Elsevier

The Lancet Oncology

Volume 9, Issue 5, May 2008, Pages 485-493
The Lancet Oncology

Health-care Development
Improvement of informed consent and the quality of consent documents

https://doi.org/10.1016/S1470-2045(08)70128-1Get rights and content

Summary

Guidelines on informed consent intend to protect patients and promote ethical research conduct. To give informed consent, individuals should understand the purpose, process, risks, benefits, and alternatives to research (or a proposed clinical intervention) and make a free, voluntary decision about whether to participate. Many participants have incomplete understanding of various features of clinical trials. Issues associated with the length, format, and language of documents for written informed consent are common. Here, we analyse the written consent form, particularly in the context of clinical research, and the discussions that take place between clinician or investigator and patient. We review strategies to improve consent forms, particularly the use of plain language. Recommendations are made on discussions between investigator and patient to improve participant comprehension and satisfaction with the informed-consent process.

Introduction

Guidelines on informed consent intend to protect patients and promote ethical research conduct through full explanation of a proposed treatment, including any possible harms, and through the requirement that people freely consent (figure).

In the research setting, the idea of written informed consent dates from at least 1900, when Walter Reed obtained written consent from patients in his research on yellow fever in Cuba.1 The practice of obtaining informed consent in clinical settings has been done for centuries, founded partly on perceived obligations derived from the Hippocratic oath. To some extent, the practice of informed consent in clinical care and in the research setting have evolved separately, leading to increased regulation in the research setting.

An important event in the codification of informed consent occurred in the USA in 1914 when Justice Cardozo laid down the basic principle that has shaped US law on informed consent and affected developments elsewhere. The principle is that: “every human being of adult years and sound mind has a right to determine what should be done with his own body”.2

The Nuremberg Code was developed in 1947 after human experimentation by Nazi doctors and the trial of those responsible. This Code established a set of principles and guidelines for the ethical conduct of clinical research and was a foundation for future guidelines.

In the clinical setting, the term “informed consent” arose in the USA in 1957. It shifted emphasis from medical paternalism towards that of a duty to respect patient autonomy. Californian law created an “informed-consent standard”, stating that the nature, consequences, harms, benefits, risks, and alternatives of a treatment was the information needed by an ordinary person to make a “reasonable” decision about its acceptance or rejection.3

The World Medical Association Declaration of Helsinki in 19644 established worldwide ethical principles for medical research that involved human participants:

“…each potential subject must be adequately informed of the aims, methods…anticipated benefits and potential risks of the study and the discomfort it may entail. The subject should be informed of the right to abstain from participation in the study or to withdraw consent to participate at any time without reprisal. After ensuring that the subject has understood the information, the physician should then obtain the subject's freely given informed consent, preferably in writing”.

Ethics guidelines for scientific research that involves human beings have been founded on these important principles.5 An “informed-consent doctrine” gradually evolved that was consistent with these guidelines and legal precedents.6 A US court case of Cobbs vs Grant7 noted that the doctrine of informed consent is “anchored” in four postulates: first, patients are generally ignorant of medicine; second, patients have a right to control their body and decide about medical treatment; third, consent to treatment must be informed to be effective; and fourth, patients depend on their physicians for truthful information and must trust them. These postulates refer to clinical treatment, but also apply in the research setting.

Section snippets

Main principles of informed consent

Informed consent has two main aims: first, to respect and promote participants' autonomy; and second, to protect them from potential harm. Provision of information in an understandable way lends support to both these aims. Furthermore, guidelines promote ethical conduct of research by establishing a standard and by reflecting community expectations. Patients need to understand the diagnosis, prognosis, nature and purpose of the intervention, alternatives, risks, and benefits—these are minimum

Clinical care and clinical research: similarities and differences

Respect for patient autonomy and protection from harm are paramount in clinical care and research settings. Patients need information to make informed decisions. Reasons for a potential intervention and the potential negative effects should be explained to the patient in an understandable way.

