Using the Zelen design in randomized controlled trials: debates and controversies

When does the placebo effect have an impact on network meta-analysis results?

The placebo effect is the 'effect of the simulation of treatment that occurs due to a participant's belief or expectation that a treatment is effective'. Although the effect might be of little importance for some conditions, it can have a great role in others, mostly when the evaluated symptoms are subjective. Several characteristics that include informed consent, number of arms in a study, the occurrence of adverse events and quality of blinding may influence response to placebo and possibly bias the results of randomised controlled trials. Such a bias is inherited in systematic reviews of evidence and their quantitative components, pairwise meta-analysis (when two treatments are compared) and network meta-analysis (when more than two treatments are compared). In this paper, we aim to provide red flags as to when a placebo effect is likely to bias pairwise and network meta-analysis treatment effects. The classic paradigm has been that placebo-controlled randomised trials are focused on estimating the treatment effect. However, the magnitude of placebo effect itself may also in some instances be of interest and has also lately received attention. We use component network meta-analysis to estimate placebo effects. We apply these methods to a published network meta-analysis, examining the relative effectiveness of four psychotherapies and four control treatments for depression in 123 studies.

Efficacy and safety comparison of infrared laser moxibustion and traditional moxibustion in knee osteoarthritis: study protocol for a Zelen-design randomized controlled non-inferiority clinical trial

BACKGROUND

Knee osteoarthritis (KOA) is the most common chronic degenerative joint disease and places a substantial burden on the public health resources in China. The purpose of this study is to preliminarily evaluate whether infrared laser moxibustion (ILM) is non-inferior to traditional moxibustion (TM) in the treatment of KOA.

MATERIALS AND METHODS

In the designed Zelen-design randomized controlled non-inferiority clinical trial, a total of 74 patients with KOA will be randomly allocated to one of two interventions: ILM treatment or TM treatment. All participants will receive a 6-week treatment and a follow-up 4 weeks after treatment. The primary outcomes will be the mean change in pain scores on the numeric rating scale (NRS) measured at baseline and the end of last treatment at week 6. The secondary outcomes will be the pain scores on the NRS from weeks 1 to 5 after the start of treatment and the changes from baseline to endpoints (weeks 6 and 10) in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), SF-36, knee circumference, and 6-min walking test. In addition, safety assessment will be performed throughout the trial.

CONCLUSION

The results of our study will help determine whether a 6-week treatment with ILM is non-inferior to TM in patients with KOA, therefore providing evidence to verify if ILM can become a safer alternative for TM in clinical applications in the future.

TRIAL REGISTRATION

Clinical Trial Registration Platform (ChiCTR2200065264); Pre-results. Registered on 1 November 2022.

An Incognito Standardized Patient Approach for Measuring and Reducing Intersectional Healthcare Stigma

Background

Consistent evidence highlights the role of stigma in impairing healthcare access in people living with HIV (PLWH), men who have sex with men (MSM), and people with both identities. We developed an incognito standardized patient (SP) approach to obtain observations of providers to inform a tailored, relevant, and culturally appropriate stigma reduction training. Our pilot cluster randomized control trial assessed the feasibility, acceptability, and preliminary effects of an intervention to reduce HIV stigma, anti-gay stigma, and intersectional stigma.

Methods

Design of the intervention was informed by the results of a baseline round of incognito visits in which SPs presented standardized cases to consenting doctors. The HIV status and sexual orientation of each case was randomly varied, and stigma was quantified as differences in care across scenarios. Care quality was measured in terms of diagnostic testing, diagnostic effort, and patient-centered care. Impact of the training, which consisted of didactic, experiential, and discussion-based modules, was assessed by analyzing results of a follow-up round of SP visits using linear fixed effects regression models.

Results

Feasibility and acceptability among the 55 provider participants was high. We had a 87.3% recruitment rate and 74.5% completion rate of planned visits (N=238) with no adverse events. Every participant found the training content "highly useful" or "useful." Preliminary effects suggest that, relative to the referent case (HIV negative straight man), the intervention positively impacted testing for HIV negative MSM (0.05 percentage points [PP], 95% CI,-0.24, 0.33) and diagnostic effort in HIV positive MSM (0.23 standard deviation [SD] improvement, 95% CI, -0.92, 1.37). Patient-centered care only improved for HIV positive straight cases post-training relative to the referent group (SD, 0.57; 95% CI, -0.39, 1.53). All estimates lacked statistical precision, an expected outcome of a pilot RCT.

