Best hospital price is determined based on the other prices that a hospital was offered for the item in question at the time of purchase, given that the item was available at the other vendor options. If it was cheaper somewhere else, we report missed savings as the price paid minus that cheaper price.
Best corporate price is determined (essentially) by the best price any hospital in your group is being offered by any distributor for that given item. We take the difference between this and the price paid and report that as missed savings. We don’t survey the complete list of prices that are offered, but rather a carefully selected subset of hospital and vendor combinations that we believe will have the highest likelihood of receiving the best pricing for that item. Because of this, the best corporate price may at times be an underestimation of the true value, but with high probability it’s accurate.