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Contribution to Book
Chapter 1 Considerations Regarding the Epidemiology and Public Health Burden of Asthma
Asthma, Health and Society: A Public Health Perspective (2010)
  • Earl S. Ford
  • David M. Mannino
Abstract

Epidemiology has been defined as the study of the distribution and determinants of diseases and health. Commonly used epidemiological study designs are ecological studies, cross-sectional studies, case-control studies, prospective studies, and randomized trials. In an ecological study, levels of potential or actual risk factors are correlated with levels of disease across distinct geographically defined populations either among countries or within countries. In a cross-sectional study, a sample of participants is selected and subsequently those with a particular condition are compared with those who do not have that condition. Such studies provide solid information about the prevalence of a condition and the attendant risk factors. However, cross-sectional studies provide weaker evidence for potential associations between possible risk factors and outcomes than case-control or prospective studies. In a case-control study, people with a condition are selected and a separate control group is selected, and then the two groups are compared. These studies are usually performed to look for associations between potential risk factors and disease. Furthermore, case-control studies are a practical method to study associations for diseases that are relatively rare. In a prospective study (cohort study, panel study, longitudinal study), a sample of participants is selected and they are followed forward in time. These studies provide the most compelling evidence for possible causal relationships between potential risk factors and diseases, in part because the exposure of interest occurs prior to the outcome. Cross-sectional studies, case-control studies, and prospective studies are commonly referred to as observational studies. Each of these study designs is subject to various biases. Thus, the results from studies using these various study designs must be interpreted in the context of potential bias. In a randomized clinical trial, participants with a condition are selected, and they are then randomly assigned to one or more intervention groups or a control group. In a randomized community trial, communities are selected and randomly allocated to receiving an intervention or no or lower-level intervention. Such trials are generally considered to provide the most rigorous evidence supporting the causal relationship between a risk factor and disease or the usefulness of a specific treatment.

Keywords
  • Adolescents,
  • Asthma,
  • Asthma Policy,
  • Chronic Disease,
  • Environmental Factors,
  • Genetic Factors,
  • Management of Asthma,
  • Public Health,
  • Screening for Asthma,
  • epidemiology,
  • social ecology
Publication Date
2010
Editor
Andrew Harver, Harry Kotses
Publisher
Springer Science+Business Media, LLC
Citation Information
Earl S. Ford and David M. Mannino. "Chapter 1 Considerations Regarding the Epidemiology and Public Health Burden of Asthma" Asthma, Health and Society: A Public Health Perspective (2010)
Available at: http://works.bepress.com/david_mannino/220/