Comparing the understanding of subjects receiving a candidate malaria vaccine in the United States and Mali

Participants' understanding of informed consent in clinical trials: A systematic review and updated meta-analysis

Obtaining written informed consent from participants before enrolment in a study is essential. A previous study showed that only 50% of the participants in clinical trials understood the components of informed consent, and the methods of participants' understanding of informed consent were controversial. This updated meta-analysis aimed to estimate the proportion of participants in clinical trials who understand the different informed consent components. PubMed, EMBASE, the Cochrane Library, and Scopus were searched till April 2023. Therapeutic misconception, ability to name one risk, knowing that treatments were being compared, and understanding the nature of the study, the purpose of the study, the risks and side-effects, the direct benefits, placebo, randomization, voluntariness, freedom to withdraw, the availability of alternative treatment if withdrawn from the trial, confidentiality, compensation, or comprehension were evaluated. This meta-analysis included 117 studies (155 datasets; 22,118 participants). The understanding of the risks and side-effects was investigated in the largest number of studies (n = 100), whereas comparehension was investigated in the smallest number (n = 11). The highest proportions were 97.5%(95% confidence interval (CI): 97.1-97.9) for confidentiality, 95.9% (95% confidence interval (CI): 95.4-96.4) for compensation, 91.4% (95% CI: 90.7-92.1) for the nature of study, 68.1% (95% CI: 51.6-84.6) for knowing that treatments were being compared, and 67.3% (95% CI: 56.6-78) for voluntary nature of participants. The smallest proportions were the concept of placebo (4.8%, 95%CI: 4.4-5.2) and randomization(39.4%, 95%CI: 38.3-40.4). Our findings suggested that most participants understood the fundamental components of informed consent (study confidentiality, nature, compensation, voluntariness, and freedom to withdraw). The understanding of other components, such as placebo and randomization was less satisfactory.

The reality of informed consent: empirical studies on patient comprehension-systematic review

Background

Informed consent is a basic concept of contemporary, autonomy-based medical practice and facilitates a shared decision-making model for relations between physicians and patients. Thus, the extent to which patients can comprehend the consent they grant is essential to the ethical viability of medicine as it is pursued today. However, research on patients’ comprehension of an informed consent’s basic components shows that their level of understanding is limited.

Methods

Systemic searches of the PubMed and Web of Science databases were performed to identify the literature on informed consent, specifically patients’ comprehension of specific informed consent components.

Results

In total, 14 relevant articles were retrieved. In most studies, few clinical trial participants correctly responded to items that examined their awareness of what they consented to. Participants demonstrated the highest level of understanding (over 50%) regarding voluntary participation, blinding (excluding knowledge about investigators’ blinding), and freedom to withdraw at any time. Only a small minority of patients demonstrated comprehension of placebo concepts, randomisation, safety issues, risks, and side effects.

Conclusions

We found that participants’ comprehension of fundamental informed consent components was low, which is worrisome because this lack of understanding undermines an ethical pillar of contemporary clinical trial practice and questions the viability of patients’ full and genuine involvement in a shared medical decision-making process.

Informed consent procedure in a double blind randomized anthelminthic trial on Pemba Island, Tanzania: do pamphlet and information session increase caregivers knowledge?

BACKGROUND

In clinical research, obtaining informed consent from participants is an ethical and legal requirement. Conveying the information concerning the study can be done using multiple methods yet this step commonly relies exclusively on the informed consent form alone. While this is legal, it does not ensure the participant's true comprehension. New effective methods of conveying consent information should be tested. In this study we compared the effect of different methods on the knowledge of caregivers of participants of a clinical trial on Pemba Island, Tanzania.

METHODS

A total of 254 caregivers were assigned to receive (i) a pamphlet (n = 63), (ii) an oral information session (n = 62) or (iii) a pamphlet and an oral information session (n = 64) about the clinical trial procedures, their rights, benefits and potential risks. Their post-intervention knowledge was assessed using a questionnaire. One group of caregivers had not received any information when they were interviewed (n = 65).

RESULTS

In contrast to the pamphlet, attending an information session significantly increased caregivers' knowledge for some of the questions. Most of these questions were either related to the parasite (hookworm) or to the trial design (study procedures).

CONCLUSIONS

In conclusion, within our trial on Pemba Island, a pamphlet was found to not be a good form of conveying clinical trial information while an oral information session improved knowledge. Not all caregivers attending an information session responded correctly to all questions; therefore, better forms of communicating information need to be found to achieve a truly informed consent.

