A case-control study was conducted to evaluate the relationship between aspirin use and the risk of colon cancer. 2,000 cases and 2,000 controls were enrolled in the study. 1,800 of the cases reported using aspirin in the past while 1,200 of the controls reported using aspirin in the past.

Using the data given above, calculate the numeric value of this measure of association. The numeric value is...

Question

A case-control study was conducted to evaluate the relationship between aspirin use and the risk of colon cancer. 2,000 cases and 2,000 controls were enrolled in the study. 1,800 of the cases reported using aspirin in the past while 1,200 of the controls reported using aspirin in the past.

Using the data given above, calculate the numeric value of this measure of association. The numeric value is...

BlackTom AI · Accepted Answer

The problem provides a case-control setup with exposure data.
First, organize the data into a 2x2 table conceptually:
- Cases (n = 2000): 1800 exposed to aspirin, therefore 2000 - 1800 = 200 unexposed.
- Controls (n = 2000): 1200 exposed to aspirin, therefore 2000 - 1200 = 800 unexposed.

Next, compute the odds of exposure among cases and the odds of exposure among controls:
- Odds of exposure in cases = number exposed / number not exposed = 1800 / 200 = 9.
- Odds of exposure in controls = number exposed / number not exposed = 1200 / 800 = 1.5.

Then, calculate the odds ratio (OR), which is the ratio of these two odds:
- OR = 9 / 1.5 = 6.

Now, evaluate each answer option:
- Option 0.6: This is incorrect because the calculated OR is greater than 1 by a factor of 6, not 0.6. It would imply a protective effect, which contradicts the data.
- Option 6.0: This matches the computed odds ratio of 6, derived from (1800/200) divided by (1200/800).
- Option 0.2: This is incorrect; it would represent a very weak or inverse association, which does not fit the data given.
- Option 2.0: This is incorrect because the OR is not 2; the proper calculation yields 6, not 2.0.

In summary, the correct interpretation from the provided numbers is an odds ratio of 6, indicating higher odds of aspirin exposure among cases than controls in this dataset.

PUBHEPI 2410 AU2025 (1751) Quiz Module 7: Case-control studies

View Explanation

Log in for full answers

Similar Questions

In a cross-sectional study of the association between alcohol consumption and dementia, the most appropriate effect measure to calculate is:

Identify the bond angle and molecular shape of H2O.

Using Dalton's Atomic theory, explain the following observation. Hint: DO NOT answer with a law! The mass of the products at the end of the reaction was the same as the mass of the reactants at the beginning.

The number of valence electrons in a sulfur atom is 16.

If matter is uniform throughout and can be separated into multiple substances by physical means, it is called a(n) ________________.

Circle the letter for all examples of chemical change. Circle all correct answers.

Which of the following Lewis structures are incorrect? There may be more than one.

More Practical Tools for International Students

Exam Browser Assistant

Stylized Writing Assistant

Plagiarism Checker Assistant

Citation Assistant

In-Class Translation Assistant

Class Notes Assistant

Quiz Search Assistant

Past Exam Questions by School

Smart Practice Assistant

Adaptive Practice

Making Your Study Simpler