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April 28, 2021

Informed Consent—We Can and Should Do Better

Author Affiliations
  • 1Wake Forest Baptist Comprehensive Cancer Center, Section on Hematology and Oncology, Department of Medicine, Wake Forest School of Medicine, Winston Salem, North Carolina
JAMA Netw Open. 2021;4(4):e2110848. doi:10.1001/jamanetworkopen.2021.10848

Informed consent is fundamental to the ethical and legal doctrines respecting research participants’ voluntary participation in clinical research, enshrined in such documents as the 1947 Nuremberg Code; reaffirmed in the 1964 Declaration of Helsinki, revised in 1975, and the 1978 Belmont Report; and codified in the United States in the 1981 Common Rule, revised in 2018 and implemented in 2019.1

Informed consent generally is understood to represent a process, with the informed consent document having a central role. The characteristics of a well-designed consent form are well known: the document must contain information, some statutorily defined, necessary to allow a participant to make an informed decision; be written at a reading level appropriate for its audience; and be of a length that enables complete and thorough reading. Yet, the content and structure of this document has been the subject of discussion for at least 3 decades, with a consistent consensus throughout this time that these documents are too difficult to read, too complex, and too long and, as a result, frequently fail to facilitate truly informed consent by study participants. While much of the blame for the failure to provide sufficiently detailed, readable, and brief consent forms has been laid at the feet of sponsors and investigators, the reality is that, while it is possible to incorporate 2 of these 3 elements into a consent form, it is all but impossible to incorporate all 3, ie, concise, sufficiently detailed yet easily readable, for anything but the simplest of clinical trials.

The study by Emmanuel and Boyle2 reviews the consent forms for the COVID-19 vaccine phase III randomized clinical trials conducted by 4 major pharmaceutical companies that resulted in US regulatory approvals for 3 of the 4 vaccines, in the context of these issues. The study by Emmanuel and Boyle2 highlights the deficiencies of the COVID-19 vaccine trial consent forms in these areas, proposes revised consent form language to improve readability, understanding, and length, and underscores how the medical community has not responded adequately to the decades-long valid criticisms concerning informed consent forms. The revisions proposed by Emmanuel and Boyle2 to the relatively straightforward COVID-19 vaccine trials’ consent forms yielded a document that was substantially longer than ideal, with an overall higher-grade reading level than optimal, underscoring the fundamental inability to successfully incorporate all 3 of the desirable qualities for a consent form into a single document.

Consent forms should be written at a level understandable to the average prospective participant. Many authorities, including the National Cancer Institute,3 relying on the 2015 Institute of Medicine report “Informed Consent and Health Literacy,” recommend an eighth-grade reading level or lower for informed consent forms, but this may be too generous a standard. The average American reads at the seventh to eighth grade level, with half of US adults unable to read a book written at the eighth grade level. The most recent study of literacy among US adults, the Survey of Adult Skills conducted through the Program for the International Assessment of Adult Competencies (PIAAC), supports this, indicating that more than half of US adults would struggle to fully comprehend current consent forms, and among self-declared individuals in fair or poor health—those most likely to participate in clinical trials with greater than minimal risk—31% have PIACC Level 1 (ie, basic sight vocabulary and can read short texts on familiar topics to locate a single piece of information) or lower literacy skills.4 Therefore, it is reasonable to conclude, as Emmanuel and Boyle2 and many others have, that a sixth grade reading level is more appropriate, noting that even this level would not address the substantial proportion of the population with literacy levels below this.5

Consent forms also should be of a length that can be easily read by the average study participant. Evidence exists that the longer a document is, the less likely people are to read it fully. In the educational context, people are unlikely to read an entire document containing more than 1000 words (ie, approximately 4 pages), and it has been proposed that consent forms should be limited to no more than 1250 words.6 Yet consent form lengths have increased steadily over the past 4 decades, with few consent forms fewer than 10 pages in length, and most substantially longer. The COVID-19 consent forms reviewed by Emmanuel and Boyle2 were a mean of more than 8000 words (range, 7821 to 9340 words), and despite their best efforts, Emmanuel and Boyle2 were only able to reduce the length to just under 3000 words.

Finally, there is the issue of the actual content of the consent form. The list of mandatory items alone runs to more than 270 words in the Revised Common Rule, highlighting the challenge of writing a consent form that is complete and understandable in fewer than 1000 or even 1250 words. Compounding this is the perception that many sponsors and institutions appear to want to use consent forms primarily as legal instruments to protect against civil litigation, undermining both the primary function of the document, as well as its accessibility, to study participants.

