Elsevier

European Journal of Cancer

Volume 44, Issue 17, November 2008, Pages 2627-2633
European Journal of Cancer

Knowledge and understanding among cancer patients consenting to participate in clinical trials

https://doi.org/10.1016/j.ejca.2008.08.013Get rights and content

Abstract

The aim of this study was to explore the fulfilment of the requirements of informed consent in patients participating in cancer clinical trials. All patients consenting to a phase II or III clinical trial during one year were included (n = 325, 176 women, 54%). Data were collected by a questionnaire, Quality of Informed Consent. The response rate was 87%. High levels of knowledge (>80%) were found for items concerning voluntariness, randomisation, benefits for future patients, participation in a research trial, and the right to withdraw. Less than 50% responded correctly to items about risks associated with the trial, the unproven nature of the trial and issues about insurances. High levels of perceived understanding were reported. Despite high levels of knowledge and perceived understanding in the majority of elements of informed consent, improvements are warranted regarding knowledge about risks, the unproven nature of the treatment and the duration of treatment.

Introduction

Therapeutic development within oncology requires the participation of patients in clinical trials. It is mandatory, according to both international and national guidelines and laws, that every patient who participates in research gives a written informed consent before inclusion. The principles of informed consent are based on the Declaration of Helsinki.1 The practice of the informed consent has developed from multiple disciplines, such as health professions, the law and moral philosophy.2 Formal obligations and requirements for informed consent evolved from the standards governing both clinical medicine and human research. In the context of research, informed consent developed in parallel with a informed consent to medical treatment.

Five elements constitute informed consent: voluntarism, capacity, disclosure, understanding and decision.2, 3, 4 Voluntarism requires that the patient is free from coercions and persuasions in decision-making. Capacity refers to the patients’ ability in making health care decisions, in terms of ability to make choices, understand relevant information, comprehend the situation and its consequences and to rationally process the information. Competence is an aspect of capacity that refers to the patients’ legal status in making decisions. Disclosure involves giving the patient the relevant information concerning the nature and purpose of the treatment, as well as information about the risks, potential benefits and available alternatives. Understanding requires that the patient comprehends the information given and perceive this information as relevant to her situation. Decision refers to the patient accepting the proposed treatment.

Many studies reveal insufficient understanding by patients participating in research studies.5, 6, 7, 8 Research participants may perceive themselves as well informed but nevertheless hold significant misunderstandings.7, 9 Studies also show that investigators/physicians rarely check patients understanding of the information given.6, 8, 10

A clinical trial unit (CTU) has been running at the Department of Oncology, Karolinska University Hospital since 1996. Phase I, II, III and IV trials are conducted at the CTU. The unit coordinates between 110 and 120 clinical studies at three clinical sites. In general about 20 studies are in planning phase, 50 studies open for inclusion, 50 studies with patients under treatment or follow-up. The majority of the trials are phase II and III studies. The unit is staffed with 17 research nurses who serve as coordinators for the clinical trial teams and they support the bedside staff in the conduct of the trial by preparing a summary of the study protocol including the definition of tasks and responsibilities of each member of the clinical trial team. Patients usually get their initial information, oral and written, about a clinical trial from their physician at an appointment at the Department of Oncology. It is recommended, but not mandatory, that a research nurse participates on that occasion. Patients are encouraged to discuss the information with friends and/or relatives and to return to the physician and/or the research nurse later with additional questions before making a decision on whether to participate in the trial or not. There is a standard operating procedure (SOP), describing physicians’ and research nurses’ responsibilities, in accordance with guidelines and laws, including the physician’s duty to make sure that the patient understand the implications of participating in the trial.

All patients participating in trials conducted at the CTU sign informed consent forms. The aim this study was to explore the fulfilment of the requirements of informed consent in patients participating in clinical trials at the CTU. Gender and diagnostic groups were also compared with respect to knowledge.

The study was approved by the Regional Ethical Review Board, Stockholm (2005/604-31/3).

Section snippets

Subjects

Patients who had been informed in Swedish about a phase II or a phase III clinical trial at the Department of Oncology, Karolinska University Hospital between September 2005 and September 2006, aged 18 years or older, and had signed a consent form were included.

Procedure

Data collection started in September 2005 and continued for one year. Research nurses at the Clinical Trial Unit provided the coordinator of this study with data collected on patients included in phase II or III trials at the Department

Results

Questionnaires were mailed to 325 patients, 176 women (54%), who had consented to participate in one of the 35 clinical trials open for inclusion during the study period. A total of 282 patients responded (87%). Demographic characteristics of respondents are shown in Table 1. The number of respondents included in phase II or III trials according to diagnosis are presented in Table 2. Of the non-respondents, 2 questionnaires were returned to sender, 10 patients returned uncompleted

Discussion

In this study, the majority of the participants perceived themselves as well informed. High levels of knowledge were found for some items while our results revealed a lack of knowledge with respect to other items required for informed consent.

The proportion of patients responding correctly to the items about knowledge in part A varied. Most patients were aware that they were participating in research and that participation was voluntary. Surprisingly, over 90% responded correctly that the main

Conflict of interest statement

None declared.

Acknowledgements

This study was supported by the Swedish Cancer Society and the Stockholm County Council. We sincerely thank the patients who have contributed to this study, the nurses at the Clinical Trial Unit, Department of Oncology, Karolinska University Hospital. We also want to thank Urban Nylén, Mats Strömberg, Louise von Essen, Ruth Wilson Kärnell, and Jeffery Yachnin all at the Department of Oncology for valuable contributions to the translation of the QuIC.

References (15)

There are more references available in the full text version of this article.

Cited by (52)

  • China's cancer patients’ perceptions, attitudes and participation in clinical trials of complementary and alternative medicine: A multi-center cross-sectional study

    2018, European Journal of Integrative Medicine
    Citation Excerpt :

    However, many problems still exist in CTs, such as the unproven benefits, potential risks, ethical issues, etc. Furthermore, the perceptions and attitudes of the cancer patients toward CTs are multifarious, which could influence their decisions to participate in CTs [13–17]. Clinical trials of complementary and alternative medicine (CTCAM) are also important, though many CTCAM are not registered [7,18].

  • Patients' knowledge and perceived understanding - Associations with consenting to participate in cancer clinical trials

    2016, Contemporary Clinical Trials Communications
    Citation Excerpt :

    “Knowledge” and “perceived understanding” were assessed by a questionnaire developed based on the requirements of informed consent in cancer clinical trials [18]. This is a brief, valid and reliable instrument, and the Swedish translation has been validated [20]. The “knowledge” part can be considered to objectively measure knowledge about the drug trial that the patient is considering to participate in or not.

View all citing articles on Scopus
View full text