You are planning a case-control study of lung cancer to test the hypothesis that vegetable consumption is protective against lung cancer. Would you match on smoking? Explain your answer.
- A. Yes, because smoking is a known confounder for lung cancer.
- B. No, because matching on smoking will introduce overmatching.
- C. Yes, because smoking correlates with vegetable consumption.
- D. No, because smoking is unrelated to vegetable consumption.
Correct Answer: A
Rationale: Smoking is a strong confounder for lung cancer, and matching on smoking helps ensure comparability between cases and controls, preventing spurious associations.
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The true regarding chi square test:
- A. Null hypothesis is equal
- B. Does not test the significance
- C. Tests correlation and regression
- D. Measures the significance of difference between two proportions
Correct Answer: D
Rationale: Chi-square tests assess differences between observed and expected frequencies.
Name the four major classes of pesticides.
- A. Organochlorines, organophosphates, carbamates, pyrethroids.
- B. Antibiotics, antifungals, herbicides, rodenticides.
- C. Insecticides, fungicides, herbicides, acaricides.
- D. Biological agents, synthetic agents, natural agents, chemical agents.
Correct Answer: A
Rationale: The four major classes of pesticides are organochlorines, organophosphates, carbamates, and pyrethroids.
A wide range of values can be plotted and seen clearly, regardless of magnitude
- A. Arithmetic-scale line graph
- B. Semilogarithmic-scale line graph
- C. Both
- D. Neither
Correct Answer: B
Rationale: Semilogarithmic-scale line graphs accommodate wide value ranges effectively.
The hallmark feature of an analytic epidemiologic study is:
- A. Use of an appropriate comparison group
- B. Laboratory confirmation of the diagnosis
- C. Publication in a peer-reviewed journal
- D. Statistical analysis using logistic regression
Correct Answer: A
Rationale: The key feature of analytic studies is the use of a comparison group to assess associations.
Precision stands for—
- A. Reliability
- B. accuracy
- C. consistency
- D. validity
Correct Answer: A
Rationale: Precision denotes the reliability and consistency of measurements.