifiable Diseases
Types of Calculations: Ratios, Surveillance System. . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Proportions, and Rates. . . . . . . . . . . . . . . . . . . . . . . . 40 Surveillance of HIV Infection. . . . . . . . . . . . . . . . . . . . . 87
Measures of Disease Frequency. . . . . . . . . . . . . . . . . . 41 Reproductive Health Statistics . . . . . . . . . . . . . . . . . . . 88
Commonly Used Measures of Disease National Immunization Survey. . . . . . . . . . . . . . . . . . . 89
Frequency in Public Health. . . . . . . . . . . . . . . . . . . . 51
Survey of Occupational Injuries
Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 and Illnesses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 National Survey on Drug Use
Chapter Questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 and Health. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
iii