Short answers, pulled from the story.
A randomized controlled trial is a type of scientific experiment designed to evaluate the efficacy or safety of an intervention by minimizing bias through the random allocation of participants to one or more comparison groups. In this design, at least one group receives the intervention under study such as a drug, surgical procedure, medical device, diet, or diagnostic test.
The first reported clinical trial was conducted by James Lind in 1747 to identify a treatment for scurvy. Principles for conducting controlled trials were further elaborated by the Irish physician James Henry in 1843.
Austin Bradford Hill is credited as having conceived the modern RCT during the 1948 paper entitled Streptomycin treatment of pulmonary tuberculosis which described a Medical Research Council investigation. This publication marked the first published Randomized Controlled Trial in medicine.
One study found 28 Phase III RCTs funded by the National Institute of Neurological Disorders and Stroke prior to 2000 with a total cost of US$335 million for a mean cost of US$12 million per RCT. The same study projected that these 28 RCTs produced a net benefit to society at 10-years of 46 times the cost of the trials program.