［USA］:Diffusion of Innovation

New York Timesの特集、Class Mattersの企画中、JANNY SCOTTは医療の利用可能性が患者本人の経済的境遇によって著しく制限されてしまう場合があると説く。
　極端な場合、心臓発作に襲われた直後でも、次の二つのタイプのうちどちらの病院に自らが搬送されるべきなのかを救急車のなかで選択しなければならないのだという：やや距離がある安い州立の市民病院か、もしくは、値は張るがその分治療も丁寧な私立の病院か。（May 16, 2005 Life at the Top in America Isn't Just Better, It's Longer ）

''In the last 20 years, there have been enormous advances in rescuing patients with heart attack and in knowledge about how to prevent heart attack,'' said Ichiro Kawachi, a professor of social epidemiology at the Harvard School of Public Health. ''It's like diffusion of innovation: whenever innovation comes along, the well-to-do are much quicker at adopting it. On the lower end, various disadvantages have piled onto the poor. Diet has gotten worse. There's a lot more work stress. People have less time, if they're poor, to devote to health maintenance behaviors when they are juggling two jobs. Mortality rates even among the poor are coming down, but the rate is not anywhere near as fast as for the well-to-do. So the gap has increased.''