question archive Recently it has been observed that HIV infected patients develop peripheral lipoatrophy while on potent antiretroviral therapy
Recently it has been observed that HIV infected patients develop peripheral lipoatrophy while on potent antiretroviral therapy
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Recently it has been observed that HIV infected patients develop peripheral lipoatrophy while on potent antiretroviral therapy. A clinical trial is planned to determine whether a new chemical will improve this condition. In the trial, participants will be randomized to receive the new chemical or a placebo, and changes from baseline in subcutaneous adipose cross-sectional area as measured by CT scan will be calculated after 24 weeks of treatment. Investigators hope to show that the increases in patients receiving the chemical will be greater than the increases in patients receiving the placebo. They hypothesize that the participants assigned to the chemical arm will exhibit a mean change of 30% and that the participants assigned to the placebo arm will exhibit a mean change of 0%. Prior literature suggests that the standard deviation of the changes will be 57% in both arms. How many participants are needed to ensure 80% power? Assume that α = 0.05, that there are equal numbers in each group, and that 20% of the participants will drop out over the course of follow-up.
