流行病与卫生统计学 05病例对照研究.pptVIP

思考题 病例对照研究的基本原理与特点？ 对照组选择的基本原则？ 匹配的目的？ 比值比（OR） 病例对照研究与队列研究的优缺点比较？ 成组资料与配对资料的分析？ 何谓偏倚？主要有哪几种类型？ * 参考书目： 1. 流行病学. 医学院校预防医学专业本科教材. 人民卫生出版社. 2. 王天根, 主编. 流行病学方法. 北京: 北医协和联合出版社, 1995. 2. Breslow NE, Day NE. Statistical methods in cancer research: Vol1-The analysis of case-control studies. IARC Scientific Publications, No. 32. 1980. * 病例对照研究用于探索两种现象之间的因果关系。除研究疾病的病因以外，还可广泛用于研究伤害和各种与健康有关事件的危险因素。 * 疾病严重程度、患者经济状况、就诊方便与否都会影响入院率 * Let’s look at another example. Here is a picture of my daughter, Sonia, with her Winnie the Pooh nightlight. We found having this nightlight was very helpful to us when it came to navigating around her room at night. * We kept the nightlight on until we read the now famous study in Nature from my Alma Mater, the University of Pennsylvania, which strongly suggested that ambient nighttime lighting before age 2 was associated with the occurrence of nearsightedness in children. Here kids who used nightlights were over 3 times more likely to have myopia. * So, off went the nightlight and we began to stumble around her room. * Until two subsequent studies came out, again in Nature, showing no association. * These authors believed that the apparent association use of a night light and child’s myopia was likely because of confounding by parent’s myopia. These authors provided direct data that nearsightedness in parents is associated with the use of night light, probably to help the parents see better. And, there is data to suggest that myopia is inherited; ie if parents have it, their kids are more likely to have it. So, this is an example, where parenteral myopia confounds the relationship between night lights and child’s myopia and there is no real direct, or what we call independent, association between use of night lights and child’s myopia. * So, our fears relieved about night lights. . .. on comes the night light again and everyone is happy. * 匹配后还得再分层，否则会引入混杂 或者不匹配，只分层，可以控制混杂 * 分层分析 SPSS SPSS (1) (2) (3) (1) (1) (2) OR40=2.80, OR?40=2.78, 经检验