Question

Question 28 0 out of 2 po n a case-control study of osteoporosis, 150 women were enrolled as cases and an equal number as controls. Among the cases 50 reported low calcium intake, while only 20 of the controls reported low calcium intake. Calculate the odds ratio in the association between low calcium intake and developing osteoporosis in this population.

Answer 1

	Low Calcium
	Yes	No	Total
Cases	50	100	150
Control	20	130	150
Total	70	230	300

Odds Ratio = (a/c)/(b/d) = (50/20)/(100/130) = 3.25

The odds are 3.25 times higher that a those who have low calcium will develop osteoporosis than those who do not low calcium.