In a prospective cohort study of 14 357 participants (282 097 person-years) free of stroke at baseline in US communities, stroke incidence and mortality rates decreased from 1987 to 2011. The decrease in age-adjusted incidence was evident in participants age 65 years and older. The decrease in mortality was mostly accounted for by the decrease at younger than age 65 years. The decreases in stroke incidence and mortality rates were similar across race and sex. Better control of risk factors (hyperlipidemia, hypertension, and smoking, etc.) may largely explain the lower stroke rate among people over the age of 65, while the rise in obesity and diabetes in younger adults could explain the lack of progress in reducing stroke incidence in younger adults. Source: http://jama.jamanetwork.com/美国社区的一项包括14357人（282097人 – 年）无卒中人群的前瞻性研究表明，从1987年到2011年脑卒中的发病率和死亡率均下降。经年龄校正的发病率在年龄65岁及以上的参与者中明显降低。死亡率的下降则主要是在年龄小于65岁者。中风发病率和死亡率的下降无种族和性别差异。危险因素（高脂血症，高血压，吸烟等）得到更好地控制在很大程度上可以解释年龄超过65者中风发病率下降，而在较年轻的成年人中肥胖和糖尿病的增加可以解释在较年轻的成年人降低中风发病率方面缺乏进展。来源：http://jama.jamanetwork.com/