A Comparison of the Quality of Informed Consent for Clinical Trials of an Experimental Hookworm Vaccine Conducted in Developed and Developing Countries

Informed consent is one of the principal ethical requirements of conducting clinical research, regardless of the study setting. Breaches in the quality of the informed consent process are frequently described in reference to clinical trials conducted in developing countries, due to low levels of formal education, a lack of familiarity with biomedical research, and limited access to health services in these countries. However, few studies have directly compared the quality of the informed consent process in developed and developing countries using the same tool and in similar clinical trials. This study was conducted to compare the quality of the informed consent process of a series of clinical trials of an investigational hookworm vaccine that were performed in Brazil and the United States. A standardized questionnaire was used to assess the ethical quality of the informed consent process in a series of Phase 1 clinical trials of the Na-GST-1/Alhydrogel hookworm vaccine that were conducted in healthy adults in Brazil and the United States. In Brazil, the trial was conducted at two sites, one in the hookworm non-endemic urban area of Belo Horizonte, Minas, and one in the rural, resource-limited town of Americaninhas, both in the state of Minas Gerais; the American trial was conducted in Washington, DC. A 32-question survey was administered after the informed consent document was signed at each of the three trial sites; it assessed participants’ understanding of information about the study presented in the document as well as the voluntariness of their decision to participate. 105 participants completed the questionnaire: 63 in Americaninhas, 18 in Belo Horizonte, and 24 in Washington, DC. Overall knowledge about the trial was suboptimal: the mean number of correct answers to questions about study objectives, methods, duration, rights, and potential risks and benefits, was 45.6% in Americaninhas, 65.2% in Belo Horizonte, and 59.1% in Washington, DC. Although there was no difference in the rate of correct answers between participants in Belo Horizonte and Washington, DC, there was a significant gap between participants at these two locations compared to Americaninhas (p = 0.0002 and p = 0.0001, respectively), which had a lower percentage of correct answers. Attitudes towards participating in the clinical trial also differed by site: while approximately 40% had doubts about participating in Washington, DC and Belo Horizonte, only 1.5% had concerns in Americaninhas. Finally, in Belo Horizonte and Washington, high percentages cited a desire to help others as motivation for participating, whereas in Americaninhas, the most common reason for participating was personal interest (p = 0.001). Understanding of information about a Phase 1 clinical trial of an experimental hookworm vaccine following informed consent was suboptimal, regardless of study site. Although overall there were no differences in knowledge between Brazil and the US, a lower level of understanding about the trial was seen in participants at the rural, resource-limited Brazilian site. These findings demonstrate the need for educational interventions directed at potential clinical trial participants, both in developing and developed countries, in order to improve understanding of the informed consent document.

Informed consent is an essential element of the ethical conduct of clinical trials of new vaccines, regardless of the study setting. However, the quality of informed consent is often suboptimal. Some research has suggested that the quality of the informed consent process may be reduced in resource-limited areas compared to developed country settings. To test this, we conducted a study of the quality of the informed consent process in two similar Phase 1 clinical trials of the Na-GST-1/Alhydrogel hookworm vaccine that were conducted in healthy adult volunteers in Brazil and in the United States. In Brazil, the trial was conducted at two sites, one a large urban area (Belo Horizonte), and the other a rural, resource-limited region of the state of Minas Gerais; in the United States, the trial was conducted in Washington, DC. A structured questionnaire was administered after the informed consent document was signed at each of the three clinical trial sites, which tested understanding about the information contained in the document and attitudes toward the volunteers’ participation in the clinical trial. The results indicate that there were no substantial differences between the overall quality of the informed consent obtained from participants in the United States and in Brazil. However, a significant association was found between the particular site where the trial was conducted and the quality of the informed consent process, with residents of the site in rural Brazil having the lowest percentage of correct answers on the informed consent questionnaire. The informed consent process should therefore take into account the specific characteristics of the population in which the trial is being conducted.

The Challenges of Research Informed Consent in Socio-Economically Vulnerable Populations: A Viewpoint From the Democratic Republic of Congo

In medical research, the ethical principle of respect for persons is operationalized into the process of informed consent. The consent tools should be contextualized and adapted to the different socio-cultural environment, especially when research crosses the traditional boundaries and reaches poor communities. We look at the challenges experienced in the malaria Quinact trial, conducted in the Democratic Republic of Congo, and describe some lessons learned, related to the definition of acceptable representative, the role of independent witness and the impact of socio-economic vulnerability. To ensure children's protection, consent is required by the parents or, in their absence, by a legally mandated representative. In our setting, children's responsibility is often entrusted permanently or temporarily to relatives or friends without a tribunal mandate. Hence, a notion of 'culturally acceptable representative' under supervision of the local Ethics Committee may be more suitable. To ensure protection of illiterate subjects, an independent witness is required to confirm that the consent was freely given. However, in low-literacy contexts, potential witnesses often don't have any previous relationship with patient and there may be power-unbalance in their relationship, rather than genuine dialogue. In poor communities, trial participation may be seen as an opportunity to secure access to healthcare. Poverty may also lead to 'competition' to access the research-related benefits, with a risk of disturbance at societal or household level. Adjusting consent procedures to sociocultural and socioeconomic realities is essential for fulfilling the underlying ethical principles. This requires a collaborative dialogue between researchers, regulators and ethics committees.

