Randomized consent designs in randomized controlled trials: Systematic literature search

[International Multi-stakeholder Consensus Statement on Clinical Trial Integrity]

BACKGROUND

Science integrity initiatives require specific recommendations for randomised clinical trials (RCT).

OBJECTIVE

To prepare a set of statements for RCT integrity through an international multi-stakeholder consensus.

METHODS

The consensus was developed via multi-country multidisciplinary stakeholder group composition and engagement; evidence synthesis of 55 systematic reviews concerning RCT integrity; anonymised two-round modified Delphi survey with consensus threshold based on the average percent of majority opinions; and, a final consensus development meeting.

RESULTS

There were 30 stakeholders representing 15 countries from 5 continents including trialists, ethicists, methodologists, statisticians, consumer representative, industry representative, systematic reviewers, funding body panel members, regulatory experts, authors, journal editors, peer-reviewers and advisors for resolving integrity concerns. Delphi survey response rate was 86.7% (26/30 stakeholders). There were 111 statements (73 stakeholder-provided, 46 systematic review-generated, 8 supported by both) in the initial long list, with 8 additional statements provided during the consensus rounds. Through consensus the final set consolidated 81 statements (49 stakeholder-provided, 41 systematic review-generated, 9 supported by both). The entire RCT life cycle was covered by the set of statements including general aspects (n=6), design and approval (n=11), conduct and monitoring (n=19), reporting of protocols and findings (n=20), post-publication concerns (n=12), and future research and development (n=13).

CONCLUSION

Implementation of this multi-stakeholder consensus statement is expected to enhance RCT integrity.

Research integrity in randomized clinical trials: A scoping umbrella review

BACKGROUND

Randomized clinical trials (RCTs) are experiencing a crisis of confidence in their trustworthiness. Although a comprehensive literature search yielded several reviews on RCT integrity, an overarching overview is lacking.

OBJECTIVES

The authors undertook a scoping umbrella review of the research integrity literature concerning RCTs.

SEARCH STRATEGY AND SELECTION CRITERIA

Following prospective registration (https://osf.io/3ursn), two reviewers independently searched PubMed, Scopus, The Cochrane Library, and Google Scholar, without language or time restrictions, until November 2021. The authors included systematic reviews covering any aspect of research integrity throughout the RCT lifecycle.

DATA COLLECTION AND ANALYSIS

The authors assessed methodological quality using a modified AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews) tool and collated the main findings.

MAIN RESULTS

A total of 55 relevant reviews, summarizing 6001 studies (median per review, 63; range, 8-1106) from 1964 to 2021, had an overall critically low quality of 96% (53 reviews). Topics covered included general aspects (15%), design and approval (22%), conduct and monitoring (11%), reporting (38%), postpublication concerns (2%), and future research (13%). The most common integrity issues covered were ethics (18%) and transparency (18%).

CONCLUSIONS

Low-quality reviews identified various integrity issues across the RCT lifecycle, emphasizing the importance of high ethical standards and professionalism while highlighting gaps in the integrity landscape. Multistakeholder consensus is needed to develop specific RCT integrity standards.

Assessing the Integrity of Clinical Trials Included in Evidence Syntheses

Evidence syntheses of randomized clinical trials (RCTs) offer the highest level of scientific evidence for informing clinical practice and policy. The value of evidence synthesis itself depends on the trustworthiness of the included RCTs. The rising number of retractions and expressions of concern about the authenticity of RCTs has raised awareness about the existence of problematic studies, sometimes called "zombie" trials. Research integrity, i.e., adherence to ethical and professional standards, is a multi-dimensional concept that is incompletely evaluated for the RCTs included in current evidence syntheses. Systematic reviewers tend to rely on the editorial and peer-review system established by journals as custodians of integrity of the RCTs they synthesize. It is now well established that falsified and fabricated RCTs are slipping through. Thus, RCT integrity assessment becomes a necessary step in systematic reviews going forward, in particular because RCTs with data-related integrity concerns remain available for use in evidence syntheses. There is a need for validated tools for systematic reviewers to proactively deploy in the assessment of integrity deviations without having to wait for RCTs to be retracted by journals or expressions of concern issued. This article analyzes the issues and challenges in conducting evidence syntheses where the literature contains RCTs with possible integrity deficits. The way forward in the form of formal RCT integrity assessments in systematic reviews is proposed, and implications of this new initiative are discussed. Future directions include emphasizing ethical and professional standards, providing tailored integrity-specific training, and creating systems to promote research integrity, as improvements in RCT integrity will benefit evidence syntheses.

