Post-hoc power analysis for Cox regression

Manije72 — Tue, 30 Jan 2024 23:17:48 GMT

Hi,

I want to do post hoc power analysis for Co regression. I want to calculate power in SAS for cox regression. I can find the hazard ratio and confidence interval from other studies. How can find R square and standard deviation for these code

proc power;
coxreg
hazardratio = 1.4
rsquare = 0.15
stddev = 1.2
ntotal = 80
eventprob = 0.8
power = .
;
run;

Re: Post-hoc power analysis for Cox regression

ballardw — Tue, 30 Jan 2024 23:36:20 GMT

Proc Power is intended to do pre-study planning, not post hoc power analysis.

From the online help:

Overview: POWER Procedure

Power and sample size analysis optimizes the resource usage and design of a study, improving chances of conclusive results with maximum efficiency. The POWER procedure performs prospective power and sample size analyses for a variety of goals, such as the following:

determining the sample size required to get a significant result with adequate probability (power)

characterizing the power of a study to detect a meaningful effect

conducting what-if analyses to assess sensitivity of the power or required sample size to other factors

(my color emphasis added)

topic Re: Post-hoc power analysis for Cox regression in Statistical Procedures

Post-hoc power analysis for Cox regression

Re: Post-hoc power analysis for Cox regression

Overview: POWER Procedure