Comprehension of informed consent information by young-old through old-old volunteers

Longitudinal assessment of an Ebola vaccine trial understanding among healthcare providers in the Democratic Republic of the Congo

BACKGROUND

The long-term retention of information disclosed during the informed consent in clinical trials lasting over a year cannot be guaranteed for all volunteers. This study aimed to assess the level of participants' retention and understanding of the trial information after two years of participation in a vaccine trial.

METHODS

In total, 699 health care providers (HCPs) and frontline workers were enrolled in the EBL2007 vaccine trial conducted between February 2019 and September 2022 in the Health District of Boende, Democratic Republic of the Congo (DRC). Individual scores obtained from a questionnaire (test of understanding, TOU), specifically designed to assess the understanding of the consent at baseline, were collected before the clinical trial started and at one-year and two-year intervals.

RESULTS

TOU scores were high in the beginning of the trial (median TOU = 10/10), but significantly decreased in both the first and second years following (median TOU = 8/10 in year 1 and median TOU = 9/10 in year 2, p-value < 0.0001). The decrease in scores was significantly higher among individuals with occupations requiring shorter education such as midwives (median TOU = 7/10 in year 1 and 8/10 in year 2, pvalue = 0.025). Furthermore, older participants exhibited poorer retention of information compared to younger individuals (median TOU = 8/10 vs 9/10, p-value = 0.007).

CONCLUSION

We observed a significant decline in the informational knowledge of informed consent, specifically in terms of basic knowledge on the study vaccine and trial procedures. As participant safety and understanding is a paramount ethical concern for researchers, it is crucial for participants to fully comprehend the study's objectives and potential risks. Therefore, our findings suggest the need for clinical researchers to re-explain participants to optimize the protection of their rights and wellbeing during the research.

Facilitating Informed Permission/Assent/Consent in Pediatric Clinical Trials

Individuals approached to participate in human subjects research, irrespective of age, must be completely apprised of the study, and researchers must ensure that the information is understood to the fullest extent possible, prior to decision making. However, evolving regulatory and institutional requirements have led to permission/assent/consent (PAC) forms that are unnecessarily complex, serving only to exacerbate the challenges associated with communicating this important information to prospective participants. At greatest risk are children and other individuals with low literacy, limited English proficiency, and diminished mental capacity, populations all too often neglected in clinical research. This paper examines various strategies that have been evaluated to facilitate informed PAC, drawing on experiences across a broad array of populations whose needs overlap with those of children. These strategies range from simplifying PAC forms for readability and creating multimedia PAC delivery tools to actively engaging participants on their understanding of PAC elements by leveraging testing, rewards, and third-party communications. Notably, the findings from strategies that have been explored in more than one setting are uniformly mixed with respect to their ability to improve comprehension, underscoring the challenges that persist in designing, implementing, and objectively examining strategies intended to facilitate informed PAC. However, these studies do serve to highlight efforts that may reduce anxiety around, and increase the satisfaction of participants with, the PAC process. Ultimately, accommodating a diverse participant pool will require the consideration, and continual refinement, of various PAC strategies along with the engagement of team members who are intimately familiar with these populations.

Permission form synopses to improve parents' understanding of research: a randomized trial

OBJECTIVE

We hypothesized that, among parents of potential neonatal research subjects, an accompanying cover sheet added to the permission form (intervention) would increase understanding of the research, when compared to a standard form (control).

STUDY DESIGN

This pilot study enrolled parents approached for one of two index studies: one randomized trial and one observational study. A one-page cover sheet described critical study information. Families were randomized 1:1 to receive the cover sheet or not. Objective and subjective understanding and satisfaction were measured.

RESULTS

Thirty-two parents completed all measures (17 control, 15 intervention). There were no differences in comprehension score (16.8±5.7 vs 16.3±3.5), subjective understanding (median 6 vs 6.5), or overall satisfaction with consent (median 7 vs 6.5) between control and intervention groups (all P>0.50).

CONCLUSION

A simplified permission form cover sheet had no effect on parents' understanding of studies for which their newborns were being recruited.

