Review Questions for Chapter 8 

  1. This term refers to the explanatory variable in an epidemiological study.
  2. This term refers to the response or outcome variable.
  3. [T/F?] "Measure of association" and "measure of effect" are often used  interchangeably in epidemiology.
  4. What does it mean when we say there is a positive association between an exposure and disease? What does it mean when we say there is a negative association?
  5. [T/F?] Associations equals causation.
  6. [T/F?] Absolute comparisons are made by division.
  7. [T/F?] Relative comparisons are made by division. 
  8. When I say, "there will be 5 additional cases per 1000 exposures," am I referring to an RR, RD, AFe, or AFp?
  9. When I say, "the exposure doubles risk," am I referring to an RR, RD, AFe, or AFp?
  10. This epidemiologic measure quantifies the effect of the exposure in absolute terms. 
  11. This epidemiologic measure quantifies the effect of an exposure in relative terms. 
  12. An exposed group has a risk of 50% and a non-exposed group has a risk of 35%. Calculate and interpret the RD associated with this exposure.
  13. Same data as prior question: calculate and interpret the RR? 
  14. A report states "people who do not wear seat belts are eight times as likely to die in an automobile accident." Is this statistic an incidence attributable fraction, relative risk, or risk difference?
  15. The one-year risk in an exposed group is 15 per 1000. The one-year risk of disease in a non-exposed is 10 per 1000. Would it be correct say that the exposure increases risk by 150%? Explain your reasoning.
  16. An RR of 1.4 suggests risk increases in relative terms by ______% with exposure. 
  17. [T/F] A RR of 0.7 indicates a positive association between the exposure and disease. 
  18. [T/F] A RD of 0.7 per 100 indicates a positive association between the exposure and disease.
  19. What is the baseline RD, i.e., the RD that indicates no additional risk with exposure, or “no association” between the exposure and disease?
  20. What happens to the RD when we redefine the exposed group as non-exposed, and and vice versa?
  21. What does a rate difference of �54.3 per 10,000 person-years mean in plain terms?
  22. What is the "baseline" relative risk, i.e., the relative risk that indicates no additional risk associated with exposure? 
  23. What happens to the numeric value of the RR if we switch designation of the exposed group as non-exposed, and vice versa?
  24. A risk ratio is 1.85. How much does the exposure increase risk in relative terms? 
  25. This statistic quantifies the proportion of cases that would be averted had the exposure been absent in exposed cases.
  26. This statistic quantifies the proportion of cases that would be averted if the exposure had been absent in the population. 
  27. How can the sum of attributable fractions associated with multiple exposures exceed 100%?
  28. Explain how AFp and AFe differ. 
  29. Matching these terms with their brief description. 
    Terms: RR, RD, AF 
    Descriptions    : (a) quantifies effect of the exposure in absolute terms  (b) quantifies effect of the exposure in relative terms  (c) quantifies proportion of cases that would be averted with removal of the exposure from a group

Key Last edit: 06/07/2009