Power Calculation and Number of Subjects Needed for a Study

[Yughaber]

Hello, 

I am in great need of some guidance towards power calculation. I need to calculate the number of minimum subjects needed for a specific research study and the power of that study. I looked into proc power but am still a bit unsure of the whole thing and would appreciate some insight. 

The research is pretty simple and basic. I have two groups undergoing the same surgery but patients in each group are being treated with a different drug (drug A and drug B respectively for each group), I would like to see if drug A is better than drug B. I am using a t-test for this comparison of means. 

Thanks! 

[Reeza]

Looks like two sample means, possibly one sided?
https://support.sas.com/resources/papers/proceedings15/SAS1911-2015.pdf

[SteveDenham]

One thing to consider is the distribution of your response variable - continuous, count, proportion - as all need to handled a bit differently in PROC POWER.

SteveDenham

[Yughaber]

is there maybe a reference/resource I can learn from for this specific point?

[SteveDenham]

The PROC POWER documentation is an excellent place to start for power and sample size calculations.  For distributions, it is hard to beat Merran Evans Statistical Distributions.

SteveDenham