A randomized trial comparing concise and standard consent forms in the START trial

BACKGROUND

Improving the effectiveness and efficiency of research informed consent is a high priority. Some express concern about longer, more complex, written consent forms creating barriers to participant understanding. A recent meta-analysis concluded that randomized comparisons were needed.

METHODS

We conducted a cluster-randomized non-inferiority comparison of a standard versus concise consent form within a multinational trial studying the timing of starting antiretroviral therapy in HIV+ adults (START). Interested sites were randomized to standard or concise consent forms for all individuals signing START consent. Participants completed a survey measuring comprehension of study information and satisfaction with the consent process. Site personnel reported usual site consent practices. The primary outcome was comprehension of the purpose of randomization (pre-specified 7.5% non-inferiority margin).

RESULTS

77 sites (2429 participants) were randomly allocated to use standard consent and 77 sites (2000 participants) concise consent, for an evaluable cohort of 4229. Site and participant characteristics were similar for the two groups. The concise consent was non-inferior to the standard consent on comprehension of randomization (80.2% versus 82%, site adjusted difference: 0.75% (95% CI -3.8%, +5.2%)); and the two groups did not differ significantly on total comprehension score, satisfaction, or voluntariness (p>0.1). Certain independent factors, such as education, influenced comprehension and satisfaction but not differences between consent groups.

CONCLUSIONS

An easier to read, more concise consent form neither hindered nor improved comprehension of study information nor satisfaction with the consent process among a large number of participants. This supports continued efforts to make consent forms more efficient.

TRIAL REGISTRATION

Informed consent substudy was registered as part of START study in clinicaltrials.gov #NCT00867048, and EudraCT # 2008-006439-12.

Informed Assent Recall Among Adolescents in Substance Use Disorder Treatment Research

Evidence suggests that vulnerable populations such as substance users, those involved in the criminal justice system, and those with cognitive deficits often fail to recall information regarding the informed assent process. This study investigated correlates of assent quiz errors (AQE) among adolescents enrolling in a substance use disorder treatment study.

METHOD

Adolescents (age 13-19) entering substance use treatment completed a standard informed consent procedure to participate in a longitudinal research study, followed by a brief 6-item assent quiz.

RESULTS

Informed assent quiz errors were lower in this study relative to those observed in the adult literature. Being male and having lower treatment resistance was associated with making an AQE. Both days of marijuana use and days spent in the criminal justice system were associated with AQE. Hyperactivity-impulsivity approached significance (p = .057) but was not a correlate of AQE.

CONCLUSION

Those collecting assent should be aware that heavily-using males involved in the criminal justice system are prone to make more errors, and should use procedures such as assent quizzes to enhance their understanding of study procedures. Future research should investigate the impact of motivation and consider using experimental designs to test adolescent recall of study procedures under various assenting conditions.

Difficult behaviors in the emergency department: a cohort study of housed, homeless and alcohol dependent individuals

Background

This study contrasted annual rates of difficult behaviours in emergency departments among cohorts of individuals who were homeless and low-income housed and examined predictors of these events.

Methods

Interviews in 1999 with men who were chronically homeless with drinking problems (CHDP) (n = 50), men from the general homeless population (GH) (n = 61), and men residing in low-income housing (LIH) (n = 58) were linked to catchment area emergency department records (n = 2817) from 1994 to 1999. Interview and hospital data were linked to measures of difficult behaviours.

Results

Among the CHDP group, annual rates of visits with difficult behaviours were 5.46; this was 13.4 (95% CI 10.3–16.5) and 14.3 (95% CI 11.2–17.3) times higher than the GH and LIH groups. Difficult behaviour incidents included physical violence, verbal abuse, uncooperativeness, drug seeking, difficult histories and security involvement. Difficult behaviours made up 57.54% (95% CI 55.43–59.65%), 24% (95% CI 19–29%), and 20% (95% CI 16–24%) of CHDP, GH and LIH visits. Among GH and LIH groups, 87% to 95% were never involved in verbal abuse or violence. Intoxication increased all difficult behaviours while decreasing drug seeking and leaving without being seen. Verbal abuse and violence were less likely among those housed, with odds ratios of 0.24 (0.08, 0.72) and 0.32 (0.15, 0.69), respectively.

