Without context this is hard to say --- I will point you to the relevant literature so you can get started. It seems that what you want to do is related to the *data fusion* problem --- how to combine data of different settings and interventions. You can read the papers by [Elias Barenboin][1], [specially this one with Pearl.][2]




  [1]: https://www.cs.purdue.edu/homes/eb/
  [2]: http://ftp.cs.ucla.edu/pub/stat_ser/r450-reprint.pdf