问题 单项选择题

下列哪一项不是病例对照研究的特点()

A.省力省钱

B.适合于罕见病的研究

C.可从所得结果估计相对危险度

D.可直接计算归因危险度

E.选无本病者作为对照

答案

参考答案:D

解析:此题为理解判断题。归因危险度是暴露组与非暴露组人群发病率或死亡率之差,病例对照研究无法得到发病或死亡的频率,故无法计算归因危险度。

单项选择题

My Space and other Web sites have unleashed a potent new phenomenon of social networking in cyberspace, (1) at the same time, a growing body of evidence is suggesting that traditional social (2) play a surprisingly powerful and under-recognized role in influencing how people behave.

The latest research comes from Dr. Nicholas A. Christakis, at the Harvard Medical School, and Dr. James H. Fowler, at the University of California at San Diego. The (3) reported last summer that obesity appeared to (4) from one person to another (5) social networks, almost like a virus or a fad. In a follow-up to that provocative research, the team has produced (6) findings about another major health (7) : smoking. In a study published last week in the New England Journal of Medicine, the team found that a person’s decision to (8) the habit is ply affected by (9) other people in their social network quit—even people they do not know. And, surprisingly, entire networks of smokers appear to quit virtually (10)

For (11) of their studies, they (12) of detailed records kept between 1971 and 2003 about 5,124 people who participated in the landmark Framingham Heart Study. Because many of the subjects had ties to the Boston suburb of Framingham, Mass. , many of the participants were (13) somehow—through spouses, neighbors, friends, co-workers—enabling the researchers to study a network that (14) 12,067 people.

Taken together, these studies are (15) a growing recognition that many behaviors are (16) by social networks in (17) that have not been fully understood. And (18) may be possible, the researchers say, to harness the power of these networks for many (19) , such as encouraging safe sex, getting more people to exercise or even (20) crime.

20()

A.banning

B.promoting

C.fighting

D.committing

单项选择题