International multi-stakeholder consensus statement on clinical trial integrity

OBJECTIVE

To prepare a set of statements for randomised clinical trials (RCT) integrity through an international multi-stakeholder consensus.

METHODS

The consensus was developed via: multi-country multidisciplinary stakeholder group composition and engagement; evidence synthesis of 55 systematic reviews concerning RCT integrity; anonymised two-round modified Delphi survey with consensus threshold based on the average percentage of majority opinions; and, a final consensus development meeting. Prospective registrations: (https://osf.io/bhncy, https://osf.io/3ursn).

RESULTS

There were 30 stakeholders representing 15 countries from five continents including triallists, ethicists, methodologists, statisticians, consumer representatives, industry representatives, systematic reviewers, funding body panel members, regulatory experts, authors, journal editors, peer-reviewers and advisors for resolving integrity concerns. Delphi survey response rate was 86.7% (26/30 stakeholders). There were 111 statements (73 stakeholder-provided, 46 systematic review-generated, 8 supported by both) in the initial long list, with eight additional statements provided during the consensus rounds. Through consensus the final set consolidated 81 statements (49 stakeholder-provided, 41 systematic review-generated, 9 supported by both). The entire RCT life cycle was covered by the set of statements including general aspects (n = 6), design and approval (n = 11), conduct and monitoring (n = 19), reporting of protocols and findings (n = 20), post-publication concerns (n = 12), and future research and development (n = 13).

CONCLUSION

Implementation of this multi-stakeholder consensus statement is expected to enhance RCT integrity.

Taking a chance: How likely am I to receive my preferred treatment in a clinical trial?

Researchers should ideally conduct clinical trials under a presumption of clinical equipoise, but in fact trial patients will often prefer one or other of the treatments being compared. Receiving an unblinded preferred treatment may affect the study outcome, possibly beneficially, but receiving a non-preferred treatment may induce 'reluctant acquiescence', and poorer outcomes. Even in blinded trials, patients' primary motivation to enrol may be the chance of potentially receiving a desirable experimental treatment, which is otherwise unavailable. Study designs with a higher probability of receiving a preferred treatment (denoted as 'concordance') will be attractive to potential participants, and investigators, because they may improve recruitment and hence enhance study efficiency. Therefore, it is useful to consider the concordance rates associated with various study designs. We consider this question with a focus on comparing the standard, randomised, two-arm, parallel group design with the two-stage randomised patient preference design and Zelen designs; we also mention the fully randomised and partially randomised patient preference designs. For each of these designs, we evaluate the concordance rate as a function of the proportions randomised to the alternative treatments, the distribution of preferences over treatments, and (for the Zelen designs) the proportion of patients who consent to receive their assigned treatment. We also examine the equity of each design, which we define as the similarity between the concordance rates for participants with different treatment preferences. Finally, we contrast each of the alternative designs with the standard design in terms of gain in concordance and change in equity.

E-health psychological intervention in pregnant women exposed to intimate partner violence (eIPV): A protocol for a pilot randomised controlled trial

Intimate partner violence (IPV) during pregnancy, a condition as common as obstetrics conditions like gestational diabetes, is associated with maternal and neonatal complications. Systematic detection of IPV is not well established in antenatal screening probably because the effectiveness of protective interventions has not been evaluated. E-health interventions may be beneficial among mothers exposed to IPV. Prior to performing a full-scale effectiveness trial for such an intervention, a pilot study is required to assess the feasibility of randomising a sufficiently large number of women exposed to IPV during pregnancy. The eIPV trial is a randomised pilot study nested within a cohort of consenting mothers who screen positive for IPV in the first antenatal visit at <12 weeks' gestation and accept an e-health package (psychological counselling by videoconference) in Spain and Denmark. Twenty eligible mothers from the above cohort will be randomised to either intervention or control. The intervention group will receive the e-health package as part of the cohort. The control group will be invited to accept a delay in the intervention (e-health package eight weeks later). After consenting to delay, the control group will provide comparative data without losing the opportunity of obtaining the intervention. We will determine estimates of rates of informed consent to randomization, and the rates of adherence and dropout following randomization. Qualitative interviews will be conducted to examine the women's perception about the benefit of the intervention, reasons for acceptability and non-adherence, and obstacles to recruitment, randomisation and consent. The results will inform the trial feasibility and variance of key clinical outcome measures for estimation of sample size of the full-scale effectiveness trial.

The adapted Zelen was a feasible design to trial exercise in myeloma survivors

OBJECTIVES

We used a method rarely seen in cancer behavioral trials to explore methods of overcoming difficulties often seen in randomized controlled trials. We report our experiences of the adapted Zelen design, so that other researchers can consider this approach for behavioral trials.

