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EPI 824 Reproductive Epidemiology Fall 2002. Wilfried Karmaus Department of Epidemiology, MSU karmaus@msu.edu. Objectives (1). Level 6: Evaluation (critique, appraise, judge) Level 5: Synthesize (integrate, collaborate) Level 4: Analyze (hypothesis, structure)
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EPI 824 Reproductive Epidemiology Fall 2002 Wilfried Karmaus Department of Epidemiology, MSU karmaus@msu.edu
Objectives (1) • Level 6: Evaluation (critique, appraise, judge) • Level 5: Synthesize (integrate, collaborate) • Level 4: Analyze (hypothesis, structure) • Level 3: Application (utilize, produce) • Level 2: Comprehension (translate, discuss) • Level 1: Knowledge (define, enumerate, recall)
Definition of the problem Goals and priority setting Studying the effects Application and steering of the measures Strategies for problem solving Operational plan Problem Solving Cycle in Public Health
Epidemiology: (Stallones 1980, Ann Rev Public Health 1:69-82) Axiom: Disease does not distribute randomly in human populations. Corollary 1: Aggregations of human diseases are manifested along axes of: • time • space • individual / group characteristics. Corollary 2: Variations in the frequency of human disease occur in response to: • variation in exposure • variation in susceptibility.
Outcomes of human reproduction Reproductive health Sex ratio
General etiologic model: Outcomes Y1 (atopic eczema) X2 X1 Y2 (increased cholesterol) Predictors X3 Y3 (bronchial hyperreactivity) problem: collinearity Latent factor for these three outcomes? Etiologic model for reproductive epidemiology: Predictors Outcomes Y1 (infertility) X2 X1 = Y2 (fetal loss) = X3 Y3 (birth defect) problem: collinearity conditional interdependence (selective survival)
Frequency of reproductive outcomes in humans Infertility/Subfecundity » 14-20% of all couples at risk Spontaneous abortions recognized: » 15% of all conceptions not recognized: » 20% malformations » 2-5% of all live births childhood cancer » 0.18% of all children
Latency Duration Clinical detection of the disease (onset of sign and symptoms) Initiation of the etiologic process (onset of the first cause) Initiation of the patholo-gic process (disease starts) Outcome of the disease (subsequent change in health status or death) Primary Prevention Secondary Prevention Tertiary Prevention
Low birth weight and exposure to wood preservatives (PCP, PCDD/F) Source: Karmaus et. al. 1995
% without conception Living on a contaminated waste site and time to pregnancy 1.0 0.8 0.6 0.4 0.2 0.0 0 6 12 18 24 30 36 42 48 54 60 months exposed at starting time (n=86) not exposed at starting time (n=1001)
Study design in reproductive epidemiology golden standard = prospective study starting time of unprotected intercourse detected/ recognized conception birth, miscarriage, stillbirth time time to pregancy gestational age starting time end of unprotec-ted intercourse period of unprotected intercourse
Reproductive epidemiology includes a wide variety of outcomes with: • different ways of measurements • different markers within physiologic and pathologic processes • different statistical approaches In the course you will learn • how to define reproductive outcomes • to review one outcomes and its etiology • to discuss empirical methods and • to apply some statistical methods.