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.

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 References 345 16 Case Definitions and Disease Classification 347 16.1 Case definitions 347 16.2 International classification of disease 351 16.3 Artifactual fluctuations in reported rates 353 16.4 Summary 354 References 355 17 Survival Analysis 356 17.1 Introduction 356 17.2 Stratifying rates by follow-up time 359 17.3 Actuarial method of survival analysis 360 17.4 Kaplan–Meier method of survival analysis 362 17.5 Comparing the survival experience of two groups 364 Exercises 369 References 371 18 Current Life Tables 373 18.1 Introduction 373 18.2 Complete life table 374 18.3 Abridged life table 380 Exercises 383 References 384 19 Random Distribution of Cases in Time and Space 385 19.1 Introduction 385 19.2 The Poisson distribution 386 19.3 Goodness of fit of the Poisson distribution 390 19.4 Summary 394 Exercises 395 References 396 Answers to Exercises and Review Questions 398 Appendix 1: 95% Confidence Limits for Poisson Counts 434 Appendix 2: Tail Areas in the Standard Normal (Z) Distribution: Double These Areas for Two-Sided p-Values 436 Appendix 3: Right-Tail Areas in Chi-Square Distributions 439 Appendix 4: Case Study—Cigarette Smoking and Lung Cancer 441 Appendix 5: Case Study—Tampons and Toxic Shock Syndrome 448 Index 455

Epidemiology Kept Simple AN INTRODUCTION TO TRADITIONAL AND MODERN EPIDEMIOLOGY THIRD EDITION B. Burt Gerstman 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 practical exercises, case studies and real world examples to help develop the necessary tools to interpret epidemiological data and prepare for board exams. 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.