My computer vendor is using C/T to calculate a CTU ratio. Problem is all data containing a zero comes out to 0 for the ratio. I am trying to convince them perfection is 1:1 or 1, and 0 should not be a result. Also, that using their formula results in a physician that never uses the blood they order having the lowest result. Also, if a physician orders 4 units and uses one, their formula results in a CT = 4.0. They do not understand. Anyone have a mathematical formula that can be used to calculate a CTU ratio? Thanks.