Nearly a year and a half after Microsoft launched its HealthVault personal health record platform, it cannot supply a list of the healthcare providers who are uploading clinical data to HealthVault, said Peter Neupert, corporate vice president of Microsoft’s Health Solutions Group, in a call-in conference with healthcare bloggers. That’s partly because many providers are uploading data through their software vendors, he said. He also admitted that doctors and hospitals are still sussing out whether they want to share patient data, and how they should go about doing it.