Clinical Scenario A 55-year-old woman presents with new-onset hypertension. L ifetime risk of coronary heart disease and stroke is directly rel ated to higher blood pressure; therefore, the primary reason for treating hypertension is to reduce morbidity and mortality fro m these conditions. Convincing evidence for vigorous early treatment of hypertens ion began to appear in 1967 with publication of the landmark Veterans Administration Cooperative Study, the first large-scal e, placebo-controlled, randomized, prospective study, which fo llowed patients with moderate to severe hypertension and foun d that rates of major nonfatal events and cardiovascular death f ell with treatment more than 10-fold among those with severe hypertension and 3-fold among those with moderate pressure e levations.
Treatment was more effective in reducing risks of stroke and c ongestive heart failure. With the extensive literature now avail able, there is no longer any doubt that the benefit of lowering blood pressure is real, reducing all of the major complication o f hypertension significantly. Generic beta blockers are inexpensive and may seem appealin g as initial antihypertensive therapy. However, the effectivenes s of beta blockers to reduce cardiovascular morbidity and mort ality must be evaluated. Clinical Question Should beta blockers be used as first-line treatments for loweri ng blood pressure?
Ways to determine the value of a therapy There are plenty of other ways to decide about the value of a tr eatment: (1) to ask the clinical experts; (2) to conduct a systematic review of all relevant studies; (3) to carry out an observational studies, such as cohort - anal ytic studies of treated and untreated patients or case-control st udies of patients who do and don’t have certain outcomes?
Introduction to randomized controlled trials More than 2000 years ago, Hippocrates noted that judging the benefits of a treatment should be based on the treatment’s effe cts on patients. In modern medicine, the number of randomized controlled tria ls, accepted as “gold standard” by which the usefulness of a tre atment is determined, reported has grown exponentially. The Cochrane Library lists 635,167 clinical trials in “Cochran e Central Register of Controlled Trials” till Dem 20, 2010. They have become the underlying basis for what is currently c alled evidence-based medicine.
What is a randomized controlled trial? The randomized controlled trial (RCT) is a study in which peo ple are allocated ‘at random’ to receive one of several interven tions. The interventions are sometimes called ‘clinical maneuvers’, a nd include varied actions such as preventive strategies, diagno stic tests, screening programs, and treatments. For instance, if we are conducting a study in which patients with primary hype rtension are randomized to receive either beta blockers or anot her drug for the prevention of stroke, the interventions would be beta blockers.
- Spring '16
- Clinical trial, Randomized controlled trial, RCT