Assessment of Length and Readability of Informed Consent Documents for COVID-19 Vaccine Trials

Key Points Question What are the accessibility and understandability for average audiences of current informed consent documents for the COVID-19 vaccine trials? Findings This quality improvement study of 4 informed consent documents from 4 major COVID-19 vaccine trials found all to be overly long and complex, exceeding a grade 9 language complexity and requiring a mean of 35 minutes to read the entire document. It was possible to reduce the length of the documents by more than 50% and use more broadly understandable language with a grade 7 or 8 reading level. Meaning These findings suggest that informed consent documents may fail to succinctly explain the studies to participants of all reading levels and that it is possible to improve these documents to increase participant accessibility.


Introduction
Informed consent is a fundamental protection for research participants. Informed consent documents are one, albeit critical, element in a process that is meant to ensure participant understanding and voluntary participation. Federal regulations on informed consent emphasize that documents should be brief, readable, and prioritize participants' understanding. 1 Yet, over time, these documents have become longer and more complex. 1

+ Invited Commentary + Supplemental content
The COVID-19 vaccine phase III randomized clinical trials have been the most visible clinical trials in more than 30 years and collectively enrolled more than 100 000 Americans. These trials are occurring after the revision of the federal regulations that emphasize shorter, readable documents. 3 The goal of this quality improvement study was to examine how well the informed consent documents achieve the ideal of being succinct and understandable.

Methods
This quality improvement study was exempt from institutional review board review because it involved no human research participants. In this quality improvement study, we systematically evaluated the informed consent documents from the AstraZeneca, Johnson & Johnson, Moderna, and Pfizer COVID-19 phase III vaccine randomized clinical trials based on 4 criteria. First, for length, we counted words and calculated the approximate time-to-read based on a typical 240 words per minute (wpm) reading speed (range, 175-300 wpm). 4 Second, for language complexity, we used a Flesch-Kincaid Grade Level assessment. 5 Third, for readability, we evaluated the Flesch Reading Ease Score, a 1 to 100 ranking, with scores less than 60 being considered by the Department of Health and Human Services (HHS) as difficult. 6 Fourth, we assessed how the documents addressed access for placebo groups to the vaccine if it is proven safe and effective.
We wrote a shorter, more readable consent document. This document covers the same substantive material as the original informed consent forms.
All reading analysis was conducted using Readable. 7 Analysis was conducted from October 2020 to January 2021.

Results
Among the 4 informed consent documents examined, the mean (range) page count was 21.8 (17-25) pages, and the mean (range) word count was 8333 (7821-9340) words ( Table 1). At 240 wpm, a participant would need a mean (range) of 34.7 (32.6 to 35.9) minutes to read an informed consent The language complexity in all the documents exceeded a grade 9 reading level, which is higher than the recommended grade 6 reading level. 6 Additionally, all the documents had scores of less than 60 in the reading ease metric, with a mean (range) score of 52.4 (49.6-56.8), categorizing them as difficult (Table 1). 6 Finally, only 1 document indicated that participants in the placebo group might receive vaccine. Even then, the reference was oblique, and failed to specify the timeline or other details.

Discussion
This quality improvement study found that informed consent documents for the phase III Why are these vaccine trial consent documents so long and difficult to read? While it is impossible to say definitively, we posit 3 contributing factors. First, institutional review board members may not insist on shorter, more readable documents and/or may require additional material that they think, without any supporting data, will improve information transfer or promote trust. The study doctor will discuss with you the methods of birth control that you should use while you are in this research study and will help you select the method(s) that is appropriate for you. The study doctor will also check that you understand how to use the birth control method and may review this with you at each of your research study visits a Range, 0 to 100, with 100 indicating easiest to read and scores less than 60 considered difficult by the Department of Health and Human Services. It is possible to develop a measurably better informed consent document, one that is shorter, more readable, and uses less complex language. This requires work and effort at editing. Thus, it may be more useful for researchers to hire an editor to collaborate on creating better documents rather than leaving the creation of informed consent documents to researchers, legal teams, or others whose expertise is not careful, succinct writing.

Limitations
This study has some limitations. Evaluating the extent to which these informed consent documents effectively communicate to ensure participants' comprehension of each of the myriad elements of informed consent was outside the scope of this study, and this is an area that warrants additional research. It is important to concede that our rewritten form also did not achieve a grade 6 reading level. The Flesch-Kincaid Grade Level assessment depends, in part, on the syllable count of words with many syllables and the number of those words. Necessary medical terms and consent-related words without shorter substitutes can inflate the reading grade level of these documents. Thus, the appropriateness of this metric to evaluate informed consent documents merits reevaluation, perhaps with a focus on more qualitative alternatives. Such an analysis was also outside the scope of this analysis. Furthermore, we only evaluated phase III informed consent forms to allow for a more uniform comparison. While informed consent is perhaps more vital to protecting participants considering entry into earlier, riskier trial stages, the mixture of combined and stand-alone early phase COVID-19 vaccine trials compelled us to focus exclusively on documents from phase III trials.

Conclusions
The findings of this quality improvement study suggest that participant informed consent has been compromised by lengthy, complex documents. Federal guidance has not been sufficient to create shorter, more comprehensible informed consent documents. Achieving a robust informed consent process will require a renewed commitment to documents that eliminate verbose and irrelevant material. To fulfill the goal of valid informed consent, organizations involved in clinical trials should channel the judiciousness of an editor in drafting future documents.