This is second time I have received this phone call, on 3/13 and today 3/20; caller ID states caller is Doctors Group. Research on the internet revealed the call to originate in Charlotte, NC.  The caller said this is for a medical screening service, and when would be a good time for me to come in for medical screening.  I declined, and hung up.  Next time I receive this call, I am going to ask questions.