Question

A recent study examined the association between high blood pressure and increased risk of death from cardiovascular disease. There were 2676 men with low blood pressure and 3338 men with high blood pressure. In the low-blood-pressure group, 21 men died from cardiovascular disease; in the high-blood-pressure group, 55 died. a. Compute the 95% confidence interval for the difference in proportions. b. Do the study data confirm that death rates are higher among men with high blood pressure? State hypotheses, carry out a significance test, and give your conclusions.

Answer 1

Find the odds of a man with high blood pressure dying from cardiovascular disease. 55 p .0165 3338 = p .0165 .0165 .0168 1 p 1 .0165 .9835

Do the same for a man with low blood pressure. 21 p .0079 2676 = = p .0079 .0079 .00796 1 p 1 .0079 .9921 = = = − − ----->

Calculate the odds ratio with the odds for the high blood pressure group in the numerator. Describe the result in words. HBP LBP odds .0168 odds ratio 2.11 odds .00796 = = = Men with high blood pressure are 2.11 times more likely to die from cardiovascular disease.