Explain the Various Types of Observational Studies

question 107

Multiple Choice

Explain the Various Types of Observational Studies
-A researcher wanted to determine whether colon cancer was associated with eating meat. He selected a sample of 500 men with colon cancer and an equal number of men without colon cancer. The two groups were matched - in other words they were similar in terms of age, occupation, income, and exercise levels. Histories on the amount of meat consumed over the previous twenty years were obtained for all men. The total amount of meat that each man eaten in the previous twenty years was estimated. The meat consumption was compared for the two groups.

• A) retrospective; Individuals are asked to look back in time
• B) cross-sectional; Information is collected at a specific point in time.
• C) cohort; Individuals are observed over a long period of time.

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Definitions:

Antigens

Foreign substances that induce an immune response in the body, especially the production of antibodies.

Antibodies

Proteins produced by the immune system to identify and neutralize foreign objects like bacteria and viruses.

White Blood Cells

Cells of the immune system involved in defending the body against both infectious disease and foreign materials.

Heart Attack

A medical emergency characterized by the death of heart muscle due to the loss of blood supply, commonly caused by a blockage in one or more of the coronary arteries.