ProPublica, the nonprofit news organization, reports that  the U.S. Supreme Court has dealt a blow  to  efforts to track the quality and cost of health care, “ruling that a 1974 law precludes states from requiring that every healthcare claim involving their residents be submitted to a massive database”.

“The arguments {in the Vermont case} were arcane, but the effect is clear: We’re a long way off from having a true picture of the country’s healthcare spending, especially differences in the way hospitals treat patients and doctors practice medicine.”

ProPublica also reported that the ruling means “for the time being at least, we’ll remain heavily reliant on data being released by Medicare.”

News organizations have used Medicare data to study differences in medication prescribing, surgeons’ complication rates and use of services by doctors, but it’s still not clear that Medicare is representative of all  U.S. healthcare.