Conclusions

Violence and difficult behaviours are much higher among chronically homeless men with drinking problems than general homeless and low-income housed populations. They are concentrated among subgroups of individuals. Intoxication is the strongest predictor of difficult behaviour incidents.

Improving understanding in the research informed consent process: a systematic review of 54 interventions tested in randomized control trials

Background

Obtaining informed consent is a cornerstone of biomedical research, yet participants comprehension of presented information is often low. The most effective interventions to improve understanding rates have not been identified.

Purpose

To systematically analyze the random controlled trials testing interventions to research informed consent process. The primary outcome of interest was quantitative rates of participant understanding; secondary outcomes were rates of information retention, satisfaction, and accrual. Interventional categories included multimedia, enhanced consent documents, extended discussions, test/feedback quizzes, and miscellaneous methods.

Methods

The search spanned from database inception through September 2010. It was run on Ovid MEDLINE, Ovid EMBASE, Ovid CINAHL, Ovid PsycInfo and Cochrane CENTRAL, ISI Web of Science and Scopus. Five reviewers working independently and in duplicate screened full abstract text to determine eligibility. We included only RCTs. 39 out of 1523 articles fulfilled review criteria (2.6%), with a total of 54 interventions. A data extraction form was created in Distiller, an online reference management system, through an iterative process. One author collected data on study design, population, demographics, intervention, and analytical technique.

Results

Meta-analysis was possible on 22 interventions: multimedia, enhanced form, and extended discussion categories; all 54 interventions were assessed by review. Meta-analysis of multimedia approaches was associated with a non-significant increase in understanding scores (SMD 0.30, 95% CI, -0.23 to 0.84); enhanced consent form, with significant increase (SMD 1.73, 95% CI, 0.99 to 2.47); and extended discussion, with significant increase (SMD 0.53, 95% CI, 0.21 to 0.84). By review, 31% of multimedia interventions showed significant improvement in understanding; 41% for enhanced consent form; 50% for extended discussion; 33% for test/feedback; and 29% for miscellaneous.Multiple sources of variation existed between included studies: control processes, the presence of a human proctor, real vs. simulated protocol, and assessment formats.

Conclusions

Enhanced consent forms and extended discussions were most effective in improving participant understanding. Interventions of all categories had no negative impact on participant satisfaction or study accrual. Identification of best practices for studies of informed consent interventions would aid future systematic comparisons.

Corrected Feedback: A Procedure to Enhance Recall of Informed Consent to Research among Substance Abusing Offenders

This study examined the efficacy of corrected feedback for improving consent recall throughout the course of an ongoing longitudinal study. Participants (N = 135) were randomly assigned to either a corrected feedback or a no-feedback control condition. Participants completed a consent quiz 2-weeks after consenting to the host study and at months 1, 2, and 3. The corrected feedback group received corrections to erroneous responses and the no-feedback control group did not. The feedback group displayed significantly greater recall overall and in specific content areas (i.e., procedures, protections, risks/benefits). Results support the use of corrected feedback for improving consent recall.

Improvement of informed consent and the quality of consent documents

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.

Are We Misjudging How Well Informed Consent Forms are Read?

Understanding that informed consent forms are provided to be read and comprehended, this study compares the research assistant's perception of comprehension with the actual time potential participants spend reading their consent form. After providing information verbally to two samples of women, research assistants observed as the women reviewed and signed the consent form recording the time spent reading and the assistant's impression of reading behavior. Over half of the women “read” their consent forms in thirty seconds or less before signing. Despite the brief time participants actually read, research assistants reported that 38%–74% (depending on the sample) appeared to have completely read the forms. Research to determine if timing aids will improve research assistants' assessment of participant reading behaviors should be considered.

