Hypertension is the most important modifiable risk factor for coronary heart disease (the leading cause of death in North America), stroke (the third leading cause), congestive heart failure, end-stage renal disease, and peripheral vascular disease.
The results of a survey or a cross-sectional study can also be used to estimate the relative risk. Kuzma uses the data from a community health survey of retirees to study the relationship between smoking and heart disease. The data are given in the table. Does the retiree have heart disease? (Is the disease present?) YES NO Total
Then, say research shows that a new treatment reduces the relative risk of getting this disease by 50%. The 50% is the relative risk reduction, and is referring to the effect on the 2. 50% of 2 is 1. So this means that the absolute risk is reduced from from 2 in 20, to 1 in 20.