Hi Forum.
I am wondering if it is possible to compare two separate hazard ratios obtained from Cox models i.e. not a nested model, and obtain a p-value for comparison.
I came across a recent high impact journal publication where the authors state in their statistical methods: "Relative risks were expressed as hazard ratios with 95% confidence intervals derived from Cox models; hazard ratios for a positive FFRCT versus positive CTA were compared with the chi-square test." Link to paper: http://www.massgeneral.org/imaging/assets/pdfs/cardiac-mrpetct/lu-promise-ffrct-jacc-cvi-2017.pdf
How could this be done? My understanding is that chi-squared test is a global test, like the log-rank test; My take is that authors have done a 2x2 contingency table and obtained a p-value, but can you then extrapolate from this a comparison of hazard ratios? I did not think so because this is missing the time-to-event component.
Is this a valid method to perform?
Hi rakelren,
I've come across the same situation where I would like to compare HRs from two cox models. Except p value, I am also thinking of 95% CI. I did a lot of research but still don't know what to do. I am wondering if you have figured out?
Join us for SAS Innovate April 16-19 at the Aria in Las Vegas. Bring the team and save big with our group pricing for a limited time only.
Pre-conference courses and tutorials are filling up fast and are always a sellout. Register today to reserve your seat.
ANOVA, or Analysis Of Variance, is used to compare the averages or means of two or more populations to better understand how they differ. Watch this tutorial for more.
Find more tutorials on the SAS Users YouTube channel.