Assessment of decision-making capacity in older adults: an emerging area of practice and research

The convergence of the aging of our society, the increase in blended families, and an enormous intergenerational transfer of wealth has greatly expanded the incidence and importance of capacity assessment of older adults. In this article we discuss the emergence of capacity assessment as a distinct field of study. We review research efforts in two domains: medical decision-making capacity and financial capacity. Existing research in these two areas provides a first pass at many key questions related to capacity assessment, but additional studies that replicate, extend, and improve on this research are urgently needed. An agenda for future is detailed that recommends studies of a wide range of capacity constructs, focusing on clinical markers of diminished capacity, methods to improve clinical assessment, and the many intersections of law and clinical practice.

Assessment of Capacity to Consent to Treatment: Challenges, the "ACCT" Approach, Future Directions

OBJECTIVE: To review approaches to assessing consent capacity in patients with neurocognitive or neuropsychiatric illness; to summarize the rationale behind our structured interview for consent capacity; and to outline questions for future research. METHOD: After reviewing legal and clinical literature, and empirically comparing three leading consent capacity instruments, we developed the Assessment of Capacity to Consent to Treatment (ACCT) interview and administered it to adults with dementia (n=20), schizophrenia (n=20), and controls (n=19). Capacity ratings by primary care clinicians and experts blind to the patients' status were obtained for a subsample. RESULTS: Interscorer reliability was r=.90; internal consistency reliability was .α=96. ACCT scores agreed 82% of the time (kappa = .44; p<.01) with primary care clinician ratings of capacity and 75% of the time (kappa = .50; p<.05) with expert ratings of capacity. Patients with dementia and schizophrenia could express treatment choices but performed worse than controls on measures of understanding, appreciation as problems with foresight, rational reasoning, and values-based reasoning. Only patients with schizophrenia performed worse on a measure of appreciation as problems with distrust. CONCLUSION: The method of assessing consent capacity described here has adequate reliability and validity, and may provide a useful starting point for clinicians and researchers. Many questions remain about the nature of consent capacity, its component constructs, and the meaning of instrument versus clinician ratings of capacity. Future adaptations, particularly in the assessment of appreciation and reasoning, and additional studies in more diverse samples, are needed.

Empirical advances in the assessment of the capacity to consent to medical treatment: Clinical implications and research needs

The clinical evaluation of capacity to consent to treatment occurs in the medical setting and is based on legal foundations of informed consent and capacity. Clinical judgment is still the "gold standard" for capacity determination, although it can be unreliable. In the past 10 years the empirical basis for these assessments has been advanced considerably by the introduction of a number of instruments designed to assess capacity to consent to treatment. In this paper, we review studies, mostly with older adult populations, that consider the cognitive and non-cognitive correlates of consent capacity, rates of impaired capacity in various patient groups, the relation of instrument-based to clinician-based capacity assessment, and the inter-rater and test-retest reliability of consent capacity assessment. We also overview key research focusing on factors influencing, and procedural and processing variables involved in, medical decision-making. We conclude that these studies have yielded quite varied results, and promote no consensus regarding the reliability and validity of instrument-based consent capacity assessment. Overall, the results of these studies provide some guidance for clinicians, but, at present, practitioners should view these instruments as supplemental resources rather than benchmarks for assessment. However, this first generation of instruments provides a good foundation for future research, which should continue to systematically study aspects of reliability and validity, most especially construct validity, in well-defined patient populations.

Use of a modified informed consent process among vulnerable patients: a descriptive study

BACKGROUND

Little is known about patient characteristics associated with comprehension of consent information, and whether modifications to the consent process can promote understanding.

OBJECTIVE

To describe a modified research consent process, and determine whether literacy and demographic characteristics are associated with understanding consent information.

DESIGN

Descriptive study of a modified consent process: consent form (written at a sixth-grade level) read to participants, combined with 7 comprehension questions and targeted education, repeated until comprehension achieved (teach-to-goal).

PARTICIPANTS

Two hundred and four ethnically diverse subjects, aged > or = 50, consenting for a trial to improve the forms used for advance directives.

MEASUREMENTS

Number of passes through the consent process required to achieve complete comprehension. Literacy assessed in English and Spanish with the Short Form Test of Functional Health Literacy in Adults (scores 0 to 36).

