Hi all,

I'm comparing the effect of different therapeutic methods on the one year survival rate of different groups of patients. I calculated Hazard ratio (HR) using this formula:

HR= [Ln(proportion of patients event-free on research arm)] /  [Ln(proportion of patients event-free on control arm)]

Also, I calculated Standard error (SE) of HR in different studies based on availability of data such as; confidence interval (CI) , p-value and number of patients at risk.

Unfortunately, in some studies, none of this information is available. So I wonder if you could help me with an alternate method to calculate SE using HR.