I work at a company that does applied machine learning and health care is the #1 source for prospective business. The hardest part isn't the analysis - it's getting good, valid data. Health care data is so sparsely collected, poorly structured (if at all) and the privacy issues surrounding gaining access are very strict (perhaps rightfully so).<p>The key, as IBM is doing, if working with a large HMO or health care network who hopefully have switched to a sensible EMR and have built up a good amount of historical data on patients.<p>I'd add one last key to getting this right isn't only the breadth of the data, but the depth. Knowing some superficial aspects of a person (age, weight, habits) is too naive. You need family history, you need psychosocial aspects (nightmares, trouble at work, marital problems etc.). If you can get <i>that</i>, then you're cooking.