The study by Emmanuel and Boyle2 should be recognized as a wake-up call to sponsors, investigators, institutional review boards, and regulators to reevaluate how consent forms are drafted, reviewed, and used, along with a reappraisal of the entire consenting process. After decades of largely fruitless effort, an acknowledgment of the seemingly insurmountable challenge of drafting sufficiently detailed but easily readable and not overly lengthy documents would allow the reimagining of the entire consenting process. Considerations could include placing even greater emphasis on the discussion component of the consent process while deemphasizing the role of the consent form, a greater use of multimedia and other technology, more formal scripting of consenting discussions, mandatory documentation of confirmation of adequate comprehension by study participants, and even regulatory reform, among other improvements. Such an appraisal and revision to the process would be neither simple nor without cost, but if history is any guide, failure to act is likely to lead to having the exact same conversation a decade from now.

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Article Information

Published: April 28, 2021. doi:10.1001/jamanetworkopen.2021.10848

Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2021 Grant SC. JAMA Network Open.

Corresponding Author: Stefan C. Grant, MD, JD, MBA, Wake Forest Baptist Comprehensive Cancer Center, Section on Hematology and Oncology, Department of Medicine, Wake Forest School of Medicine, Medical Center Blvd, Winston Salem, NC 27157 (

Conflict of Interest Disclosures: Dr Grant reported having equity in and serving as General Counsel of TheraBionic.

Office for Human Research Protections. 2018 Requirements (2018 Common Rule). Accessed February 21, 2021.
Emmanuel  EJ, Boyle  CW.  Assessment of length and readability of informed consent documents for COVID-19 vaccine trials.   JAMA Netw Open. 2021;4(4):e2110843. doi:10.1001/jamanetworkopen.2021.10843Google Scholar
National Cancer Institute. NCI informed consent template. Accessed February 21, 2021.
National Coalition for Literacy. Literacy and numeracy skills of U.S. adults. Accessed February 21, 2021.
Rea  A. How Serious is America’s Literacy Problem? Library Journal. April 29, 2020. Accessed February 21, 2021.
Sharp  SM.  Consent documents for oncology trials: does anybody read these things?   Am J Clin Oncol. 2004;27(6):570-575. doi:10.1097/01.coc.0000135925.83221.b3PubMedGoogle ScholarCrossref
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    2 Comments for this article
    But Would It Pass the IRB?
    Justin Starren, MD, PhD | Northwestern University
    The paper provides an example of how informed consent documents are often long, complex and difficult to read. However, the work leaves out significant details.

    First, who determined that the content was equivalent, the rewriter or an independent reviewer? We all believe that our own writing is clear and parsimonious.

    Second, was the revised text reviewed by any IRB to see if it would pass their approval? My experience is that the most complex language is often the boilerplate required by various IRBs.

    Third, how does this compare to other commonly used
    consent documents? How does it compare to other vaccine trials?

    Without that information, it is impossible to know what we should actually do to improve our consent documents.
    Informed Consent - The Nemesis of IRBs and Patients!
    Richard Reiling, M.D. | The Boonschaft School of Medicine at Wright State University
    Having lived through the era of Institutional Review Boards (IRB) from the early eighties, informed consent has consistently generated the most time and effort of such boards, especially when lay people are involved. The obvious concern about the need of patients and families to know what they should expect from the intended clinical trial must and have been the primary concern in dealing with informed consent. However, the supposed need to be all-inclusive has expanded the process, as Emanuel and Boyle's article indicate. Even at best the informed consent is too long.

    The heart of the issue
    resides in the concern about lawsuits and not necessarily about the patient's best interest. In the early years and to some extent today, the only part of the IRB process understood by lay members and even clinical members is informed consent. At times, the worst research can pass the IRB as long as the informed consent has been worked over with constant text re-adjustments.

    There are many pediatric protocols with informed consent documents greater than 20 pages and presented to a very concerned parent(s) who really cannot easily comprehend the protocol as well as the cancer in the first place - a real burden, indeed. In many cancer protocols there are multiple drugs used and every conceivable side effect is listed along with the relative frequency of occurrence, which often consumes several pages themselves. There are obvious repeats of the same side effects with different drugs and no correlation with the other drugs,  leaving the patient with no basis on which to attribute the side effect(s) in the first place.

    I have spent considerable time on hospital-based IRBs, one of which I initiated in the early eighties, and eventually on IRBs of larger academic institutions. Most recently I have participated on a national IRB (Advarra).  Only in the latter was there really the expertise to tease out the protocol as well as the informed consent; but frivolous word and concept adjustments still occurred. Even in the best IRB process, informed consent documents, especially in oncology, are extensive and rarely read by the intended participant.

    In my own practice, it is necessary to have a nurse or trained associate review the informed consent as well as the protocol itself with the patient and family. This is very time consuming. Even more concerning is the need to proceed with the patient's care and if there is any hesitation as to the patient's understanding the protocol offer is withdrawn and the patient started on approved therapy. In the long run this is not good and tends to select out the more educated and economically advantaged populations for study participation.

    There is a definite need to develop a task force of all specialities, and all stake holders (to include the government, Pharma, and the legal profession), to make the process more expeditious and patient-friendly.