What aspect of effective communication do you think is most important in the health sciences?

Let's all think about "Health Sciences" for a second. If any of you don't know what this means..it pertains to the field of medical primarily. With that in mind, you NEED to have effective means of communication in this field for many reasons of which some include: patient medical record accuracy, medication accuracy, diagnosis accuracy.

You wouldn't want to go into the emergency room at the hospital because you broke your toe and then all the sudden you are being taken to surgery for a procedure that is taking place on you left L5-S1 (lumbosacral spine). Or perhaps due to inadequate communication processes you could accidently be billed for a procedure that you didn't have and the next thing you know you have a bill in the mail from your health insurance provider stating you owe $23,000 for the procedure that they did not cover. Things like this could happen if you do not practice effective communication in this field.