患病人数英语

这个问题太专业，下列信息皆摘自网上，仅供参考，同时要谢谢你的提问让我学到了更多的内容。Prevalence is a frequently used epidemiological measure of how commonly adisease or condition occurs in a population. Prevalence measures how much ofsome disease or condition there is in a population at a particular point in time.The prevalence is calculated by dividing the number of persons with the diseaseor condition at a particular time point by the number of individuals examined.For example, in the study above 6139 individuals completed the questionnaire(were examined). Of these 6139 people, 519 currently suffered incontinence andso had the condition at the particular time point of the study. Thus theprevalence of incontinence was 519/6139 = 0.085.Prevalence is often expressed as a percentage, calculated by multiplyingthe ratio by 100. The above study expresses prevalence as a percentage, thusthe prevalence of incontinence is 8.5% (or rounded is 9%). Another commonway of expressing prevalence, particularly if the prevalence is low, is as thenumber of cases per 100,000 of the population. For example, it is easier tostate the result as `66 cases per 100,000 people' than to say the prevalence is0.00066. Le and Boen (1995) provide further examples of the calculation ofprevalence.The incidence of a disease is another epidemiological measure. Incidencemeasures the rate of occurrence of new cases of a disease or condition.Incidence is calculated as the number of new cases of a disease or condition ina speci®ed time period (usually a year) divided by the size of the populationunder consideration who are initially disease free. For example, the incidenceof meningitis in the UK in 1999 could be calculated by ®nding the number ofnew meningitis cases registered during 1999 and dividing that number by thepopulation of the UK. As this incidence rate would be very small again wetend to consider number of cases per 100,000 people.区别：患病率(prevalence rate)：也称现患率。指某特定时间内总人口中某病新旧病例所占比例。可按观察时间的不同分为期间患病率=某观察期间一定人群中现患某病的新旧病例数/同期的平均人口数(被观察人数) ´K和时点患病率=某一时点一定人群中现患某病新旧病例数/该时点人口数(被观察人数) ´K。K= 100%，1000/千，或10000/万。期间患病率实际上等于某一特定期间开始时患病率加上该期间内的发病率。患病率通常用来表示病程较长的慢性病的发生或流行情况。如冠心病、肺结核等。可为医疗设施规划，估计医院床位周转，卫生设施及人力的需要量，医疗质量的评估和医疗费用的投入等提供科学的依据。发病率(incidence rate)： 表示在一定期间内，一定人群中某病新病例出现的频率。发病率=一定期间内某人群中某病新病例数/同时期暴露人口数 ´K，（K= 100%， 1000/千，或 10000/万）。观察时间多以年表示。分子与分母的确定：分子是一定期间内的新发病人数。若在观察期间内一个人可多次患病时，则应分别计为新发病例数。分母中所规定的暴露人口是指可能会发生该病的人群。发病率可按不同特征(如年龄、性别、职业、民族等)分别计算，此即发病专率。用作描述疾病的分布，通过比较不同人群的某病发病率来帮助确定可能的病因，探讨发病因素，提出病因假说，评价防治措施的效果。发病率的准确性取决于疾病报告，登记制度以及诊断的正确。联系：患病率取决于发病率和病程。患病率的变化反映出发病率的变化或疾病结果的变化或两者兼有。患病率水平(所有病例)随着发病率(新病例)增高而增高，并随着疾病恢复的加速或死亡的加速而下降。某地某病发病率和该病的病程在长时间内保持稳定时，患病率=发病率´病程，即：P=ID。