Research Methods in Occupational Epidemiology

by Harvey Checkoway; Neil Pearce; Douglas J. Crawford-Brown

• ISBN13: 9780195052244
• ISBN10: 0195052242
• Format: Nonspecific Binding
• Copyright: 1989-05-25
• Publisher: Oxford University Press Academic US

Summary

Occupational epidemiology has emerged as a distinct subdiscipline of epidemiology and occupational medicine, addressing fundamental public health and scientific questions relating to the specification of exposure-response relationships, assessment of the adequacy of occupational exposure guidelines, and extrapolation of hazardous effects to other settings. This book reviews the wide range of principles and methods used in epidemiologic studies of working populations. It describes the historical development of occupational epidemiology, the approaches to characterizing workplace exposures, and the methods for designing and implementing epidemiologic studies. The relative strengths and limitations of different study designs are emphasized. Also included are more advanced discussions of statistical analysis, the estimation of doses to biological targets, and applications of the data derived from occupational epidemiology studies to disease modeling and risk assessment. The volume will serve both as a textbook in epidemiology and occupational medicine courses and as a practical handbook for the design, implementation, and interpretation of research in this field.

Author Biography

Harvey Checkoway, Ph.D., is Associate Professor in the Department of Environmental Health with a joint appointment in the Department of Epidemiology at the University of Washington School of Public Health and Community Medicine. Neil Pearce, Ph.D., is Lecturer in the Department of Community Health at the Wellington School of Medicine in New Zealand. Douglas J. Crawford-Brown is Associate Professor in the Department of Environmental Sciences and Engineering at the University of North Carolina.

