Example: Statins For Primary Prevention
For example, the ASCOT-LLA manufacturer-sponsored study addressed the benefit of atorvastatin 10 mg (a cholesterol-lowering drug) in patients with hypertension (high blood pressure) but no previous cardiovascular disease (primary prevention). The trial ran for 3.3 years, and during this period the relative risk of a "primary event" (heart attack) was reduced by 36% (relative risk reduction, RRR). The absolute risk reduction (ARR), however, was much smaller, because the study group did not have a very high rate of cardiovascular events over the study period: 2.67% in the control group, compared to 1.65% in the treatment group. Taking atorvastatin for 3.3 years, therefore, would lead to an ARR of only 1.02% (2.67% minus 1.65%). The number needed to treat to prevent one cardiovascular event would then be 99.7 for 3.3 years.
Read more about this topic: Number Needed To Treat
Famous quotes containing the words primary and/or prevention:
“One of the effects of a safe and civilised life is an immense oversensitiveness which makes all the primary emotions somewhat disgusting. Generosity is as painful as meanness, gratitude as hateful as ingratitude.”
—George Orwell (1903–1950)
“... if this world were anything near what it should be there would be no more need of a Book Week than there would be a of a Society for the Prevention of Cruelty to Children.”
—Dorothy Parker (1893–1967)