Background
Clinical trials are conducted for the purpose of collecting data on the efficacy of medical treatments. The treatment might be, for example, a new drug, a medical device, a surgical procedure, or a preventative regime. Clinical trial protocols vary considerably depending on the nature of the treatment under investigation, but typically in a controlled trial researchers gather a group of volunteers and subject some to the test treatment, while giving the others either no treatment (known as a placebo), or an established treatment for comparison. After a defined time period, the patients in the test group are assessed for health improvements in comparison with the control group.
However, trials can vary greatly in quality. Methodological errors such as poor blinding or poor randomisation allow factors such as the placebo effect or selection bias to adversely affect the results of a trial.
Read more about this topic: Jadad Scale
Famous quotes containing the word background:
“I had many problems in my conduct of the office being contrasted with President Kennedy’s conduct in the office, with my manner of dealing with things and his manner, with my accent and his accent, with my background and his background. He was a great public hero, and anything I did that someone didn’t approve of, they would always feel that President Kennedy wouldn’t have done that.”
—Lyndon Baines Johnson (1908–1973)
“They were more than hostile. In the first place, I was a south Georgian and I was looked upon as a fiscal conservative, and the Atlanta newspapers quite erroneously, because they didn’t know anything about me or my background here in Plains, decided that I was also a racial conservative.”
—Jimmy Carter (James Earl Carter, Jr.)
“... every experience in life enriches one’s background and should teach valuable lessons.”
—Mary Barnett Gilson (1877–?)