The principles of informed consent in the current revisions of the Declaration of Helsinki (Appendix 1) and the International Ethical Guidelines for Biomedical Research Involving Human Subjects (2) should be implemented in each clinical trial.
(a) Information should be given in a language and at a level of complexity understandable to the subject in both oral and written form whenever possible. No subject should be obliged to participate in the trial. Subjects, their relatives, guardians or, if necessary, legal representatives must be given ample opportunity to enquire about details of the trial. The information must make clear that the trial is a research procedure, that participation is voluntary and that refusal to participate or withdraw from the trial at any stage will not prejudice the subject’s care, rights and welfare. Subjects must be allowed sufficient time, determined by their health condition and/or the illness, to enquire about details of the trial and to decide whether or not they wish to participate.
(b) The subject must be made aware and consent that personal information may be scrutinized during monitoring, auditing or inspection of the trial by properly authorized persons, the sponsor or relevant authorities, and that participation and personal information in the trial will be treated as confidential and will not be publicly available. This principle may be modified by national laws and regulations.
(c) The subject must have access to information about insurance, if any, and other procedures for compensation and treatment should he or she be injured or disabled by participating in the trial.
(d) If a subject consents to participate after a full and comprehensive explanation of the study, this consent should be appropriately recorded. The explanation should include the aim of the study; the expected benefits for the subjects and/or others; the possibility of allocation to a reference treatment or placebo; the risks and inconveniences - e.g. invasive procedures; and, where appropriate, an explanation of alternative, recognized medical therapy. Consent must be documented either by the subject’s dated signature or in agreement with local laws and regulations by the signature of an independent witness who records the subject’s consent. In either case, the subject must be informed that signature confirms that the consent is based on information which has been given, and that the subject has freely chosen to participate without prejudice to legal and ethical rights, while reserving the right to withdraw from the study at his or her own initiative at any time, without having to give any reason. If, however, the reason for withdrawal relates to an adverse event(s), the investigator should be informed.
(e) Careful consideration should be given to ensuring the freedom of consent obtained from members of a group with a hierarchical structure - such as medical, pharmacy and nursing students, hospital and laboratory personnel, employees of the pharmaceutical industry, and members of the armed forces. In such cases the willingness to volunteer may be unduly influenced by the expectation, whether justified or not, of benefits associated with participation or of a retaliatory response from senior members of the hierarchy in case of refusal to participate. Other vulnerable groups whose consent also needs special consideration include patients with incurable diseases, people in nursing homes, prisoners or detainees, the unemployed or people on a very low income, patients in emergency departments, some ethnic and racial minority groups, the homeless, nomads and refugees. If such categories are part of the population to be enrolled in a clinical trial, the ethics committee should consider carefully the appropriateness of the informed-consent process.
(f) If the subject is incapable of giving personal consent (e.g. in the case of children or adults who are unconscious or suffering from severe mental illness or disability), the inclusion of such patients in a trial may be acceptable provided: it is permitted by local laws and regulations; the ethics committee is, in principle, in agreement; and the investigator thinks that participation will promote the welfare and be in the interest of the subject. The agreement of a legally acceptable representative that participation will promote the welfare and be in the interest of the subject should also be recorded by a dated signature. If the patient is incapable of giving either signed informed consent or witnessed signed verbal consent, this fact must be documented by the investigator, stating the reasons.
(g) In a non-therapeutic study, i.e. when there is no direct clinical benefit to the subject, consent must always be given by the subject and documented by his or her signature.
(h) The trial subjects should be informed that they have access to appropriate (identified) persons to obtain further information and medical advice or escape treatment, if necessary.
(i) Any information that becomes available during the trial which may be of relevance to the trial subjects must be made known to them by the investigator.
(j) The subjects should be informed of the circumstances under which the investigator or the sponsor might terminate their participation in the study.