Sample size & Power Question 2

Question

Use the figure below to indicate whether the following statements are true or false:

Figure 12-7 Source: Aschengrau and Seage 3rd edition Chapter 12. Power curves for a Cohort Study with an Equal Number of Exposed and Unexposed Subjects (alpha error is 0.05; outcome frequency is 0.10)


A) Power curve #1 has a higher minimum detectable effect than power curve #2


B)  With a fixed sample size of 100 subjects, a study with a larger effect size will have higher power. Assume all other parameters of the study are equivalent.


C) With a fixed risk ratio of 2.0, a study with 100 subjects will have higher power than a study with 200 subjects. Assume all other parameters of the study are equivalent.


D) If the effect size of interest decreases, the sample size needed to maintain power of 80% will increase. Assume all other parameters of the study are equivalent.



E) If minimum detectable effect decreases and sample size remains constant, power will decrease. Assume all other parameters of the study are equivalent.

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