One major issue in contemporary medical science is the use of humans in clinical trials of medical products. These trials occur frequently to determine the best way to manage diseases.
People are invited randomly and paid to take part in trials of an experimental drug, or new surgical procedure, in a number of countries at the one time. For example, up to a quarter of patients in some fields like breast cancer may be engaged. Other projects, one of which is to determine whether new scanning techniques can detect Alzheimer's disease, are under way. They may be given the drug or a placebo （安慰剂）, or the best existing treatment, and results compared. The trials may be "blind" with the patient not knowing which group they are in or they may be a "double-blind" with the doctors not knowing either.
Actually, so many people offer themselves willingly. Patients take the views that at least they will get special attention from the doctor if they participate and they may get access to new drugs before they become available in chemists' shops. In some countries people are paid to participate, especially in poorer countries where they may be told little of what is actually happening.
Yet there are significant risks too. One US study estimated that one in 30 people suffered side effects from such trials, and one in 10, 000 dies. Doctors say that the risk is not so great during the trial itself, where patients are closely monitored, but comes when the drug is released on the market place. For example, in 2004 a US company recalled an arthritis drug, when it was found that after 18 months of use, the risk of heart attack and stroke increased.
People who support testing claim the risks to the individual are small compared with the benefits. Even if the individual has adverse outcomes and their condition worsens, that is valuable information for the drug company. While the drug companies usually pay for the hospital trials, government has set up medical committees to handle the issue.
