Hviid A, Stellfeld, Wohlfart, Mallbye M. Association between thimerosal-containing vaccine and autism. JAMA 2003;290:1763-1766.
Please respond to the following questions about the assigned paper. Please submit your answers by midnight on Sunday and bring your completed submission to class on Monday for discussion. Please comment on whether you find the conclusions of the researchers valid. Why or why not?
Questions
1. What exactly is the hypothesis (or hypotheses) being tested in this study?
2. What are the arguments for and against the biological plausibility of an association between thimerosal and autism?
3. What would be the design of a randomized clinical trial to test the hypothesis and do you believe it can it be carried out? Why or why not?
4. What are the advantages of constructing a cohort by record linkage?
5. Could this study be done in the US?
6. From the table, which numbers tell you that there is no association between thimerosal and autism?
7. From the table, explain in a sentence what this means: “Trend (increase in RR per 25 g eHg) 0.98 (0.90-1.06)”
8. From the table, calculate the incidence rate of autism for children who received thimerosal and for children who did not. What is the unadjusted relative risk of autism for children who received thimerosal? Write a sentence describing what that RR means. Compare that to the relative risk in the table: Is there evidence of confounding by age and
