Once a volunteer decides that taking part in a clinical trial could prove beneficial, there are other factors to consider that might affect participation.
Each study has its own guidelines as to who can participate, which are called eligibility criteria. To ensure the strongest results, researchers want study participants to be alike in key ways. Examples of eligibility criteria for a treatment trial might be a particular type and stage of cancer, age, gender, or previous treatments. The eligibility criteria are included in the study plan. The doctor or nurse in charge of enrolling patients for the study can provide information about eligibility criteria.
Clinical trials can take place at a university hospital or at a participant's local medical center or physician's office.
The trial may include participants at one or two highly specialized centers or it may involve hundreds of locations at the same time. Participants in the trial are under the guidance of a team including physicians and other health professionals, who would report each participant's experiences during the trial back to the center responsible for the trial's overall coordination. Experts then use the information from all of the participants to evaluate the intervention that the trial is testing.
The trial sponsor usually pays for the cost of the intervention being studied such as any drugs being compared. The sponsor also usually pays for costs associated with any special testing or extra doctor's visits that may be required.
The website of the National Cancer Institute (http://www.cancer.gov/clinicaltrials)