Twice this afternoon (1-26-15) I received a call from 202-759-1595.  The first time the phone rang twice and stopped before a third ring.  The second time, a hour or so later, it rang again and I answered between the first and second ring tone.  A recorded message said simply, "This is the Doctors Network.  Press 1 if you would like to be removed from our call list."  I just waited.  The recorded message played again....and again after another wait.   No reputable firm would say this without at least giving a reason for the call.  I am wary of responding in any form and find it distracting to receive such calls.