Reference no: EM132412742

1. You know that case-controlled studies are not a strong research design when evaluating a possible cause-and-effect relationship. Which of the following would strengthen your sense that cell phones are or are not related to brain tumors?

A. A dose-response was sought.

B. Different measures of "dose" were explored.

C. Analysis was made according to which side the tumor occurred or which side the telephone was used. 

2. There may be __________ or ____________ causes, and causes may be ____________ or  _____________.

3. Given the information above, what is a possible major bias in the case-controlled study? 

4. The best evidence for cause-and-effect relationship come from a well conducted Randomized controlled trial. True/False?

5. Case-controlled studies guard against confounding and measurement biases. True/False?

6.   Cross-sectional studies are weak because they provide no direct evidence of sequence of events. True/False?         

7. In considering weight of evidence to determine cause, what four sources are available?

8. How would you grade the study in question 1?