Question

9. When you desire to study the effects of a rare exposure on a disease using observational methods, you would optimally employ the type of study design. Remember you would likely need to conduct your study in a place where the exposure occurs. cohort b ase-control 10. Another name for a retrospective study is an) study b. cohort e experimental 11. You have completed a year long study of the effectiveness of a reading program among second graders. At the beginning of the year the students were reading at the 99th percentile nationally. These are very good students! A test at the end of the year indicated they were only reading at the 95nd percentile. The principal concludes that the teacher did not do a good job of teaching because his/her students scored 4% points lower than at the beginning of the year. The principal does not want to give the teacher a pay raise. What threat to internal validity would you tell the principal might have affected the results? History Maturation Testing Regression toward the mean c. Instrumentation Attrition Selection 12. Assuming no misclassification of subject disease status, the disease prevalence in the "case" group, in a case-control study a is always 0% b. is always 100% c. can be any % 13. If you read in a scientific journal, "We conducted a randomized clinical trial."you know the design of the study being described is the type. a case-control b. cohort e. experimental 14. A statistic that is used by health educators to identify the excess disease occurrence in the high-risk group is a relative risk b. odds ratio c. attributable risk d. correlation 15. True False The relative risk statistic which can be garnered from the cohort design is a comparison of the incidence rates among the exposed the high risk group) with the incidence rates among the unexposed (also called the low risk) group. 16. True False in using the case-control study design researchers should be especially alert to the possibility of recall bias, because that type of bias could affect results. 17. You read the following in a scientific journal: "Subjects were randomly assigned into one of two groups. One group of subjects received a new drug treatment and the remaining subjects received the placebo." What type of study design is being described? A. Cohort B. Case-Control C. Experiment 18. In epidemiology the etiologic fraction is another name for the a relative risk b. odds ratio c. attributable risk statistic.

Answer 1

No 9. When you desire to study the effects of a rare exposer it always bests that, you should choose the cohort study.

A cohort study is also known as an observational study.

You can observe the exposure in the place you want but in a case-control study, you can not do that because you have to follow the disease.

In case-control study It always best to study rare diseases but not rare exposure.

So, the answer is the Cohort study

No 10

A Case-control study is also known as a retrospective study. Because here in the case-control study you look backward disease to the risk factor.

Cohort study can be retrospective or can be prospective or experimental study is always prospective.

So, the answer is Case-control study

No 11.

At the beginning of the study, the students were reading at the 99th percentile but at the end of year, a test indicated they reading at the 95th percentile.

Percentile means position. they were first in 99th place, it actually does not cover the mark they secured.

Here the history may affect the result, means may be other students also poor in the study. Now they are in 95th place but other students may be doing better this time with these students.

So, you can not judge performance in percentile in this stage.

The answer is History.

No 12.

Assuming no misclassification of subject disease status, the disease prevalence in the case group of case-control study is always 100%. It because you are going retrospectively from disease towards cause factor.

The answer is always 100%