Knowledge and understanding of information after taking decision to participate or not in a randomized trial of surgery vs radiotherapy among patients with locally advanced prostate cancer – an observational study
DOI:
https://doi.org/10.2340/1651-226X.2025.42218Keywords:
Clinical trials, Prostate cancer, Quality of Informed Consent, EORTC QLQ-INFO25, Satisfaction with informationAbstract
Background and purpose: Informed consent from trial participants is mandatory. In a randomized clinical trial, we investigated (1) differences in knowledge and understanding of trial information between patients who participated and those who refrained, (2) differences in perceptions of information, and (3) differences in satisfaction with the information.
Patients: After the decision about participation in the randomized study, ‘Surgery versus radiotherapy for locally advanced prostate cancer’ (SPCG-15), patients were sent questionnaires (‘Quality of Informed Consent’, EORTC QLQ-INFO25). Patients were categorized in ‘Non-participants’ or ‘Participants’.
Results and interpretation: A total of 80 patients (80%) responded, 68% of non-participants and 95% of participants. Between-group differences in knowledge were found for duration of the trial, insurances in the trial, and if the trial intervention had been proven to be superior. Patients had high levels of knowledge (> 80%) regarding the trial aim, that participation implied research, the right to decline, that future patients benefit from research and, of the randomization procedure. Less than 50% responded correctly concerning risks associated with the trial, the unproven nature of the trial and issues about insurances. Non-participants scored lower concerning duration of trial participation, confidentiality of medical records, treatments and procedures in the trial, and experimental nature of treatments. There were no differences regarding satisfaction with information.
Non-participants and participants did not differ in satisfaction, or in knowledge and understanding of most aspects of the information. Knowledge levels were low in some areas, and thus, it seems to be room for improvement to fulfill the requirements of informed consent.
Downloads
References
World Medical Association. WMA declaration of Helsinki – ethical principles for medical research involving human subjects [Internet]. [cited 2024 Jul 12]. Available from: https://www.wma.net/policies-post/wma-declaration-of-helsinki-ethical-principles-for-medical-research-involving-human-subjects/
Unger JM, Hershman DL, Till C, Minasian LM, Osarogiagbon RU, Fleury ME, et al. “When offered to participate”: a systematic review and meta-analysis of patient agreement to participate in cancer clinical trials. J Natl Cancer Inst. 2021;113:244–57.
https://doi.org/10.1093/jnci/djaa155 DOI: https://doi.org/10.1093/jnci/djaa155
Gul RB, Ali PA. Clinical trials: the challenge of recruitment and retention of participants. J Clin Nurs. 2010;19:227–33.
https://doi.org/10.1111/j.1365-2702.2009.03041.x DOI: https://doi.org/10.1111/j.1365-2702.2009.03041.x
Kaur G, Smyth RL, Williamson P. Developing a survey of barriers and facilitators to recruitment in randomized controlled trials. Trials. 2012;21:218.
https://doi.org/10.1186/1745-6215-13-218 DOI: https://doi.org/10.1186/1745-6215-13-218
Treweek S, Lockhart P, Pitkethly N, Cook J, Kjeldstrom M, Johansen M, et al. Methods to improve recruitment to randomised controlled trials: Cochrane systematic review and meta-analyses. Br Med J Open. 2013;3;e002360.
https://doi.org/10.1136/bmjopen-2012-002360 DOI: https://doi.org/10.1136/bmjopen-2012-002360
Rodríguez-Torres E, González-Pérez MM, Díaz-Pérez C. Barriers and facilitators to the participation of subjects in clinical trials: an overview of reviews. Contemp Clin Trials Commun. 2021;23:100829.
https://doi.org/10.1016/j.conctc.2021.100829 DOI: https://doi.org/10.1016/j.conctc.2021.100829
Brandberg Y, Johansson H, Bergenmar M. Patients’ knowledge and perceived understanding – associations with consenting to participate in cancer clinical trials. Contemp Clin Trials Commun. 2016;2:6–11.
https://doi.org/10.1016/j.conctc.2015.12.001 DOI: https://doi.org/10.1016/j.conctc.2015.12.001
Joffe S, Cook EF, Cleary PD, Clark JW, Weeks JC. Quality of informed consent: a new measure of understanding among research subjects. J Natl Cancer Inst. 2001;93:139–47.
