Please show your work for ALL calculations. For each of the calculations, interpret the meaning of your results.
1.Differentiate between ecologic and Cross-sectional studies with respect to their strengths and weaknesses.
2.List 5 sources of exposure-based cohorts?
3.A researcher is trying to determine whether exposure to solvents is associated with the risk of liver cancer. From a cohort study of industrial workers, they found that three persons who worked with solvents developed liver cancer and 104 did not. Two cases of liver cancer occurred among non-exposed workers in the same type of industry. The remaining 601 non-exposed workers did not develop liver cancer. Calculate the relative risk.
4.In a population of 1,500 residents, one-half of them did not have the plague, which was transmitted by the bite of a flea. Three hundred who were bitten by a flea had the plague. Four hundred of the residents who were bitten by fleas did not develop the plague. Determine the Relative Risk of having the plague if you are bitten by a flea?
5.A researcher found out that some coal miners in a community of 960 miners had anthracosis. He would like to find out what was the contributing factor for this disease. He randomly selected 500 men (controls) in that community and gave them a questionnaire to determine if they too had anthracosis. One hundred-fifty (150) of them reported that they mined coal, but did not have anthracosis. From those who had the disease, 140 were not coal miners. Calculate the measure of association between exposure to coal dust and development of anthracosis.
