Dear All,
I am a vascular surgeon planning a research project.
I need some advice regarding the sample size calculation.
I am looking at the same group of patients pre and postprocedure looking for a change in the diameter of their main blood vessel at 2 different points.
We have some data from a small pilot study published;
Pre post Range for post n
Point 1: 27.4mm 28.3mm 25.24  21.83 43
Point 2: 22.2mm 23.6mm 21.83  29.76 43
I have worked out the sample size in the attached image, can someone please confirm if this calculation is correct?
Do I need to add the two sizes or use the bigger of the two?
Thanks in advance.
Dr Sobath Prem
I am a vascular surgeon planning a research project.
I need some advice regarding the sample size calculation.
I am looking at the same group of patients pre and postprocedure looking for a change in the diameter of their main blood vessel at 2 different points.
We have some data from a small pilot study published;
Pre post Range for post n
Point 1: 27.4mm 28.3mm 25.24  21.83 43
Point 2: 22.2mm 23.6mm 21.83  29.76 43
I have worked out the sample size in the attached image, can someone please confirm if this calculation is correct?
Do I need to add the two sizes or use the bigger of the two?
Thanks in advance.
Dr Sobath Prem
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