Informing a patient that he has cancer, and then giving him a research consent form to sign is probably not appropriate. Having a patient sign hospital admissions and clinical consent forms along with research consent forms is also not appropriate. Depending on the complexity of the material and the abilities of the subjects, it might be necessary to ask questions of the subject in order to be sure that the information is understood. The rule of thumb is to give people enough information to allow them to make an informed decision, and that this be done in a way that would allow them to say no if they wanted to. Other elements that often should be included are an estimation of the number of subjects participating in the research, how the subjects were selected, and, when appropriate, subjects should be told who is funding the research.
Children can give assent.
There are a very few circumstances in which minors can give legal consent. However, under most circumstances the parent or legal guardian of a minor must provide written permission before a child is allowed to take part in a research. That means that they voluntarily agree to be in the research. Generally, verbal assent through the use of a script should be obtained from children 7 to 11 years of age. Written assent using a written document for the children to sign is sought for older children.