However, clinical care and clinical research differ. The main aim of clinical care is to benefit a patient. By contrast, the main aim of research is to gain new knowledge; benefits from such research are

Emphasis on disclosure

Current practice in obtaining informed consent seems to have been shaped by emphasis on the legal duty of disclosure, particularly in the research setting. Consent is seen as an action, concluded by signing a form. However, informed consent needs not only disclosure and a signature, but also promotion of participants' understanding of the research project and the voluntary nature of their decision to participate.12

The written informed-consent document (ie, consent form) is an important part of

The written consent form: readability and comprehension

Written consent is needed for almost all studies. For more than 25 years, researchers have noted that consent forms might be written inappropriately.15, 39, 40

In the US Department of Health and Human Services, consent forms are required to be “in language understandable to the subject or representative”.40 The ICH guideline recommends use of oral and written language that is “as non-technical as practical and…understandable to the subject”. The US National Institutes of Health recommend writing

Plain language

Plain language (commonly called plain English) is straightforward and easy to understand. Advocates have called for its use in government, legal, and medical documents since the 1970s, when plain-English movements arose in the UK and the USA, and then worldwide (panel 1).

In non-clinical-trial settings, information written in plain language assists in decision making about medical treatments,47 strengthens intentions to implement clinical guidelines, increases positive feelings towards the

Modification of consent forms

Various studies have looked at improving the readability of the consent form. Some have concluded that understanding might be improved if the consent form is easy to read.50, 51, 52, 53, 54 Others suggest that understanding and recall might be improved if care is taken in reading the consent form16, 23 and if sufficient time is allowed to read them.21, 55 Short consent forms might also be useful.13, 15, 51 Enhanced and simplified print versions might benefit people with poor reading skills.56

The discussion

Alongside written information comes the discussion between a prospective trial participant and the investigator, trial coordinator, research nurse, or research assistant.

Although the patient's signature might represent agreement, it does not imply understanding. It might be evidence of consent, but not proof. Given the duty of disclosure and the patient's individual circumstances, researchers should record details of risks explained, queries and concerns raised by patients, and responses to

Decision aids and prompts

A decision aid might improve satisfaction and understanding, at least for some studies and some patients. A decision aid for women who were considering participation in prevention studies for breast cancer seems to have been received favourably.60 After reading the decision aid, women seemed to have good subjective understanding of the clinical trial.

Currently under investigation in a randomised controlled trial is the use of a question prompt sheet about clinical trials. These sheets increase

Training of investigators

In 1997, Skene and Millwood,62 showed poor understanding by doctors of the law's requirements for disclosure, which might be improved with increased education.62 The researchers suggest that medical journals are an important way that doctors gain new knowledge. Gore63 highlighted a hospital-based postgraduate education programme on ethical issues including informed consent. As discussed earlier, a validated measure exists to assess the quality of informed consent,34 which enables comparisons

Improvement of the consent process

Plain language aims to simplify explanations such that the meaning is clear to a readership with varying reading experience and abilities. A clear and simple message is likely to be understood by more people than a message with complex wording.

Plain language is important during the consent discussion. The discussion allows for checking of understanding—an important advantage over a form, however simply it is written. Panel 2 is a checklist for clear communication.

Use of familiar words and ideas

Most trial sponsors and investigators tend to use technical language. However, research participants might have poor or incomplete understanding of medical or research terms. Furthermore, some trial-related terms such as “protocol”, “open-label”, and “subsequent” might be understood poorly.66

If possible, terms that are likely to be familiar to people without specialised health knowledge should be used. Writing that includes familiar vocabulary and ideas is easy to read and comprehend.67

Some

Suggestions for the consent discussion

Extended discussions between study staff and research participants might improve patient understanding. Further research is needed on the content of, and other matters around, consent discussions.57 Aaronson and colleagues58 assessed patients with cancer who were considering participation in phase II or III studies. Patients received standard consent discussions, with or without a subsequent nurse telephone contact. Those who had the additional telephone discussion were more informed about

Conclusion

“Making sure that patients are fully informed before they agree to be included in any randomized clinical trial has been, and continues to be, an immense challenge for all who are concerned with the ethical advancement of science”.76

Many studies have assessed the language of consent. Recently, they have focused on the content and particularly the language of the written-consent form. However, conclusions such as those reached by Flory and Emanuel57 reinforce the importance of discussion

Search strategy and selection criteria

Data for this review were identified by searches of Medline, PsychInfo, and CINAHL and from references of relevant articles using combinations of the search terms: “clinical trials”; “informed consent”; “consent forms”; “comprehension”; “communication”; “reading”; “health education”; “physician–patient relations”; and “neoplasms”. Abstracts and reports from meetings were included only when they related directly to previously published work. Only papers published in English between 1980

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