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A Brief Introduction to Epidemiology - VIII (Epidemiologic Research Designs: Cross-Sectional/Prevalence Studies). Betty C. Jung, RN, MPH, CHES . Learning/Performance Objectives. To develop an understanding of: What cross-sectional studies are The value of such studies The basic methodology
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A Brief Introduction to Epidemiology - VIII(Epidemiologic Research Designs: Cross-Sectional/Prevalence Studies) Betty C. Jung, RN, MPH, CHES
Learning/Performance Objectives To develop an understanding of: What cross-sectional studies are The value of such studies The basic methodology Pros and cons of such studies
Introduction Epidemiology studies the distribution of disease in a number of ways. The two major categories of epidemiological studies are: Observational and experimental studies. Most epidemiological studies are observational.
Epidemiological Study Designs • Observational Studies - examine associations between risk factors and outcomes (Analytical - determinants and risk of disease, and descriptive - patterns and frequency of disease) • Intervention Studies - explore the association between interventions and outcomes. (Experimental studies or clinical trials)
Research Designs in Analytic Epidemiology • Ecologic Designs Cross-Sectional Study • Case-Control Study • Cohort Study
Cross-Sectional Studies • “Snapshot Studies” (Paffenbarger, 1988) • Observations at a single hypothetical point in time • Each subject assessed once at point in time. • Point Prevalence Studies
Examples • National Health & Nutrition Examination Surveys - allow for current estimates of prevalence for health parameters • Youth Risk Behavior Surveys - prevalence of prior health-risk behaviors
Value • Observe high prevalence of risk factors in those with disease • Suggests possibility of certain risk factors as cause of common disease • Quantify with point prevalence rates
Value • Cannot tell why any health differential exist, but that they do exist • Good for generating hypotheses about the cause of disease • Can be used to initiate and evaluate effective health services programs • Most commonly used strategy
Pros • One time exam/interview • Good for program and service planning • To determine associations between variables and generate hypotheses • Description of relative distribution, directs case finding
Cons • Cannot predict future health event happenings • Limited usefulness for outbreak and epidemics • Does not allow to determine which came first • Only describes what exist at time of study
References For Internet Resources on the topics covered in this lecture, check out my Web site: http://www.bettycjung.net