Читать книгу Randomised Clinical Trials - David Machin - Страница 128

Before any trial can take place, individual subjects have to be identified, and formal processes for their consent will have to be instituted. The precise details will depend on the type of trial contemplated, for example, whether it involves an invasive procedure, concerns primary intervention, or has therapeutic intent. Also, if it involves participants such as children, the very elderly, healthy volunteers, the terminally sick or women of fertile age then this may raise particular issues, for example, requiring proxy consent, or reassurance that the trial drugs will not compromise subsequent fertility.

Importantly the patient (or the consent giver) should understand that no‐one knows in advance which therapy will be allocated, and that they should be willing to accept whatever the allocation may be. If they are unwilling, they should not be recruited to the trial.

The ideal is that each patient or volunteer gives fully informed and written consent. However, departures from this will be appropriate in specific circumstances. For example, such departures may concern patients that are unconscious at admission to hospital, patients with hand burns that are so severe that they affect their ability to provide their signature, very young children or those mentally compromised. In these cases, a proxy may consent for them or in the case of those with severe burns witnessed verbal consent may be substituted.