STUDY DESIGN AND SETTING

The adapted Zelen design was used to explore the effects of exercise on multiple myeloma patients fatigue, quality of life, and physical outcomes. All participants consented to an observational cohort study of lifestyle factors but were unaware of subsequent randomization to remain in cohort only group or be offered an exercise intervention requiring second consent.

RESULTS

There was lower than expected uptake to the exercise offered group (57%), so the length of recruitment increased from 24 to 29 months to ensure power was reached. At enrollment, patients were unaware of the potential increased commitment, and as a result, 62% of participants allocated to the intervention declined because of the extra time/travel commitment required. This emulates clinical settings and suggests improvements in intervention delivery are required. Our findings suggest that the adapted Zelen design may be useful in limiting dropout of controls due to dissatisfaction from group allocation, or contamination of control arm.

CONCLUSION

Future use of this design warrants careful consideration of the study resources and recruitment time frames required but holds potential value in reducing contamination, control group dissatisfaction, and resulting dropout. Adapted Zelen design reduces selection bias and therefore gives clinicians a better understanding of acceptability in clinical settings. Future studies should evaluate control group experiences of the design and formally record contamination throughout the study to confirm its acceptability.

Combating HIV stigma in low- and middle-income healthcare settings: a scoping review

INTRODUCTION

Nearly 40 years into the HIV epidemic, the persistence of HIV stigma is a matter of grave urgency. Discrimination (i.e. enacted stigma) in healthcare settings is particularly problematic as it deprives people of critical healthcare services while also discouraging preventive care seeking by confirming fears of anticipated stigma. We review existing research on the effectiveness of stigma interventions in healthcare settings of low- and middle-income countries (LMIC), where stigma control efforts are often further complicated by heavy HIV burdens, less developed healthcare systems, and the layering of HIV stigma with discrimination towards other marginalized identities. This review describes progress in this field to date and identifies research gaps to guide future directions for research.

METHODS

We conducted a scoping review of HIV reduction interventions in LMIC healthcare settings using Embase, Ovid MEDLINE, PsycINFO and Scopus (through March 5, 2020). Information regarding study design, stigma measurement techniques, intervention features and study findings were extracted. We also assessed methodological rigor using the Joanna Briggs Institute checklist for systematic reviews.

RESULTS AND DISCUSSION

Our search identified 8766 studies, of which 19 were included in the final analysis. All but one study reported reductions in stigma following the intervention. The studies demonstrated broad regional distribution across LMIC and many employed designs that made use of a control condition. However, these strengths masked key shortcomings including a dearth of research from the lowest income category of LMIC and a lack of interventions to address institutional or structural determinants of stigma. Lastly, despite the fact that most stigma measures were based on existing instruments, only three studies described steps taken to validate or adapt the stigma measures to local settings.

CONCLUSIONS

Combating healthcare stigma in LMIC demands interventions that can simultaneously address resource constraints, high HIV burden and more severe stigma. Our findings suggest that this will require more objective, reliable and culturally adaptable stigma measures to facilitate meaningful programme evaluation and comparison across studies. All but one study concluded that their interventions were effective in reducing healthcare stigma. Though encouraging, the fact that most studies measured impact using self-reported measures suggests that social desirability may bias results upwards. Homogeneity of study results also hindered our ability to draw substantive conclusions about potential best practices to guide the design of future stigma reduction programmes.

Dexamethasone for Cardiac Surgery trial (DECS-II): Rationale and a novel, practice preference-randomized consent design

BACKGROUND

Numerous studies have investigated high-dose corticosteroids in cardiac surgery, but with mixed results leading to ongoing variations in practice around the world. DECS-II is a study comparing high-dose dexamethasone with placebo in patients undergoing cardiac surgery.

METHODS

We discuss the rationale for conducting DECS-II, a 2800-patient, pragmatic, multicenter, assessor-blinded, randomized trial in cardiac surgery, and the features of the DECS-II study design (objectives, end points, target population, based on practice preference with post-randomization consent, treatments, patient follow-up and analysis).

CONCLUSIONS

The DECS-II trial will use a novel, efficient trial design to evaluate whether high-dose dexamethasone has a patient-centered benefit of enhancing recovery and increasing the number of days at home after cardiac surgery.

Ethics and practice of Trials within Cohorts: An emerging pragmatic trial design

BACKGROUND

With increasing emphasis on pragmatic trials, new randomized clinical trial designs are being proposed to enhance the "real world" nature of the data generated. We describe one such design, appropriate for unmasked pragmatic clinical trials in which the control arm receives usual care, called "Trials within Cohorts" that is increasingly used in various countries because of its efficiency in recruitment, advantages in reducing subject burden, and ability to better mimic real-world consent processes.

