Three Observational Study Designs (BHS 210 Module 5) (Essay Sample)

BHS 210 Module 5 Discussion-Distinguishing Three Observational Study Designs
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Observational studies
In observational studies, researchers observe outcomes, but there is no intervention unlike experimental studies, and the researcher has no control over the exposure factor (Friis, 2010). Crosse sectional surveys, cohort studies and case-control studies are the three main observational studies.
Cross sectional studies
The studies focus on prevalence by focusing on exposure and outcomes, where there is comparison between the groups. Nonetheless, since it is difficult to sequence outcome and exposure, theses studies are the basis for further rigorous studies including case-control, cohort study and RCT (Carlson & Morrison 2009).
Cohort study
These studies focus on the level of exposure and determining incidence rates for different exposure groups and hence researchers follow the subjects over time (Carlson & Morrison 2009). A researcher typically studies various outcomes of the study, and even when the association is weak, the observed findings link exposure with outcomes.
Case-control design
In case-control studies, researchers focus on outcomes (cases) and compare results with subjects with no outcome as the ‘controls’. These studies are appropriate when outcome is rare and evidence on past exposure is reliable (Carlson & Morrison, 2009).
Observational study of a population grouped into smokers and non-smokers
By identifying the subjects into smokers and non smokers, then it is possible to assess and compare infection rates or risks of a disease. The subjects are placed in the groups based on exposure, which is smoking. On the other hand, if the participants were divided into groups based on diseases the study design would have been case-control. The cohort study focuses on exposure status, identifying whether exposure to s...