Founded an early data management tool for physician "decision support." While practicing cardiology in New York City in the 1980s and 1990s, Dr. Riesman moonlighted as a health benefits consultant for Merrill Lynch & Co., and later joined William M. Mercer. Dr. Reisman went out on his own to found ActiveHealth in 1998, and built the ActiveHealth CareEngine. Sold as a service into plans and employers, the engine gathers data from a patient's claims, lab tests or pharmacy-fills, to inform a physician of the best (or warn of the worst) therapy, according to available medical evidence. Purchased by Aetna in 2005, ActiveHealth partners with American Well, and is a key component of Microsoft's in HealthVault.

Chatting with Esther Dyson:

“Much of the talk now is about assembling all the data on a patient – dealing with data standards and getting all the data into a single record. But that’s not enough. What’s the difference if I have piles of paper in a folder, or a fancy Web interface, or even nothing at all? If I don’t have the time to look at it for each patient, it might as well not be there. You need to analyze and apply the data as well – the patient-specific information matched to the best-practice rules that not every doctor can know in every specialty."