In the early days of the 20th century, department store magnate John\nWanamaker famously said, “I know that half of my advertising doesn’t\nwork. The problem is that I don’t know which half.” That remained\nbasically true until Google transformed advertising with AdSense based\non new uses of data and analysis. The same might be said about health\ncare and it’s poised to go through a similar transformation as new\ntools, techniques, and data sources come on line. Soon we’ll make\npolicy and resource decisions based on much better understanding of\nwhat leads to the best outcomes, and we’ll make medical decisions\nbased on a patient’s specific biology. The result will be better\nhealth at less cost.\nThis paper explores how data analysis will help us structure the\nbusiness of health care more effectively around outcomes, and how it\nwill transform the practice of medicine by personalizing for each\nspecific patient.