Sample size calculation for Cox regression using the software PASS

This video is showing how to do a sample size calculation for Cox regression using the software PASS. In the example we are looking for healing of a diabetic wound. We estimate that 70% of patients will heal their wounds during the time we observe them. We estimate that the variable being one decade older as a patient reduces the probability of healing (having a Hazard ratio of less than 1). By reading previous publications we estimate the Hazard ratio for being one decade older to be 0.9. We specify that power should be 0.9 and alpha (the p-value we want to obtain if the hazard ratio really differs from random variation) should be 0.05. More about sample size estimations on: science-network...

[@mdnrp7040]

Thanks for your presentation, but I want to ask how to do with categoric parameters in cox regression?

[@hemantmahajan3309]

what about binary variable?