In a recent case control study on hypertension and the use of Oral Contraceptives (OC) in Queens, NY, a total of 2,700 women were diagnosed with hypertension and 1,200 did not have a history of OC. Of the 700 women without hypertension, 300 did not have a history of OC. What is the odds ratio for the association between OC use and hypertension

≈ 0.94

Explanation:

Number of women diagnosed with Hypertension = 2700

Number without history of OC  = 1200

women with history of OC = 2700 - 1200 = 1500

300 out of 700 of women without hypertension do not have history of OC

400 out of 700 of women without hypertension have history of OC

Determine the odds ratio between OC use and hypertension

Hence :

The odds ratio = ( 1500 / 1200 ) / ( 400/300 )

                         = 1.25 / 1.333 = 0.9377 ≈ 0.94