HLTH 503 Quiz 4

HLTH 503 Quiz 4: Experimental Studies

1. As an epidemiologist you are going to investigate the effect of a drug suspected of causing malformations in newborn infants when the drug in question is taken by pregnant women during the course of their pregnancies. As your sample you will use the next 200 single births occurring in a given hospital. For each birth a medication history will be taken from the new mother and from her doctor; in addition, you will review medical records to verify use of the drug. [N.B.: These mothers are considered to have been followed prospectively during the entire course of their pregnancies, because a complete and accurate record of drug use was maintained during pregnancy.] The resultant data are: Forty mothers have taken the suspected drug during their pregnancies. Of these mothers, 35 have delivered malformed infants. In addition, 10 other infants are born with malfunctions. The relative risk between exposure to the drug and malformations is:
2. Which of the following individuals helped draw people’s attention to the method of cohort analysis?
3. True or False? Repeated cross-sectional surveys may underestimate past smoking behavior of older age cohorts.
4. An ambispective cohort study is also known as a:
5. Forty mothers have taken the suspected drug during their pregnancies. Of these mothers, 35 have delivered malformed infants. In addition, 10 other infants are born with malfunctions.
   Suppose that a relative risk of 0.5 has been found. Which interpretation might follow?
6. True or False? Relative risk is the ratio of the risk of disease among the exposed to the risk among the unexposed.
7. Forty mothers have taken the suspected drug during their pregnancies. Of these mothers, 35 have delivered malformed infants. In addition, 10 other infants are born with malfunctions.
   The number of individuals who both did not take the drug and did not give birth to infants who were malformed was:
8. Cohort study is to risk ratio as:
9. Practical considerations in the design of cohort studies do not usually include:
10. A five-year prospective cohort study has just been completed. The study was designed to assess the association between supplemental vitamin A exposure and mortality and morbidity for measles. The RR for incidence of measles was 0.75 and the RR for measles mortality was 0.5. Which statement is correct?
11. A major advantage of cohort studies over case-control studies with respect to the role of a suspected factor in the etiology of a disease is that:
12. Nested case-control studies:
13. In contrast to observational studies, intervention studies are employed to:
14. To assess clinical end points, investigators:
15. True or False? Clinical trials enroll individual subjects and enable randomization of subjects to receive or not receive the intervention.
16. Identify which of the following six types of study designs most appropriately characterizes the situation described below. To test the efficacy of a health education program in reducing the risk of foodborne and waterborne diseases, the residents of two Peruvian villages were given an intensive health education program. At the end of two years, the incidence rates of important water-borne and food-borne diseases in these villages were compared with those in two similar control villages without any education program.
17. Identify which of the following six types of study designs most appropriately characterizes the situation described below. To test the efficacy of vitamin C in preventing colds, army recruits are randomly assigned to one of two groups: one in which 500 mg of vitamin C is administered daily, and one in which 500 mg of a placebo is administered daily. Both groups are followed to determine the number and severity of subsequent colds.
18. Which types of health issues are likely to be addressed in community trials?
19. True or False? A therapeutic trial involves the study of the effectiveness of a substance or program to prevent disease.
20. Which type of evaluation requires the collection of baseline information before the program starts?
21. A prophylactic trial is designed to:
22. A major advantage of community trials is that they are:
23. True or False? The purpose of the washout period is to reinforce the carryover effect.
24. True or False? In community intervention studies, it is important for the investigator to evaluate whether a program has achieved its intended results before assuming the benefits of the intervention.
25. True or False? Randomized controlled trials at the community level are typically used in special situations where there is a simple intervention.