METHODS

Descriptive, ethical, and US regulatory analysis of the Trials within Cohorts design.

RESULTS

Trials within Cohorts design involves, after recruitment into a cohort, randomization of eligible subjects, followed by an asymmetric treatment of the two arms: those selected for the experimental arm provide informed consent for the intervention trial, while the data from the control arm are used based on prior broad permission. Thus, unlike the traditional Zelen post-randomization consent design, the cohort participants are informed about future research within the cohort; however, the extent of this disclosure currently varies among studies. Thus, ethical analysis is provided for two types of situations: when the pre-randomization disclosure and consent regarding the embedded trials are fairly explicit and detailed versus when they consist of only general statements about future data use. These differing ethical situations could have implications for how ethics review committees apply US research rules regarding waivers and alterations of informed consent.

CONCLUSION

Trials within Cohorts is a promising new pragmatic randomized controlled trial design that is being increasingly used in various countries. Although the asymmetric consent procedures for the experimental versus control arm subjects can initially raise ethical concerns, it is ethically superior to previous post-randomization consent designs and can have important advantages over traditional trial designs.

Proposals to Conduct Randomized Controlled Trials Without Informed Consent: a Narrative Review

BACKGROUND

Individual informed consent from all participants is required for most randomized clinical trials (RCTs). However, some exceptions-for example, emergency research-are widely accepted.

METHODS

The literature on various approaches to randomization without consent (RWOC) has never been systematically reviewed. Our goal was to provide a survey and narrative synthesis of published proposals for RWOC. We focused on proposals to randomize at least some participants in a study without first obtaining consent to randomization. This definition included studies that omitted informed consent entirely, omitted informed consent for selected patients (e.g., the control group), obtained informed consent to research but not to randomization, or only obtained informed consent to randomization after random assignment had already occurred. It omitted oral and staged consent processes that still obtain consent to randomization from all participants before randomization occurs.

RESULTS

We identified ten different proposals for RWOC: two variants of cluster randomization, two variants of the Zelen design, consent to postponed information, two-stage randomized consent, cohort multiple RCT, emergency research, prompted optional randomization trials, and low-risk pragmatic RCTs without consent.

CONCLUSION

Of all designs discussed here, only cluster randomized designs and emergency research are routinely used, with the justification that informed consent is infeasible in those settings. Other designs have raised concerns that they do not appropriately respect patient autonomy. Recent proposals have emphasized the importance for RWOC of demonstrating such respect through systematic patient engagement, transparency, and accountability, potentially in the context of learning health care systems.

Exceptions to the rule of informed consent for research with an intervention

BACKGROUND

In specific situations it may be necessary to make an exception to the general rule of informed consent for scientific research with an intervention. Earlier reviews only described subsets of arguments for exceptions to waive consent.

METHODS

Here, we provide a more extensive literature review of possible exceptions to the rule of informed consent and the accompanying arguments based on literature from 1997 onwards, using both Pubmed and PsycINFO in our search strategy.

RESULTS

We identified three main categories of arguments for the acceptability of a consent waiver: data validity and quality, major practical problems, and distress or confusion of participants. Approval by a medical ethical review board always needs to be obtained. Further, we provide examples of specific conditions under which consent waiving might be allowed, such as additional privacy protection measures.

CONCLUSIONS

The reasons legitimized by the authors of the papers in this overview can be used by researchers to form their own opinion about requesting an exception to the rule of informed consent for their own study. Importantly, rules and guidelines applicable in their country, institute and research field should be followed. Moreover, researchers should also take the conditions under which they feel an exception is legitimized under consideration. After discussions with relevant stakeholders, a formal request should be sent to an IRB.

A pilot 'cohort multiple randomised controlled trial' of treatment by a homeopath for women with menopausal hot flushes

INTRODUCTION

In order to address the limitations of the standard pragmatic RCT design, the innovative 'cohort multiple RCT' design was developed. The design was first piloted by addressing a clinical question " What is the clinical and cost effectiveness of treatment by a homeopath for women with menopausal hot flushes?".

METHODS

A cohort with the condition of interest (hot flushes) was recruited through an observational study of women's midlife health and consented to provide observational data and have their data used comparatively. The 'Hot Flush' Cohort were then screened in order to identify patients eligible for a trial of the offer of treatment by a homeopath (Eligible Trial Group). A proportion of the Eligible Trial Group was then randomly selected to the Offer Group and offered treatment. A "patient centred" approach to information and consent was adopted. Patients were not (i) told about treatments that they would not be offered, and trial intervention information was only given to the Offer Group after random selection. Patients were not (ii) given prior information that their treatment would be decided by chance.

