The prevention challenge and opportunity.

In the United States, more money is spent on treating diseases and their complications than on preventing them in the first place. Prevention is both undervalued and poorly supported in our health system. In this Perspective I discuss how the McKinlay model can be used to illustrate the three levels at which we need to increase our investment in prevention. I recognize the many challenges in implementing programs of prevention, but I also note that these programs represent opportunities to improve health, prevent unnecessary pain and suffering, and, in time, develop a health system that is balanced and affordable.