In randomized trials patients with same risk factors will receive different treatments. The selection of the treatment for a patient is done randomly. At the time of randomisation it is unclear which of the randomized treatment arms will be the best one in respect to outcome or side effects in this group of patients. One group of patients will receive the standard treatment, while the others are treated differently. This allows to find better treatments, that can be applied to all patients in future. In these trials stopping rules are defined to reduce unnecessary risks to patients. All of these trials have to pass an ethical committee which will judge the safety of the randomized question for patients enrolled in a randomized trial. Usually patients enrolled in a clinical trial are better observed than non-enrolled patients. In addition participating in a trial gives patients the opportunity to receive new and otherwise not available drugs. Randomised patients can be the first to benefit from such new drugs.
