1 reply to this topic

[Jon Griffin]

Hi

 

I am performing a PK/PD analysis using Phoenix 7.0 and have fitted a Sigmoidal Emax model with Dose vs PD effect and would like to also have an estimate of the EC / ED80, as well as the EC / ED50 that is already presented as a parameter, for predicting a range of doses. Can anybody help with adding this?

 

Thanks

Jon

Edited by Jon Griffin, 27 June 2017 - 11:21 AM.

[Simon Davis]

Hi Jon - if you search the forum you'll find the related time about EC90;

 

https://support.cert...models/?hl=ec90

 

It states that ....

If EC50 and n are known, a general equation to calculate ECF, where F is any percentage, is

ECF = ((F/100-F)^(1/n)*EC50))

 

So I think for your ED80, add the following line to the code to calculate from the textual sigmoidal Hill Emax model:

 

secondary(ED80 = ((80/(100-80))^(1/n) * EC50))

 

The ED80 calculated from this equation will appear in the output worksheet named Secondary.

 

  Simon