RESULTS

Participants had a mean age of 61 years and 40% had limited literacy (s-TOHFLA<23). Only 28% of subjects answered all comprehension questions correctly on the first pass. After adjustment, lower literacy (P=.04) and being black (P=.03) were associated with requiring more passes through the consent process. Not speaking English as a primary language was associated with requiring more passes through the consent process in bivariate analyses (P<.01), but not in multivariable analyses (P>.05). After the second pass, most subjects (80%) answered all questions correctly. With a teach-to-goal strategy, 98% of participants who engaged in the consent process achieved complete comprehension.

CONCLUSIONS

Lower literacy and minority status are important determinants of understanding consent information. Using a modified consent process, little additional education was required to achieve complete comprehension, regardless of literacy or language barriers.

Long term clinical trials: how much information do participants retain from the informed consent process?

Previous studies report mixed results about how much information study participants actually can read, understand and retain after completing the informed consent process; fewer studies have examined disparities in the retention and recall of information by patient factors, such as age, education, and race. Not retaining or being able to recall information from the informed consent process has potentially important ethical and legal implications and consequences for research quality and integrity, especially when found in populations that commonly are underserved or underrepresented in clinical trials. To determine how much basic knowledge participants finishing a five-year, multi-center, double-blinded randomized, placebo-controlled clinical trial had about the study, participants (n=1,789) were asked at their final follow-up visit three multiple-choice questions: (1) the study's purpose; (2) the name of the medication under investigation; (3) the main side effect of the medication. The associations between knowledge of these fundamental details and participant social and demographic factors were investigated. A majority of participants correctly recalled the study's purpose (64.7%) and medication (79.6%), but few correctly reported the main side effect (31.1%). In spite of relatively high recall for study purpose and medication, disparities by age, education and race exist. Increasing age was significantly associated with higher odds of incorrectly recalling both the study purpose and the name of the study medication. Likewise those with less than a high school education were more likely to incorrectly identify the study's purpose and the name of the study medication. Black and other non-white race or ethnic groups were more than two and a half times as likely to incorrectly identify the study's purpose. These findings suggest that even the most basic information may not be understood or retained by important subgroups of patients enrolled in clinical trials. Implementing effective strategies, such as additional time and effort for consent or repetition of study information, may be necessary in order to assure ethical and valid consent.

Decisional capacity in mental illness and substance use disorders: empirical database and policy implications

Debates on decisional capacity in people with mental illnesses or substance use disorders have tended to be heated. Yet, they are often based not on empirical data but on personal opinions and experiences. The empirical database in this area is quite limited, but has been growing in recent years. The following discussion focuses on relevant clinical investigations. We consider variations across and within different diagnoses, barriers to decision-making, methods for assessing capacity-interview versus instruments, choosing from among different capacity instruments, decisional capacity-is it a state or a trait?, triggers for assessment of decisional capacity, methods for enhancing capacity, and decisional capacity in people with substance use disorders. Finally, we discuss some relevant health policy recommendations.

The doctor's duty to the elderly patient in clinical trials

The ethical principles of beneficence (or non-maleficence), respect for persons and justice apply to both good medical practice and clinical research. Doctors have a duty to offer to their patients, of all ages, the opportunity to take part in clinical trials and to ensure that research is appropriately designed and conducted. Barriers to participation of elderly patients in clinical trials include complex protocols with onerous outcome measures, a research focus on aggressive therapies with substantial toxicity, restrictive entry criteria unnecessarily excluding concurrent conditions and medication, patients' and families' limited expectations of benefits and lack of financial, logistic and social support.Participation is encouraged when attitudes of care staff towards research are positive, altruistic motives are acknowledged, approval of family members is gained and protocols are designed for patient rather than staff convenience. Special consideration should be given to ensuring that patient consent is fully informed and freely given. Elderly patients may have more difficulty comprehending consent information and particular attention should be given to compensating for communication and sensory deficits, improving readability of information sheets and consent forms, and considering the use of innovative consent procedures. Those with cognitive impairment and the institutionalised are vulnerable to exploitation and require special consideration and management.

