Two-thirds of Americans say they are willing to anonymously share their health information with researchers, but only about 1 in 5 is willing to provide their purchase history or social media activity, according to a recent Truven Health Analytics-NPR Health Poll. The findings suggests that while there is growing comfort with electronic health records, privacy concerns may hinder the ability of Big Data to deliver on its full promise to improve the health of individuals. We spoke to Michael Taylor, chief medical officer of Truven Health Analytics, about the survey, the level of theft and misuse of health data, and who people trust the most with their information.