A recent prospective cohort study analyzed the effect of calcium plus vitamin D supplement use on the development of osteoporosis (weak and brittle bones).
What are the null and alternative hypotheses being investigated in this study? (Be sure to specify the exposure-outcome association under study along with the measure of association you will use.)
The authors reported a p-value for the association of 0.02. Which of the following statements are implied by this p-value?
a. Using calcium plus vitamin D supplements is associated with a lower risk of osteoporosis compared to not using supplements.
b. There is a statistically significant association between the use of calcium plus vitamin D supplements and osteoporosis at the 0.05 alpha level.
c. The 95% confidence interval for the relative risk contains the value of 1.
d. Under the alternative hypothesis, the probability of obtaining a result as extreme or more extreme that the one observed is 2%.
e. All of the above
A sample of Cambridge school-aged children are interviewed about the number of pieces of candy they received while trick-or-treating. For the 64 children surveyed, the mean number of pieces of candy collected was 37, with a standard deviation of 10. Calculate the 95% confidence interval for the sample mean number of pieces of candy collected.
State the formal statistical interpretation of the 95% confidence interval calculated in the previous question.
The solution uses hypothesis testing for prospective cohort study.