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

OBJECTIVE

To estimate the proportion of participants in clinical trials who understand different components of informed consent.

METHODS

Relevant 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.

FINDINGS

The 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.

CONCLUSION

The 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.

[Knowledge and willingness to participate in research: a descriptive study of volunteers in a clinical trial]

The aim of this study was to evaluate volunteers' knowledge of the information on the free informed consent form and their willingness to participate in a clinical trial. This was a quantitative, descriptive, cross-sectional study conducted in November 2011 with subjects from a clinical trial in Americaninhas, northeast Minas Gerais State, Brazil. A convenience sample included 143 adults of both sexes, 18 to 45 years of age. A structured questionnaire was applied one week after signing the free informed consent form. Most participants signed the free informed consent without sufficient knowledge of the research information and were influenced in their decision to participate in the trial. The authors conclude that signing the free informed consent form fails to express all participants' autonomy in clinical trials.

Informed consent comprehension in African research settings

OBJECTIVE

Previous reviews on participants' comprehension of informed consent information have focused on developed countries. Experience has shown that ethical standards developed on Western values may not be appropriate for African settings where research concepts are unfamiliar. We undertook this review to describe how informed consent comprehension is defined and measured in African research settings.

METHODS

We conducted a comprehensive search involving five electronic databases: Medline, Embase, Global Health, EthxWeb and Bioethics Literature Database (BELIT). We also examined African Index Medicus and Google Scholar for relevant publications on informed consent comprehension in clinical studies conducted in sub-Saharan Africa. 29 studies satisfied the inclusion criteria; meta-analysis was possible in 21 studies. We further conducted a direct comparison of participants' comprehension on domains of informed consent in all eligible studies.

RESULTS

Comprehension of key concepts of informed consent varies considerably from country to country and depends on the nature and complexity of the study. Meta-analysis showed that 47% of a total of 1633 participants across four studies demonstrated comprehension about randomisation (95% CI 13.9-80.9%). Similarly, 48% of 3946 participants in six studies had understanding about placebo (95% CI 19.0-77.5%), while only 30% of 753 participants in five studies understood the concept of therapeutic misconception (95% CI 4.6-66.7%). Measurement tools for informed consent comprehension were developed with little or no validation. Assessment of comprehension was carried out at variable times after disclosure of study information. No uniform definition of informed consent comprehension exists to form the basis for development of an appropriate tool to measure comprehension in African participants.

CONCLUSIONS

Comprehension of key concepts of informed consent is poor among study participants across Africa. There is a vital need to develop a uniform definition for informed consent comprehension in low literacy research settings in Africa. This will be an essential step towards developing appropriate tools that can adequately measure informed consent comprehension. This may consequently suggest adequate measures to improve the informed consent procedure.

The quality of informed consent: mapping the landscape. A review of empirical data from developing and developed countries

OBJECTIVE

Some researchers claim that the quality of informed consent of clinical research participants in developing countries is worse than in developed countries. To evaluate this assumption, we reviewed the available data on the quality of consent in both settings.

METHODS

We conducted a comprehensive PubMed search, examined bibliographies and literature reviews, and consulted with international experts on informed consent in order to identify studies published from 1966 to 2010 that used quantitative methods, surveyed participants or parents of paediatric participants in actual trials, assessed comprehension and/or voluntariness, and did not involve testing particular consent interventions. Forty-seven studies met these criteria. We compared data about participant comprehension and voluntariness. The paucity of data and variation in study methodology limit comparison and preclude statistical aggregation of the data.

RESULTS AND DISCUSSION

This review shows that the assertion that informed consent is worse in developing countries than in developed countries is a simplification of a complex picture. Despite the limitations of comparison, the data suggest that: (1) comprehension of study information varies among participants in both developed and developing countries, and comprehension of randomisation and placebo controlled designs is poorer than comprehension of other aspects of trials in both settings; and (2) participants in developing countries appear to be less likely than those in developed countries to say they can refuse participation in or withdraw from a trial, and are more likely to worry about the consequences of refusal or withdrawal.