In the city of Epiland, public health agencies realized that the prevalence of cancer x, a very aggressive type of cancer, has been rising for the last 15 years. Some epidemiologic studies were conducted to find the causes of this type of cancer to be able to implement preventive strategies to reduce the mortality of this disease. One study conducted by researchers from the University of Epiland found that the attributable proportion of disease among smokers is 33.3% and the attributable proportion of disease among people that drink water with a high concentration of heavy metals is 75.4%.
Required:
a. Assuming that the population size is 1,000 people, the prevalence of smoking in Epiland is 60% and the percentage of people drinking water with a high concentration of heavy metals is 30%, calculate the total number of cases of cancer x that could be prevented if each one of the exposures were eliminated. What would be your suggestion to the public health agencies if they asked you which one of the exposures would have a greater impact on reducing the prevalence of the disease if it was eliminated?
b. Would your suggestion be different if the percentage of people drinking water with heavy metals were 10% and the prevalence of smoking remain the same? Which measure of association would be more efficient in helping you answer these questions?