There are different kinds of clinical trials, including those to study:
prevention options
new treatments or new ways to use existing treatments
new screening and diagnostic techniques
options for improving the quality of life for people who have serious
medical conditions
Clinical trials are conducted according to a plan called a protocol. The
protocol describes what types of patients may enter the study, schedules of
tests and procedures, drugs, dosages, and length of study, as well as the
outcomes that will be measured. Each person participating in the study must
agree to the rules set out by the protocol.