Assignment:
Answer the following questions:
A) A hypothetical case–control study was conducted to identify exposures associated with a neurologic
disorder in adolescents that is characterized by headaches and in a few severe cases seizures. Cases
(persons with the neurologic disorder) were compared to a randomly selected control group of
adolescents from the same schools the cases attended. The results of the study showed that the odds
ratio for the disease, comparing those who played video games every day to those who did not play
video games every day, was 2.1. The researchers also found that the odds ratio was 0.60, comparing
those who regularly read books, other than school textbooks, to those who did not.
Select which statements are true. Cases (students with the neurologic disorder) had greater odds of having played video games than controls. Adolescents who played video games every day had odds of having the neurologic disorder that were 2.1 times as large as the odds of those who did not play video games every day. Playing video games appeared to be a protective factor because it was associated with reduced
odds of having the neurologic disorder. Reading regularly was associated with increased odds of having the neurologic disorder by 60%. Reading regularly is not associated with the neurologic disorder because the odds ratio is under
1.0. B) The use of cellular phones has been associated with the development of brain cancer, as evidenced in several studies. However, other studies have shown no such association. The table below includes the
results of a case–control study of brain tumors and the regular use of cellular phones. This study was
conducted using a control group made up of a random sample of the population of high school students
who attended the same schools where the students with brain tumors were found. How many study subjects were cases? How many study subjects were controls? What was the ratio of controls to cases? Calculate the odds ratio that compares exposure to cellular phones among those with and
without the disease. Make a conclusion based on the calculated odds ratio C) Following are the results of a study that used a case–control design. This study evaluated factors
associated with admission to college. A total of 650 students were admitted to college (cases), and they
were compared to 650 students who were not admitted to college (controls). The purpose of this study
was to identify factors that are associated with the likelihood of being accepted into college. Which of the statements below are true regarding this case–control study. Being female was associated with increased odds of being admitted into college. Females had 40% greater odds of being admitted into college as compared to males. Alcohol consumption was not associated with being admitted into college. Those who had been admitted to college had half the odds of drinking alcohol as those who
were not admitted to college. Sedentary life was not associated with admission to college. The odds of smoking were 60% lower in students admitted to college than among those who
were not admitted to college. The odds of admission to college were 20% lower in those who used illicit drugs than among
those who did not use illicit drugs. The odds of admission to college were 2.1 times as high among students who practiced sports
regularly than among those who did not practice sports regularly. D) Consider the risk of developing breast cancer for women related to the age which they had their first
child. Calculate the odds ratio. What does this value mean?