RESULTS

The 'cohort multiple RCT' design was acceptable to the NHS Research Ethics Committee. The majority of patients completed multiple questionnaires. Acceptance of the offer was high (17/24).

DISCUSSION

This pilot identified the feasibility of an innovative design in practice. Further research is required to test the concept of undertaking multiple trials within a cohort of patients and to assess the acceptability of the "patient centred" approach to information and consent.

The impact of a population-based multi-factorial lifestyle intervention on alcohol intake: the Inter99 study

PURPOSE

To investigate the effect of screening and five years of multi-factorial lifestyle intervention on changes in alcohol intake in a general population.

METHODS

The study was a pre-randomized intervention study on lifestyle, Inter99 (1999-2006), Copenhagen, Denmark. Participants in the intervention group (n=6 091) had at baseline a medical health examination and a face-to-face lifestyle counselling. Individuals at high risk of ischemic heart disease were repeatedly offered both individual and group-based counselling. The control group (n=3 324) was followed by questionnaires. Alcohol intake was measured by questionnaires. Changes were analysed by multilevel analyses.

RESULTS

Binge drinking decreased both in men and women at three and five-year follow-ups (men: five-year: net-change:-0.13; p=0.03; women: five-year: net-change:-0.08; p=0.04). Furthermore, in women the ratio between wine and total alcohol was increased compared with the control group at five-year follow-up (net-change: 0.04; p<0.01). In men with a high intake of alcohol (>21 drinks per week) the effect on total alcohol intake was maintained at five-year follow-up (net-change: -3.7; p=0.01). No significant effects were found in women on total alcohol intake.

CONCLUSION

Multi-factorial lifestyle intervention, including low intensity alcohol intervention, improved long-term alcohol habits in a general population.

Indications and requirements for the use of prerandomization

BACKGROUND AND OBJECTIVE

Although in effectiveness studies, the conventional randomized trial, in which informed consent is obtained before randomization, is the first choice, this design is not the panacea for all research questions. To counter contamination problems, prerandomization designs might be an alternative. Prerandomization implies that the randomization takes place before seeking informed consent, and because of this, prerandomization designs are controversial among ethicists, health lawyers, methodologists, and clinicians. However, in the Netherlands, these designs are becoming more accepted since the Dutch State Secretary of Health, Welfare and Sport decided that, under certain circumstances, prerandomization is admissible and not in conflict with the law.

RESULTS

Based on well-defined indications and requirements, guidelines for the optimal application of prerandomization designs are presented. Designs in which prerandomization is used are outlined; methodological considerations useful when conducting trials using conventional designs or prerandomization designs are discussed, in addition to ethical and judicial aspects.

CONCLUSION

In certain situations, prerandomization designs have an essential contribution to achieve evidence-based medicine. Banning prerandomization a priori implies that information about the effectiveness of numerous public health and medical interventions will not be forthcoming. Therefore, every design should be based on a balance between maximizing the potential for patient autonomy and minimizing the bias caused by contamination. This balance cannot be reached by formulating general rules, but an independent group of experts, like members of research ethics committee (REC), should decide whether this balance is acceptable.

The impact of a population-based multi-factorial lifestyle intervention on changes in long-term dietary habits: the Inter99 study

OBJECTIVE

To evaluate the effectiveness of a population-based multi-factorial lifestyle intervention on long-term changes in dietary habits compared to a non-intervention control group.

METHODS

The study was a randomized controlled lifestyle intervention study, Inter99 (1999-2006), Copenhagen, Denmark, using a high-risk strategy. Participants in the intervention group (n=6 091) had at baseline a medical health-examination and a face-to-face lifestyle counselling. Individuals at high risk of ischemic heart disease were repeatedly offered both individual and group-based counselling. The control group (n=3 324) was followed by questionnaires. Dietary habits were measured by a validated 48-item food frequency questionnaire and changes were analyzed by multilevel analyses.

RESULTS

At the 5-year follow-up the intervention group compared to the control group had significantly increased their intake of vegetables (men: net-change: 23 g/week; p=0.04; women: net-change: 27 g/week; p=0.005) and decreased the intake of highly saturated fats used on bread and for cooking (men: OR=0.59 (0.41-0.86); women: OR=0.42 (0.30-0.59)). Significant effects on fruit and fish intake were found at the 3-year follow-up but the effect attenuated at the 5-year follow-up.

CONCLUSION

A population-based multi-factorial lifestyle intervention promoted significant greater beneficial long-term dietary changes compared to the control group, especially the intake of vegetables and saturated fat was improved.