Participants’ understanding of informed consent in clinical trials over three decades: systematic review and meta-analysis

Abstract

ObjectiveTo estimate the proportion of participants in clinical trials who understand different components of informed consent.MethodsRelevant studies were identified by a systematic review of PubMed, Scopus and Google Scholar and by manually reviewing reference lists for publications up to October 2013. A meta-analysis of study results was performed using a random-effects model to take account of heterogeneity.FindingsThe analysis included 103 studies evaluating 135 cohorts of participants. The pooled proportion of participants who understood components of informed consent was 75.8% for freedom to withdraw at any time, 74.7% for the nature of study, 74.7% for the voluntary nature of participation, 74.0% for potential benefits, 69.6% for the study’s purpose, 67.0% for potential risks and side-effects, 66.2% for confidentiality, 64.1% for the availability of alternative treatment if withdrawn, 62.9% for knowing that treatments were being compared, 53.3% for placebo and 52.1% for randomization. Most participants, 62.4%, had no therapeutic misconceptions and 54.9% could name at least one risk. Subgroup and meta-regression analyses identified covariates, such as age, educational level, critical illness, the study phase and location, that significantly affected understanding and indicated that the proportion of participants who understood informed consent had not increased over 30 years.ConclusionThe proportion of participants in clinical trials who understood different components of informed consent varied from 52.1% to 75.8%. Investigators could do more to help participants achieve a complete understanding.

Conhecimento de crianças sobre o termo de assentimento livre e esclarecido

“…Studies show that this process has been insufficient to achieve its ethical goal, since children and adolescents do not understand a great deal of the information about the research in which they are involved 4,[12][13][14][15] . In this sense, obtaining the FPIC from these participants may represent failure of the principle of respect for people 16 , because it only formally fulfills the ethical determination to provide participants with information and clarification about the study.…”

Decision Aids Can Support Cancer Clinical Trials Decisions: Results of a Randomized Trial

“…Although a number of interventions have been developed to improve clinical trial informed consent, nearly all focus exclusively on improving patients' knowledge [6,7]. Even with the implementation of such interventions, a recent meta-analysis found that participant understanding of important concepts essential for informed consent has not increased during the 3 decades of studies examined [4]. To improve cancer clinical trial decision quality, interventions must go beyond knowledge provision to address aspects such as preference deliberation and decision preparedness, guiding patients through the trial decision-making process [6,8].…”

“…Many patients harbor therapeutic misconceptions about the aim of clinical trials [1,2] and overestimate benefits of standard treatment [3]. In a recent meta-analysis of 103 studies, more than 25% of clinical trial participants did not understand the nature of the study they were participating in or the voluntary nature of participation [4]. Only approximately 50%of participants understoodcentral trial concepts such asthe use of placebos or randomization [4].…”

“…In a recent meta-analysis of 103 studies, more than 25% of clinical trial participants did not understand the nature of the study they were participating in or the voluntary nature of participation [4]. Only approximately 50%of participants understoodcentral trial concepts such asthe use of placebos or randomization [4]. Furthermore, members of thegeneralpublic frequently havemisconceptions aboutclinical trials, with nearly half of respondents believing that research participants do not always receive the best possible care [5].…”

Avaliação do processo de consentimento de participantes de pesquisa clínica

“…Esse processo desempenha um papel fundamental no estudo, pois afeta diretamente como os princípios éticos são aplicados na prática (TAM et al, 2015). …”