Epidemiology Kept Simple introduces the epidemiological
principles and methods that are increasingly important in the
practice of medicine and public health. With minimum use of
technical language it fully explains terminology, concepts, and
techniques associated with traditional and modern epidemiology.
Topics include disease causality, epidemiologic measures,
descriptive epidemiology, study design, clinical and primary
prevention trials, observational cohort studies, case-control
studies, and the consideration of random and systematic error in
studies of causal factors. Chapters on the infectious disease
process, outbreak investigation, and screening for disease are also
included. The latter chapters introduce more advanced
biostatistical and epidemiologic techniques, such as survival
analysis, Mantel-Haenszel techniques, and tests for
interaction.

This third edition addresses all the requirements of the
American Schools of Public Health (ASPH) Epidemiological
Competencies, and provides enhanced clarity and

readability on this difficult subject. Updated with new practical
exercises, case studies and real world examples, this title helps
you develop the necessary tools to interpret epidemiological data
and prepare for board exams, and now also includes review questions
at the end of each chapter.

Epidemiology Kept Simple continues to provide an
introductory guide to the use of epidemiological methods for
graduate and undergraduate students studying public health, health
education and nursing, and for all practicing health professionals
seeking professional development.

B. Burt Gerstman, Professor in Department of Health Science, San Jose University, CA USA.

Epidemiology Kept Simple introduces the epidemiological principles and methods that are increasingly important in the practice of medicine and public health. With minimum use of technical language it fully explains terminology, concepts, and techniques associated with traditional and modern epidemiology. Topics include disease causality, epidemiologic measures, descriptive epidemiology, study design, clinical and primary prevention trials, observational cohort studies, case-control studies, and the consideration of random and systematic error in studies of causal factors. Chapters on the infectious disease process, outbreak investigation, and screening for disease are also included. The latter chapters introduce more advanced biostatistical and epidemiologic techniques, such as survival analysis, Mantel-Haenszel techniques, and tests for interaction.

This third edition addresses all the requirements of the American Schools of Public Health (ASPH) Epidemiological Competencies, and provides enhanced clarity and
readability on this difficult subject. Updated with new practical exercises, case studies and real world examples, this title helps you develop the necessary tools to interpret epidemiological data and prepare for board exams, and now also includes review questions at the end of each chapter.

Epidemiology Kept Simple continues to provide an introductory guide to the use of epidemiological methods for graduate and undergraduate students studying public health, health education and nursing, and for all practicing health professionals seeking professional development.

Preface to the Third Edition xi

Preface to the First Edition xiii

Acknowledgments xv

1 Epidemiology Past and Present 1

1.1 Epidemiology and its uses 2

1.2 Evolving patterns of morbidity and mortality 5

1.3 Selected historical figures and events 8

1.4 Chapter summary 30

Review questions 31

References 32

2 Causal Concepts 36

2.1 Natural history of disease 36

2.2 Variability in the expression of disease 40

2.3 Causal models 41

2.4 Causal inference 48

Exercises 58

Review questions 61

References 63

3 Epidemiologic Measures 66

3.1 Measures of disease frequency 67

3.2 Measures of association 74

3.3 Measures of potential impact 79

3.4 Rate adjustment 82

Exercises 90

Review questions 98

References 99

Addendum: additional mathematical details 101

4 Descriptive Epidemiology 104

4.1 Introduction 104

4.2 Epidemiologic variables 108

4.3 Ecological correlations 116

Exercises 121

Review questions 123

References 124

5 Introduction to Epidemiologic Study Design 126

5.1 Etiologic research 126

5.2 Ethical conduct of studies involving human subjects 129

5.3 Selected study design elements 130

5.4 Common types of epidemiologic studies 137

Exercises 138

Review questions 140

References 141

6 Experimental Studies 142

6.1 Introduction 142

6.2 Historical perspective 144

6.3 General concepts 146

6.4 Data analysis 152

Exercises 156

Review questions 157

References 157

7 Observational Cohort Studies 159

7.1 Introduction 159

7.2 Historical perspective 161

7.3 Assembling and following a cohort 163

7.4 Prospective, retrospective, and ambidirectional cohorts 164

7.5 Addressing the potential for confounding 165

7.6 Data analysis 166

7.7 Historically important study: Wade Hampton Frost's birth cohorts 170

Exercises 174

Review questions 177

References 177

8 Case-Control Studies 180

8.1 Introduction 180

8.2 Identifying cases and controls 182

8.3 Obtaining information on exposure 185

8.4 Data analysis 186

8.5 Statistical justifications of case-control odds ratio as relative risks 193

Exercises 194

Review questions 198

References 199

9 Error in Epidemiologic Research 201

9.1 Introduction 201

9.2 Random error (imprecision) 203

9.3 Systematic error (bias) 209

Exercises 217

Review questions 219

References 220

10 Screening for Disease 222

10.1 Introduction 223

10.2 Reliability (agreement) 224

10.3 Validity 228

Summary 238

Exercises 239

Review questions 243

References 243

10.4 Chapter addendum (case study) 244

Further reading-screening for HIV 248

Further reading-general concepts of screening 248

Answers to case study: screening for antibodies to the human immunodeficiency virus 249

11 The Infectious Disease Process 255

11.1 The infectious disease process 255

11.2 Herd immunity 265

Exercises 267

Review questions 268

References 270

12 Outbreak Investigation 271

12.1 Background 272

12.2 CDC prescribed investigatory steps 273

Review questions 282

References 283

References-a drug-disease outbreak 286

13 Confidence Intervals and p-Values 302

13.1 Introduction 303

13.2 Confidence intervals 304

13.3 p-Values 312

13.4 Minimum Bayes factors 319

References 322

14 Mantel-Haenszel Methods 323

14.1 Ways to prevent confounding 323

14.2 Simpson's paradox 325

14.3 Mantel-Haenszel methods for risk ratios 325

14.4 Mantel-Haenszel methods for other measures of association 329

Exercise 335

References 335

15 Statistical Interaction: Effect Measure Modification 337

15.1 Two types of interaction 337

15.2 Chi-square test for statistical 340

15.3 Strategy for stratified analysis 342

Exercises 344