Question
A study claims that the combination of vitamin C with vitamin E is more effective for preventing the flu than vitamin C alone. In the study, a group of researchers studied 1132 subjects. The subjects were randomly assigned to one of three study groups. The first group of 310 subjects were instructed to take 600 mg daily of vitamin C. The second group of 418 subjects were instructed to take 600 mg of vitamin C and 200 IU of vitamin E daily. The third group of 404 subjects were instructed to take 600 mg of vitamin C and 400 IU of vitamin E daily. The incidence of flu over a season was recorded. All subjects knew which treatment they were receiving. In this study, which is the control group? A The second group of 418 taking 200 IU of vitamin E B The first group of 310 taking vitamin C alone C The third group of 404 taking 400 IU of vitamin E D The 1132 subjects E There is no control group. This study is A not blind B not an experiment C double-blind D blind, but not double-blind E none of the above
Ask by Valdez Ortiz. in the United States
Jan 16,2025
Real Tutor Solution
Tutor-Verified Answer
Answer
- **Control group:** B. The first group of 310 taking vitamin C alone
- **Study is:** A. not blind
Solution
**Control Group:**
The control group in a study is typically the group that receives the standard treatment or no treatment, serving as a baseline to compare the effects of other treatments. In this study:
- **First Group:** Takes 600 mg of vitamin C alone.
- **Second Group:** Takes 600 mg of vitamin C + 200 IU of vitamin E.
- **Third Group:** Takes 600 mg of vitamin C + 400 IU of vitamin E.
Since all groups are receiving vitamin C, the first group (taking only vitamin C) serves as the control group to evaluate the added effect of vitamin E in the other groups.
**Answer:**
**B. The first group of 310 taking vitamin C alone**
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**Study Design:**
The study mentions that **all subjects knew which treatment they were receiving**, meaning there was no blinding involved. Blinding is essential to prevent bias, and since the participants were aware of their treatment, the study is **not blind**.
**Answer:**
**A. not blind**
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**Final Answer:**
- **Control group:** B
- **Study is:** A
**Answer:**
- **Control group:** B
- **Study is:** A
Reviewed and approved by the UpStudy tutoring team
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Simplify this solution Bonus Knowledge
In this study, the control group is the second group of 418 subjects who were instructed to take 600 mg of vitamin C and 200 IU of vitamin E daily. This group serves as a basis for comparison against the other treatment groups to evaluate the effectiveness of the additional Vitamin E. This study is not blind. All subjects were aware of which treatment they were receiving, introducing a potential bias in their self-reporting or behavior. A blind study keeps participants unaware of their group allocation, which helps improve the reliability of the results.
