社区获得性肺炎(CAP)是最常见的感染性疾病之一,普通人群中的年患病率为0.5%~1.1%,其中约80%的CAP患者在门诊接受治疗,只有20%的患者需要住院治疗[1]。无论在发达国家还是发展中国家,CAP都造成了巨大的社会经济负担,美国每年治疗CAP的相关费用高达170亿美元[1]。合理应用抗菌药物,采用高性价比的治疗方案是减轻CAP相关医疗卫生支出的重要环节。由于80%以上CAP Community acquired pneumonia (CAP) is one of the most common infectious diseases, with an annual prevalence of 0.5% to 1.1% in the general population, of whom about 80% of CAP patients are treated in an outpatient setting and only 20% of patients require Hospitalization [1]. In both developed and developing countries, CAP has caused tremendous socioeconomic burdens. The cost of CAP treatment in the United States is as high as 17 billion U.S. dollars each year [1]. Rational use of antimicrobial agents, the use of cost-effective treatment programs to reduce CAP related health expenditure an important part. As more than 80% CAP