Wilfried Karmaus Department of Epidemiology, MSU EPI 824 Reproductive Epidemiology Fall 2002

Objectives (1) Level 6: Evaluation (critique, appraise, judge)Level 6: Evaluation (critique, appraise, judge) Level 5: Synthesize (integrate, collaborate)Level 5: Synthesize (integrate, collaborate) Level 4: Analyze (hypothesis, structure)Level 4: Analyze (hypothesis, structure) Level 3: Application (utilize, produce)Level 3: Application (utilize, produce) Level 2: Comprehension (translate, discuss)Level 2: Comprehension (translate, discuss) Level 1: Knowledge (define, enumerate, recall)Level 1: Knowledge (define, enumerate, recall)

Problem Solving Cycle in Public Health Definition of the problem   Goals and priority setting Studying the effects   Application and steering of the measures Strategies for problem solving   Operational plan

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

PredictorsOutcomes General etiologic model: X1X1 X2X2 X3X3 Y1Y1 problem: collinearity Y2Y2 Y3Y3 (atopic eczema) (increased cholesterol) (bronchial hyperreactivity) Latent factor for these three outcomes? PredictorsOutcomes X1X1 X2X2 X3X3 Y1Y1 problem: collinearity Y2Y2 Y3Y3 (infertility) (fetal loss) (birth defect) conditional interdependence (selective survival) Etiologic model for reproductive epidemiology: = =

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

Initiation of the etiologic process (onset of the first cause) Initiation of the patholo- gic process (disease starts) Clinical detection of the disease (onset of sign and symptoms) Outcome of the disease (subsequent change in health status or death) Latency Duration Primary PreventionSecondary PreventionTertiary Prevention

Low birth weight and exposure to wood preservatives (PCP, PCDD/F) Source: Karmaus et. al. 1995

% without conception exposed at starting time (n=86) not exposed at starting time (n=1001) months Living on a contaminated waste site and time to pregnancy

Study design in reproductive epidemiology golden standard = prospective study time starting time of unprotected intercourse detected/ recognized conception birth, miscarriage, stillbirth starting time end of unprotec- ted intercourse time to pregancy period of unprotected intercourse gestational age

Changes in sex ratio

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.