Hello all, I am a SAS Studio student, and I am having trouble with this homework problem. I do not know which procedure to use for this. I'd greatly appreciate any advice. Thanks in Advance! For determining sample size estimates for time dependent (survival) data, usually the number of estimated events (D) (e.g. deaths, rejections, relapse, reops, etc.) must first be calculated. Once that is established, the total sample size (n) may be derived based on the percentage of patients that remain event-free at the end of the study. The two equations for D and n are found below. These equations are for the (Parametric) version of sample size determination for Survival Data or Time to Failure data. D = total # of events required α = Z critical value - Type I error Β = Z critical value - Type II error Δ = hazardratio =λΤ/λc = lnπT /lnπC n=D Example: 90% Power Δ = 2.0 1 - %event-free D=4(1.96 + 1.282)^2/[ln2]^2= 87.5= 88 events This assumes that all participants will be followed until their event. Suppose that previous studies suggest that 30% of subjects remain event-free at the end of trial. Then, sample size n n = D/1 - %event-free = 88 / (1-0.30) = 125.7 = 126 This number might be further inflated to account for dropout, but we won’t worry about that here. In SAS, write code to calculate D and n for the following scenarios: When alpha = 0.05 and the hazard ratio may be either 2.0 or 1.5, for power = 0.8 and also for power = 0.90. And either 30% or 20% of subjects remain event-free at the end of trial. Do you see that you will have 8 pair of estimates for D and n in your output? Please include your SAS code. Your estimate for D and n should be in integer form. Note: Power Z(subscript B) 80% 0.84 90% 1.28
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