Sample size calculation: Bland-Altman plot

[ammarhm]

Hi everyone,

could anyone please tell me how to do a sample size calculation for the difference between 2 lab tests? see this link for further info on what I want to do

https://www.medcalc.org/manual/sampling_blandaltman.php

Thank you

AM

[FreelanceReinh]

Hi @ammarhm,

Luckily, the full text of the paper containing the sample size formula is only three mouse clicks away from the MedCalc web page you refer to. The formula is not given in closed form, though. But even if you don't have a SAS/OR license to solve this equation, you can still use a Base SAS implemented solver. I have had positive experiences with macro %Bisect, which is presented in this SESUG 2007 paper.

[ammarhm]

Thanks @FreelanceReinhard. I appreciate your time writing a reply to my question, and I hope you (or anyone else) dont think I am being rude here, but honestly, i am not sure how to use your reply in answering my question...

[FreelanceReinh]

1. Did you find the paper Lu et al. (2016) containing the sample size formula?
2. Since you are going to do a sample size calculation, I hope that you can make sense of a sample size formula. Or are you only familiar with point-and-click tools for sample size calculation?