Writing a consent form at the reading level participants need
A consent form is written to a reading level set as a school grade, so that participants can follow it. Targets set that level, readability measures check a draft against it, and plain, conversational rewriting of research language brings the form to it.
The required reading level
The readability of a consent form is vital to protecting the rights and safety of trial participants. 21 CFR 50.20 and section 4.8.6 of the International Conference on Harmonisation (ICH) guideline for good clinical practice require study information to be understandable to participants. It is critical that a consent form be written at the appropriate level.
The average US adult reads at an eighth- or ninth-grade level, but the US Department of Health and Human Services recommends that any plain-language material be written at a fifth- to sixth-grade level. Sponsors of clinical trials commonly want consent forms written at a sixth- to eighth-grade level. Several ethics committees, including that of the MD Anderson Cancer Center, require consent documents to be written at a sixth- to eighth-grade level.
A consent form for an adult participant should contain every federally mandated requirement and also be written at a sixth- to eighth-grade level, a language level suitable for WebMD but not for JAMA. The reason is that participants who meet every inclusion criterion are still distinct individuals, and even those who share a condition do not all have the same mental or physical capacity to make an informed decision. Meeting both demands is challenging for a complex biomedical protocol, where reaching that level of understanding among the study population may take more words and, ultimately, a longer form. The reading-level requirement applies to every document a participant sees, including instructions for use, surveys and advertisements.
Measuring readability
A word-processing program such as Microsoft Word is helpful in meeting the reading level, because it provides a readability score after it finishes checking spelling and grammar. Readability tools such as the Suitability Assessment of Materials instrument and the Participant Education Materials Assessment Tool can also be incorporated into the quality control process of the form.
For writers who need further guidance, training materials are available online. The Program for Readability in Science and Medicine (PRISM) has developed a comprehensive toolkit for implementing standard language and document structure, and the National Institutes of Health (NIH) and the Centers for Medicare & Medicaid Services (CMS) have developed health literacy toolkits focusing on clarity, format, organisation and tone. For content aimed at lay readers, at about the eighth-grade level required for consent forms, guidance from PRISM, the NIH or CMS, with a first-pass check by the Flesch Reading Ease test, may be most appropriate. Developing a validated readability statistics tool is warranted.
Plain, conversational language
Studies show that consent forms written in simplified plain language decrease anxiety and increase satisfaction with the consent process. A conversational style can help convey the information clearly and reassure participants, or the parents of participants who are children, that the research is being conducted ethically.
Writers face the challenge of integrating the guidelines of ICH E6(R2) and of the relevant regulatory agencies into the form while keeping to the plain-language objective. Including the required elements ensures that the form meets regulatory requirements, but it does not give the form a plain-language focus. Writers who know their intended audience can weave the elements in with words the audience can identify with. How the form is structured, how it flows, a conversational tone and one key message per paragraph help the reader process the information more easily. Key messages that are concise and correctly conveyed give readers a better grasp of the form. Medical writers are on the front lines of helping translate the essential information a consent form requires into plain language for participants, and being able to creatively interlace essential regulatory information with plain language is a growing competence required of them.
Rewriting research language
Medical jargon and research terminology lead to confusion, misunderstanding, anxiety and misconceptions about the purpose of a trial and of treatment. Writers should either explain medical and scientific terms or substitute commonly understood ones. The following sample language choices for a consent form set wording to avoid beside wording to use.
| Not | But |
|---|---|
| "You will be randomized into one of the study groups described below." | "You will be 'randomized' into one of the study groups described below. Randomization means that you are put into a group by chance. A computer program will place you in one of [#] study groups. Neither you nor your doctor can choose the group you will be in. You will have an [equal/one in three/etc.] chance of being placed in any group." |
| "Study data will be published in the medical literature." | "If new information about the study device/drug becomes available during the study, the investigator or staff will tell you about the new information and will discuss with you whether you want to continue in the study. Remember that participation in this study is entirely voluntary and you are free to stop participating in the study at any time without giving a reason." |
In one edit of a consent document, the original paragraph described a drug as an inhibitor of the epidermal growth factor receptor (EGFR) that followed the first drug of its type. It said the drug specifically targets the EGFR tyrosine kinase, which is highly expressed and occasionally mutated in various forms of cancer, and binds reversibly to the receptor's adenosine triphosphate (ATP) binding site. It then explained that, for the signal to be transmitted, two members of the EGFR family form a homodimer and use a molecule of ATP to autophosphorylate each other, which changes their intracellular structure and exposes a further binding site for proteins that cause a signal cascade to the nucleus, and that inhibiting the ATP makes autophosphorylation impossible and stops the signal. The edit replaced all of this with two sentences: "Drug X is designed to block the activity of a protein found on the surface of many tumor cells that may control tumor growth and survival. This may stop tumors from growing."