Separating GPO spin from substance is difficult. For example, based on group purchasing organization-reported data, the General Accounting Office ranked the top seven national GPOs anonymously based on purchasing volume in 2002. All told, the seven GPOs accounted for more than 85%-$43 billion-of all hospital purchases nationwide, according to the GAO.
But don't bother trying to figure out which is which by comparing the list against a similar one compiled by NCI, a Palm Harbor, Fla., consulting company specializing in the healthcare purchasing business. The seven purchasing volume numbers from NCI, likewise self-reported by the GPOs, are essentially unrecognizable from the GAO's list and add up to a $13 billion discrepancy in total purchasing volume for, presumably, the same seven GPOs (See charts).
It all depends on how you ask the question. Some GPOs calculate purchasing volume by including supplies sold under contract as well as supplies that go through a distributor, resulting in some overlap. MedAssets, for instance, uses a number it calls "through-put," which measures the total purchasing volume of its members-what they spend on supplies, says Gary Johnson, MedAssets' vice president of marketing and marketing services. The number is calculated by adding two separate data files, and there is some overlap, he says.
The lesson: Every GPO has its own unique way of crunching the numbers.
"I think all numbers should be taken with a grain of salt," Johnson says.