Table 2 Informed consent models
From: Ethical aspects of sudden cardiac arrest research using observational data: a narrative review
| Â | Model | Description | Advantages | Disadvantages |
|---|---|---|---|---|
Level of control | Opt-in | Actively given, explicit consent | - Promotes autonomy - Respects patients’ expectations and preserves trust | - Lower response rates and potential consent bias - Relatively costly and time-consuming |
Opt-out | Consent is presumed unless participant objects | - Higher participation rates and less bias than opt-in - More practical, less costly | - Assumes that people want to participate: may infringe upon autonomy - Potentially less informed | |
No consent | Study is conducted without consent (exception/waiver) | - Maximum participation rates and no consent bias - Most practical, least costly | - No control whatsoever by data subjects: least autonomy-enhancing | |
Timing | Prospective | Consent is given prior to the start of data collection | - Promotes autonomy - Respects patients’ or representatives’ expectations and preserves trust | - Time pressure and stress in emergencies: consent not fully informed/valid - Excluding (temporarily) incapacitated subjects causes bias and may not respect subjects’ wishes |
Deferred | Retrospective consent which is sought after data collection | - Provides temporarily incapacitated subjects the opportunity to participate - More valid than prior (subject or representative) consent in stressful situations | - Logistical issues with reaching participants - Data are already collected: less autonomy-enhancing than prior consent | |
Specificity | Study-specific | Consent for the use of data for one specific aim | - Promotes autonomy since patient has a high level of control over uses | - Requires re-contacting subjects for new aims: logistical challenge and burden for participants - Bias when contact attempts are unsuccessful |
Tiered | Subject chooses from a list what types of research are allowed (online: dynamic consent) | - Promotes autonomy since patient has a high level of control over uses | - Burdensome and complicated for subjects: requires detailed understanding | |
Broad or blanket | Consent for overall research topic (broad) or without limitation (blanket) | - Smallest burden for researchers and patients in terms of re-contacting | - Broad consent may not be truly informed - Blanket consent often not accepted by research ethics committees |