Q1. What was the primary research question being investigated by this study? (2 marks) Q2. This study is an example of a case-control study. Do you think another study design would have been more appropriate? Explain your answer. (3 marks)
Q3. What was the ‘case definition’ used in this study and how have the authors reduced information bias here? (4 marks)
Q4. Explain how the controls were selected. (4 marks)
Q5. Identify and explain one strength and one limitation of the method for exposure assessment? (4 marks)
Q6. In your own words, provide an interpretation of the result of 1.40 (0.61–3.22) in Table 3. (3 marks)
Q7. Suppose you discover that Sokal et al. had incorrectly classified the exposure status so that 10% of both the cases and controls were incorrectly classified as not exposed, when in fact they were exposed. The data before the correction are shown below. Before: Case Control Total Exposed to quinacrine 9 18 27 Not exposed to quinacrine 597 1756 2353 Totals 606 1774 2380