https://doi.org/10.1093/jnci/93.2.139 DOI: https://doi.org/10.1093/jnci/93.2.139
Joffe S, Cook EF, Cleary PD, Clark JW, Weeks JC. Quality of informed consent in cancer clinical trials: a cross- sectional survey. Lancet. 2001;358:1772–7.
https://doi.org/10.1016/S0140-6736(01)06805-2 DOI: https://doi.org/10.1016/S0140-6736(01)06805-2
Bergenmar M, Molin C, Wilking N, Brandberg Y. Knowledge and understanding among cancer patients consenting to participate in clinical trials. Eur J Cancer. 2008;44:2627–33.
https://doi.org/10.1016/j.ejca.2008.08.013 DOI: https://doi.org/10.1016/j.ejca.2008.08.013
Arraras JI, Greimel E, Sezer O, Wei-Chu C, Bergenmar M, Constantini A. An international validation study of the EORTC QLQ-INFO25 questionnaire: an instrument to assess the information given to cancer patients. Eur J Cancer. 2010;46:2726–38.
https://doi.org/10.1016/j.ejca.2010.06.118 DOI: https://doi.org/10.1016/j.ejca.2010.06.118
Thiessen M, Harris D, Tang PA, Raffin Bouchal S, Sinclair S. Examining the development of information needs assessment tools for use in the cancer context: a scoping and critical review. Pall Supp Care. 2024;22(6):2136–48.
https://doi.org/10.1017/S1478951523001232 DOI: https://doi.org/10.1017/S1478951523001232
Bergenmar M, Johansson H, Wilking N, Hatscheck T, Brandberg Y. Audio-recorded information to patients considering participation in cancer clinical trials – a randomized study. Acta Oncol. 2014;53:1197–204.
https://doi.org/10.3109/0284186X.2014.921726 DOI: https://doi.org/10.3109/0284186X.2014.921726
Lidz C, Appelbaum P, Grisso T, Renaud M. Therapeutic misconception and the appreciation of risks in clinical trials. Soc Sci Med. 2004;58:1689–97.
https://doi.org/10.1016/S0277-9536(03)00338-1 DOI: https://doi.org/10.1016/S0277-9536(03)00338-1
Mills EJ, Seely D, Rachlis B. Barriers to participation in clinical trials of cancer: a meta-analysis and systematic review of patient-reported factors. Lancet Oncol. 2006;7:141–8.
https://doi.org/10.1016/S1470-2045(06)70576-9 DOI: https://doi.org/10.1016/S1470-2045(06)70576-9
Grand MM, O’Brian PC. Obstacles to participation in randomised cancer clinical trials: a systematic review of the literature. J Med Imaging Radiat Oncol. 2012;56:31–9.
https://doi.org/10.1111/j.1754-9485.2011.02337.x DOI: https://doi.org/10.1111/j.1754-9485.2011.02337.x
Bell JAH, Balneaves LG. Cancer patient decision making related to clinical trial participation: an integrative review with implications for patients’ relational autonomy. Support Care Cancer. 2015;23:1169–96.
https://doi.org/10.1007/s00520-014-2581-9 DOI: https://doi.org/10.1007/s00520-014-2581-9
Bergenmar M, Johansson H, Wilking N. Levels of knowledge and perceived understanding among participants in cancer clinical trials – factors related to the informed consent procedure. Clin Trials. 2011;8:77–84.
https://doi.org/10.1177/1740774510384516 DOI: https://doi.org/10.1177/1740774510384516
Fletcher C, Flight I, Chapman J, Fennell K, Wilson C. The information needs of adult cancer survivors across the cancer continuum: a scoping review. Patient Educ Couns. 2017;100:383–410.
https://doi.org/10.1016/j.pec.2016.10.008 DOI: https://doi.org/10.1016/j.pec.2016.10.008
Published
How to Cite
Issue
Section
Categories
License
Copyright (c) 2025 Yvonne Brandberg, Olof Akre, Mia Bergenmar
This work is licensed under a Creative Commons Attribution 4.0 International License.