Table of Contents

Introduction	3	(15)
Overview	3	(1)
Historical Background	4	(3)
Recognition of Occupational Diseases	4	(2)
Development of Systematic Epidemiologic Methods	6	(1)
Scope of Occupational Epidemiology	7	(11)
Identifying Occupational Hazards and Populations at Risk	9	(2)
Estimation of Effects	11	(2)
Causal Inference	13	(1)
References	14	(4)
Characterizing the Workplace Environment	18	(28)
Overview	18	(1)
General Concepts of Exposure and Dose	18	(3)
Definitions of Exposure and Dose Variables	19	(2)
Types and Sources of Exposure Data	21	(17)
Industry-Based Studies	21	(14)
Community-Based Studies	35	(3)
Classification of Exposure Levels	38	(4)
Exposure Classification for Specific Biological Targets	38	(2)
Combining Exposure Data from Various Sources	40	(2)
Summary	42	(4)
Glossary	43	(1)
References	43	(3)
Overview of Study Designs	46	(26)
Overview	46	(1)
Case Series	46	(1)
Cohort Studies	47	(7)
Prospective Cohort Studies	48	(3)
Historical Cohort Studies	51	(2)
Subcohort Analysis	53	(1)
Case-Control Studies	54	(4)
Industry-Based (Nested) Case-Control Studies	55	(1)
Registry-Based Case-Control Studies	56	(2)
Proportionate Mortality Studies	58	(3)
Cross-Sectional Studies	61	(1)
Connection Between Study Designs	62	(5)
Summary	67	(5)
Glossary	68	(1)
References	69	(3)
Issues of Study Design and Analysis	72	(31)
Overview	72	(1)
Precision and Validity	72	(5)
Precision	72	(5)
Validity	77	(1)
Selection Bias	77	(3)
Definition	77	(1)
The Healthy Worker Effect	78	(1)
Minimizing Selection Bias	79	(1)
Information Bias	80	(4)
Nondifferential Information Bias	80	(2)
Differential Information Bias	82	(1)
Assessment of Information Bias	83	(1)
Confounding	84	(12)
Definition	84	(1)
Relationship of Confounding to Selection and Information Bias	85	(1)
The Healthy Worker Effect Revisited	86	(5)
Other Confounders	91	(1)
Assessment of Confounding	92	(2)
Control of Confounding	94	(2)
Estimating Joint Effects	96	(7)
Joint Effects	96	(1)
Effect Modification	97	(1)
Glossary	98	(1)
Notation	99	(1)
References	99	(4)
Cohort Studies	103	(67)
Overview	103	(1)
Basic Cohort Design	103	(13)
Design Options: Prospective and Historical	103	(2)
Defining and Following the Study Cohort	105	(11)
Methods of Data Analysis	116	(14)
Risks and Rates	116	(5)
Stratum-Specific Rates	121	(1)
Summary Measures of Effect	122	(8)
Strategies of Analysis	130	(25)
Overall Cohort Analysis	130	(6)
Subcohort Analysis	136	(12)
Missing Exposure Data	148	(2)
Disease Induction and Latency Analysis	150	(5)
Planning a Cohort Study	155	(1)
Example of a Cohort Study: Asbestos Textile Plant Workers	156	(8)
Description of the Plant and Study Cohort	156	(1)
Vital Status Tracing and Cause of Death Determination	157	(1)
Results	158	(6)
Summary of Advantages and Limitations of Occupational Cohort Studies	164	(6)
Glossary	165	(1)
Notation	165	(1)
References	166	(4)
Case--Control Studies	170	(32)
Overview	170	(1)
Basic Study Design	171	(1)
Selection of Cases	172	(2)
Selection of Controls	174	(8)
Sampling Strategies	174	(3)
Matching	177	(2)
Sources of Controls	179	(1)
Issues in Control Selection	180	(2)
Exposure Data	182	(2)
Analysis	184	(8)
Crude Analysis	184	(2)
Stratified Analysis	186	(2)
Matched Analysis	188	(2)
Extension to Multiple Exposure Levels	190	(2)
Example: Nested Case-Control Study of Asbestos Textile Plant Workers	192	(5)
Study Design	192	(1)
Analysis: Dichotomous Exposure	193	(2)
Analysis: Multiple Exposure Levels	195	(1)
Discussion	196	(1)
Summary of Advantages and Limitations of Case-Control Studies	197	(5)
Glossary	198	(1)
Notation	198	(1)
References	199	(3)
Cross-Sectional Studies	202	(30)
Overview	202	(1)
Study Design Features	202	(5)
One-Time Surveys	203	(2)
Repeated Surveys	205	(2)
Sources of Health and Exposure Data	207	(1)
Health Outcome Data	207	(1)
Exposure Data	207	(1)
Subject Selection Options	208	(7)
Plant- or Industrywide Studies	208	(2)
Selection on Exposure Status	210	(1)
Selection on Disease Status	211	(1)
Comparison Populations	212	(3)
Methods of Data Analysis	215	(8)
Comparisons of Prevalence	215	(4)
Comparisons of Physiologic Variable Distributions	219	(4)
Sources of Bias in Cross-sectional Studies	223	(4)
Temporal Relationship of Exposure to Disease	223	(1)
Studying Disease Prevalence	224	(1)
Selection Bias	224	(2)
Information Bias	226	(1)
Planning a Cross-sectional Study	227	(1)
Data Requirements	227	(1)
Subject Selection	228	(1)
Summary of Advantages and Limitations of Occupational Cross-sectional Studies	228	(4)
Glossary	229	(1)
Notation	230	(1)
References	230	(2)
Advanced Statistical Analysis	232	(32)
Overview	232	(1)
Importance of Time-Related Analysis	232	(1)
General Linear Models	233	(4)
The Exponential Model	234	(1)
Maximum Likelihood Estimation	235	(1)
Other Models	236	(1)
Specific Applications	237	(6)
Poisson Regression	237	(3)
The Proportional Hazards Model	240	(1)
Logistic Regression	241	(2)
Defining the Model	243	(7)
Introduction	243	(1)
Exposure	243	(1)
Exposure-Response Estimation	244	(1)
Confounding	245	(1)
Joint Effects	246	(1)
Regression Diagnostics	247	(3)
Example: Study of Asbestos Textile Plant Workers	250	(9)
Introduction	250	(1)
Computational Methods	250	(3)
Importance of Time-Related Analysis	253	(1)
Model Definition	253	(4)
Comparison of Modeling Methods	257	(2)
Discussion	259	(1)
Summary of Advantages and Limitations of Modeling	259	(5)
Glossary	260	(1)
Notation	260	(1)
References	261	(3)
Dose and Exposure Modeling	264	(27)
Overview	264	(1)
Fundamental Definitions of Exposure and Dose Parameters	264	(4)
Exposure Variables	265	(1)
Dose Variables	266	(2)
Biomathematical Models of Organ Burden and Dose	268	(8)
Examples of Dose and Exposure Modeling	276	(9)
Inhaled Soluble Uranium Compounds	276	(4)
Inhaled Asbestos Fibers	280	(5)
Summary	285	(6)
Glossary	287	(1)
Notation	288	(1)
References	289	(2)
Special Applications of Occupational Epidemiology Data	291	(42)
Overview	291	(2)
The Armitage-Doll Multistage Model of Carcinogenesis	293	(9)
Introduction	293	(2)
Lifetime Exposure	295	(1)
Exposure Commencing Subsequent to Birth	295	(1)
Fixed Duration of Exposure	296	(2)
Continuing Exposure	298	(1)
Implications	298	(4)
Application to Study of Asbestos Textile Plant Workers	302	(7)
Induction Time Analyses	302	(2)
Relationship of Risk with Age at First Employment and Length of Follow-up	304	(3)
Direct Fitting of the Armitage-Doll Model	307	(2)
Some Additional Comments on the Armitage-Doll Model	309	(1)
Introduction to Risk Assessment	309	(1)
The Mathematics of Risk Assessment	310	(11)
Dose-Response Models	311	(4)
Lifetime Risk	315	(3)
Probability of Causation	318	(3)
Examples of Occupational Epidemiology in Risk Assessment	321	(6)
The Dose-Response Curve	321	(2)
Temporal Extrapolation	323	(1)
Lifetime Risk	324	(1)
Probability of Causation	325	(1)
The No Observed Effects Level	326	(1)
Discussion	327	(6)
Glossary	329	(1)
Notation	329	(1)
References	330	(3)
Index	333