Informed consent for medical research by the elderly

Much has been written about the possible lack of capacity of the elderly, especially certain vulnerable populations of older individuals, to give informed consent for medical research. Several small studies have shown a deficit for comprehension of consent material, by the elderly, especially those with less education, but this appears small in comparison to an overall deficit in the general population. A number of investigations have suggested that deficits in executive control functions (ECFs) may be related to lack of capacity to make clinical judgments, but these have yet to be applied to research. Many methods have been piloted to measure capacity and to improve comprehension, some of which may help, although none has been proved conclusively to do either. As the elderly experience significant morbidity and mortality from a vast array of illnesses, the use of the elderly as subjects of medical research is especially important. To prevent older individuals from being coerced into participating or potentially being harmed by scientific investigation, they must give informed consent to their involvement. However, there are many studies to suggest that they are not well informed. A discussion ensued in the 1970s and 1980s about whether or not the elderly deserved special protection as a class of individuals, based on their possible increased risk during medical experimentation, but it was ultimately decided that, because the majority of elderly are perceived to be cognitively intact, they need not receive additional safeguards (High & Doole, 1995, Behavioral Science and Law, 13, 319-335). The U.S. Department of Health and Human Services in 2000 (Federal Registrar Rules and Regulations, 46, 8366-8392) reviewed existing protections for subjects of human research and deemed they were inadequate, issuing new guidelines. This article reviews evidence that differences exist between the ability of young and old in their capacity to give consent. Alterations in methods of obtaining consent may help individuals to give a more informed consent, and even enable subjects who lack the capacity to consent, such as cognitively impaired individuals, to participate in research. However an ideal means of screening or altering the consent process has yet to be devised. Many of these methods are briefly considered.

Providing information to help Medicare beneficiaries choose a health plan

Many Medicare beneficiaries have limited knowledge of the Medicare program and related health insurance options. This is due in part to the complexity of the Medicare program and supplemental health insurance market. A recent congressional mandate through the Balanced Budget Act of 1997 called for broad dissemination of information to educate beneficiaries about their health plan options and to encourage informed health plan decision-making. In response, the Health Care Financing Administration (HCFA) launched the National Medicare Education Program (NMEP) to support the educational objectives of the BBA. This paper provides an overview of the components of the NMEP information campaign. We also review lessons learned from our experience in designing and testing a prototype consumer handbook that explains the different health plan options to Medicare beneficiaries. Through our discussion of the handbook, we highlight several ways to communicate information effectively about a complex publicly funded program to an older adult population.

Applying cognitive design principles to formatting HRQOL instruments

Researchers developing or using health-related quality of life (HRQOL) instruments can benefit from knowledge of state-of-the-art formatting methods for self-administered questionnaires. Three objectives in formatting design are: (1) to reduce errors in respondent navigation through the questionnaire that lead to item non-response and question misinterpretation; (2) to reduce respondent and administrative burden; and (3) to enhance respondent motivation in question answering and compliance with the request to participate. Based on an extensive literature review to identify techniques that have been shown to meet these objectives, we developed specific guidelines for HRQOL instruments concerning all aspects of questionnaire formatting. These guidelines represent well-motivated recommendations for improving HRQOL instruments, although their overall impact has not been empirically tested. We applied the guidelines to several HRQOL instruments that are widely used internationally, and obtained approval from the developers for all formatting changes to their instruments. Applying cognitive design principles and empirically substantiated formatting techniques produces an HRQOL instrument formatting with six critical attributes: simple, consistent, organized, natural, clear and attractive. The present paper contributes to the emerging research literature on the cognitive processes by which respondents answer HRQOL questions and demonstrates how 'cognitive aspects of survey methodology' research can improve HRQOL data collection efforts.

Improving understanding of the informed consent process and document

OBJECTIVES

To review theoretical perspectives relating to the communication of informed consent and to describe research efforts and strategies to enhance the informed consent process and document.

DATA SOURCES

Research studies review articles, education and communication models, and NCI National Working Group on Informed Consent Recommendations.

CONCLUSIONS

Information communicated during the informed consent process is difficult to understand, raising ethical concerns about whether informed decision-making has taken place. Empirical research focuses on the nature of patient-provider interactions and the effectiveness of various delivery systems, a need exists to overcome conceptual and methodologic limitations.

