The Informed Consent Form (ICF) is the central document in the informed consent process of clinical trials. It provides trial participants with written and comprehensible information about all essential aspects of a clinical trial and records their voluntary, informed consent to participate. The ICF is a legally binding document and a prerequisite for the enrollment of each participant in a clinical trial. Without a validly signed ICF, no trial-related procedures may be conducted—neither screening examinations nor administration of investigational medicinal product nor collection of trial-related data.
Legal Basis, Mandatory Content, and Language
The requirements for the Informed Consent Form are anchored in several regulatory frameworks. In the European Union, Regulation (EU) No 536/2014 (Clinical Trial Regulation, CTR) governs the informed consent process for interventional clinical trials with medicinal products. Additionally, the ICH E6(R3) guideline—Good Clinical Practice—applies, providing detailed specifications on the content, language, and process of informed consent. In Germany, the German Medicinal Products Act (AMG) in Sections 40 and 41 specifies national requirements, particularly for vulnerable populations. The ICF must be signed before the initiation of any trial-related procedures and is part of the Essential Documents in the Trial Master File, where it must be archived for the entire statutory retention period.
According to ICH E6(R3) and CTR, the Informed Consent Form must contain the following information:
- Trial title, purpose, and background of the clinical trial
- Description of the investigational medicinal product, dosage, and route of administration
- Duration of participation and schedule of trial visits
- Foreseeable risks, discomforts, and potential benefits
- Description of available alternative treatments
- Data protection and confidentiality—notice of inspection rights by authorities and monitors
- Voluntary nature of participation and right to withdraw at any time without disadvantage
- Contact details of the Principal Investigator and the Ethics Committee
- Notice of insurance coverage and possible compensation arrangements
- Consent to the use of biological samples and genetic data, if applicable
The language must be comprehensible to laypersons—medical jargon is to be avoided. Readability and comprehensibility are frequently assessed using standardized readability indices. For multinational trials, country-specific adapted versions in the respective national language must be prepared; translations must be verified for content accuracy through back-translation procedures.
Preparation, Approval, and Versioning
The ICF is prepared by the sponsor in collaboration with the Principal Investigator. Before trial initiation, the document must be approved by the competent Ethics Committee—typically together with the protocol and other core trial documents. Approval must be obtained before the first participant is informed and enrolled. Any substantial amendment to the ICF—for example, following a protocol amendment—requires renewed approval and, where safety relevance dictates, re-obtaining consent from already enrolled participants (re-consent). Complete documentation of the versioning history is a central component of the Trial Master File and is routinely reviewed during regulatory inspections.
Special Populations and Emergency Situations
Enhanced requirements apply to vulnerable populations. For minors, the consent of the legal guardians must additionally be obtained; at the same time, the child must be informed in an age-appropriate manner and asked for their assent. For adults lacking capacity to consent—for example, in emergency research or in cases of cognitive impairment—specific provisions of the CTR and national legislation must be observed. In certain emergency situations, the CTR permits deferred consent when immediate enrollment is medically necessary and no legal representative can be reached in time. These exceptional provisions are narrowly defined and must be addressed in advance in the protocol and the ICF. Electronic consent procedures (eConsent) offer additional possibilities to support the process, but do not replace the personal informed consent discussion.
Relevance for clinical trials
A complete, comprehensible, and correctly signed Informed Consent Form is a fundamental requirement for compliance with Good Clinical Practice. Missing or defective consent documents are among the most common findings during regulatory inspections by BfArM, PEI, or EMA and can render trial data unusable. Verification of ICF completeness—including correct date fields and signatures—is therefore a regular component of clinical monitoring. Full-service CROs such as mediconomics support sponsors in the preparation, translation, and regulatory review of ICF templates as well as the development of child-friendly information sheets for pediatric trials.
Frequently Asked Questions (FAQ)
When must the Informed Consent Form be signed?
The ICF must be signed before the initiation of any trial-related procedures—that is, before screening, before the first blood draw, and before any other trial-related intervention. Retrospective signing is not permissible and constitutes a serious GCP violation. The date and time of signing by the participant and the investigator must be documented without gaps, as this is routinely verified during inspections.
What happens if a participant withdraws consent?
Any trial participant may withdraw consent at any time and without giving reasons, without incurring any disadvantage. The investigator must record the withdrawal in the trial documentation system. Data already collected up to the time of withdrawal may generally continue to be used—unless the participant explicitly requests destruction of all data. The precise provisions must be specified in the protocol and in the data protection section of the ICF.
How must an ICF be updated following a protocol amendment?
Any amendment that affects participant safety, trial procedures, or the burden imposed by the trial requires a revised version of the ICF. This must be approved again by the Ethics Committee. Already enrolled participants must then be informed using the updated ICF and must sign again. The investigator carefully documents this re-consent process in the case report form and in the participant’s medical record.
Regulatory References
- Regulation (EU) No 536/2014 (CTR), Articles 29–35: Requirements for informed consent in clinical trials
- ICH E6(R3) GCP Guideline, Section 4.8: Informed Consent of Trial Subjects
- German Medicinal Products Act (AMG), Sections 40–41: Special prerequisites for clinical trials
- Declaration of Helsinki (2013), Sections 25–32: Informed consent
- EU General Data Protection Regulation (GDPR), Article 9: Special categories of personal data