by Darren WilcoxAt the core of our nation's health-care crisis is the rapid growth in costs. At the core of any solution, then, is reducing those costs so that the 46 million Americans without insurance today have access to affordable coverage.So what drives up the cost of health care? Research shows that 50 to 70 percent of all health-care costs are caused by behavior and by chronic diseases like diabetes, hypertension, and heart conditions. By simply lowering obesity rates, for example, we could avoid $60 billion in annual medical costs and gain back $254 billion in productivity.More than half of all Americans suffer from one or more chronic conditions that are closely tied to behavior. Prevention and wellness programs, meanwhile, give people incentives to improve their habits and their health. Whether it's installing an exercise facility at an office, providing financial rewards for smoking-cessation efforts, or developing a product to help patients better manage their care, there are countless creative programs that can be designed. Many businesses across this country have started such efforts, and the result is lower costs and better health. We need to ensure that this concept becomes part of any reform plan on the national level.Wilcox is the executive director of the Coalition To Advance Healthcare Reform. He thinks we should base health-insurance premiums on user behavior.