IMPLICATIONS FOR NURSING PRACTICE

Nurses must ensure that patients understand informed consent information. Several communication strategies are posited.

Getting meaningful informed consent from older adults: a structured literature review of empirical research

OBJECTIVES

To perform a structured literature review of the published empirical research on informed consent with older adults in order to make recommendations to improve the informed consent process and to highlight areas needing further examination.

DESIGN

Relevant literature was identified by searching electronic databases (AGELINE, BIOETHICSLINE, CancerLit, Ethics Index, Health, LegalTrac, MEDLINE, PAIS International, PsycInfo, and Sociofile). Studies were included if they were reports of primary research data about informed consent and, if patients or other subjects were used, older subjects were included in the sample. Data related to the aspect of informed consent under study (recruitment, decision-making capacity, voluntariness, disclosure of information, understanding of information, consent forms, authorization, and policies and procedures) were abstracted and entered into a specially designed database.

MEASUREMENTS

Characterization of the population, age of subjects, setting, whether informed consent was being studied in the context of research or treatment, study design, the nature of outcome or dependent variables, independent variables (e.g., experimental conditions in a randomized controlled trial or patient/subject characteristics in a nonrandomized comparison), and results according to the aspect of informed consent under study.

RESULTS

A total of 99 articles met all the inclusion criteria and posed 289 unique research questions covering a wide range of aspects of informed consent: recruitment (60); decision making capacity (21); voluntariness (6); disclosure (30); understanding (139); consent forms (7); authorization (11); policies (13); and other (2). In the secondary analyses of numerous studies, diminished understanding of informed consent information was associated with older age and fewer years of education. Older age was also sometimes associated with decreased participation in research. Studies of disclosure of informed consent information suggest strategies to improve understanding and include a variety of novel formats (e.g., simplified, storybook, video) and procedures (e.g., use of health educators, quizzing subjects, multiple disclosure sessions).

CONCLUSIONS

A systematic review of the published literature on informed consent reveals evidence for impaired understanding of informed consent information in older subjects and those with less formal education. Effective strategies to improve the understanding of informed consent information should be considered when designing materials, forms, policies, and procedures for obtaining informed consent. Other than empirical research that has investigated disclosure and understanding of informed consent information, little systematic research has examined other aspects of the informed consent process. This deficit should be rectified to ensure that the rights and interests of patients and of human subjects who participate in research are adequately protected.

Shared understandings for informed consent: the relevance of psychological research on the provision of information

The achievement of informed consent from patients and potential research participants is considered a basic requirement in clinical care and clinical research, but ethicists have paid little attention to the psychological processes and social factors involved in sharing information between individuals. Although many studies on consent have provided useful results, they are rarely informed by basic research in the social sciences. As a result, there are a large number of methodological and conceptual issues which have not been adequately addressed. The purpose of this paper is to illustrate how the work of cognitive and social psychologists can provide insights that are both relevant and valuable to the process of attaining consent. Research in these areas within psychology has indicated that there are important individual differences in how much information people require and that patients' current state of mind can affect estimates of probability, thus making analogue studies misleading. Collaboration between psychologists and ethicists would be of great value in identifying likely areas of mutual interest, particularly the choice of language in consent forms and information sheets, the design of consent forms, the amount of information provided, and the specification of risks and benefits.

Obtaining "informed" consent from the elderly

Regardless of the age of the potential subjects, three conditions constitute informed consent: freedom to decide, clear information, and decision-making capacity. Numerous factors associated with the aging process affect elders' abilities to fulfill all of these conditions; however, as research involving the elderly increases, researchers must act responsibly to ensure that the rights and privileges of elderly research subjects are protected. There are numerous techniques researchers can use to increase the likelihood that truly informed consent is being obtained from elderly potential subjects; this article has described a few of these techniques. Many of the techniques mentioned require additional investigator time. Extra time to ensure this is a small price to pay for setting the stage for greater cooperation and increased quality of research. The development and dissemination of informed consent process guidelines geared toward the needs of the elderly would facilitate an individual researcher's efforts to protect elderly subjects.