Sample Size for Survival Analysis

 

Menu location: Analysis_Sample Size_Survival Times.

 

This function gives you the minimum number of subjects that you require to detect a true ratio of median survival times (hr) with power POWER and two sided type I error probability ALPHA (Dupont, 1990; Schoenfeld and Richter, 1982).

 

The method used here is suitable for calculating sample sizes for studies that will be analysed by the log-rank test.

 

Information required

 

Practical issues

 

Technical validation

The estimated sample size per group n is calculated as:

- where α = alpha, β = 1 - power and zp is the standard normal deviate for probability p. n is rounded up to the closest integer. (1+1/m)/p is equivalent to 2/p in the first equation if the experimental and control group sizes are unequal.

 

 

Copyright © 2000-2017 StatsDirect Limited, all rights reserved. Download a free trial here.