Conclusions

Our pilot RCT demonstrated high feasibility, acceptability, and several areas of impact for an intervention to reduce enacted healthcare stigma in a low-/middle-income country setting. The relatively lower impact of our intervention on care outcomes for PLWH suggests that future trainings should include more clinical content to boost provider confidence in the safe and respectful management of patients with HIV.

Research objectives and general considerations for pragmatic clinical trials of pain treatments: IMMPACT statement

ABSTRACT

Many questions regarding the clinical management of people experiencing pain and related health policy decision-making may best be answered by pragmatic controlled trials. To generate clinically relevant and widely applicable findings, such trials aim to reproduce elements of routine clinical care or are embedded within clinical workflows. In contrast with traditional efficacy trials, pragmatic trials are intended to address a broader set of external validity questions critical for stakeholders (clinicians, healthcare leaders, policymakers, insurers, and patients) in considering the adoption and use of evidence-based treatments in daily clinical care. This article summarizes methodological considerations for pragmatic trials, mainly concerning methods of fundamental importance to the internal validity of trials. The relationship between these methods and common pragmatic trials methods and goals is considered, recognizing that the resulting trial designs are highly dependent on the specific research question under investigation. The basis of this statement was an Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) systematic review of methods and a consensus meeting. The meeting was organized by the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership. The consensus process was informed by expert presentations, panel and consensus discussions, and a preparatory systematic review. In the context of pragmatic trials of pain treatments, we present fundamental considerations for the planning phase of pragmatic trials, including the specification of trial objectives, the selection of adequate designs, and methods to enhance internal validity while maintaining the ability to answer pragmatic research questions.

A randomized controlled trial evaluating combination detection of HIV in Malawian sexually transmitted infections clinics

INTRODUCTION

HIV diagnosis is the necessary first step towards HIV care initiation, yet many persons living with HIV (PLWH) remain undiagnosed. Employing multiple HIV testing strategies in tandem could increase HIV detection and promote linkage to care. We aimed to assess an intervention to improve HIV detection within socio-sexual networks of PLWH in two sexually transmitted infections (STI) clinics in Lilongwe, Malawi.

METHODS

We conducted a randomized controlled trial to evaluate an intervention combining acute HIV infection (AHI) screening, contract partner notification and social contact referral versus the Malawian standard of care: serial rapid serological HIV tests and passive partner referral. Enrolment occurred between 2015 and 2019. HIV-seropositive persons (two positive rapid tests) were randomized to the trial arms and HIV-seronegative (one negative rapid test) and -serodiscordant (one positive test followed by a negative confirmatory test) persons were screened for AHI with HIV RNA testing. Those found to have AHI were offered enrolment into the intervention arm. Our primary outcome of interest was the number of new HIV diagnoses made per index participant within participants' sexual and social networks. We also calculated total persons, sexual partners and PLWH (including those previously diagnosed) referred per index participant.

RESULTS

A total of 1230 HIV-seropositive persons were randomized to the control arm, and 561 to the intervention arm. Another 12,713 HIV-seronegative or -serodiscordant persons underwent AHI screening, resulting in 136 AHI cases, of whom 94 enrolled into the intervention arm. The intervention increased the number of new HIV diagnoses made per index participant versus the control (ratio: 1.9; 95% confidence interval (CI): 1.2 to 3.1). The intervention also increased the numbers of persons (ratio: 2.5; 95% CI: 2.0 to 3.2), sexual partners (ratio: 1.7; 95% CI: 1.4 to 2.0) and PLWH (ratio: 2.3; 95% CI: 1.7 to 3.2) referred per index participant.

CONCLUSIONS

Combining three distinct HIV testing and referral strategies increased the detection of previously undiagnosed HIV infections within the socio-sexual networks of PLWH seeking STI care. Combination HIV detection strategies that leverage AHI screening and socio-sexual contact networks offer a novel and efficacious approach to increasing HIV status awareness.

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.

Resection or radiofrequency ablation for hepatocellular carcinoma? Assessment of validity of current studies, meta-analyses and their influence on guidelines

BACKGROUND

Two Cochrane reviews compared overall survival following liver resection (LR) or radiofrequency ablation (RFA) for patients with hepatocellular carcinoma. The first from 2013, found moderate evidence for a survival advantage for LR over RFA when limiting the analysis to trials at low risk of bias. The second (2017), found no evidence for a difference in all-cause mortality for LR versus RFA. Aim was to assess the validity of the randomized controlled trials included in both Cochrane reviews and to investigate their impact on current guidelines.

METHODS

The validity of the studies was analyzed using the CONSORT checklist. Two meta-analyses were then performed with all eligible studies from both meta-analyses. Finally, the impact of the result of the original meta-analyses on eight international guidelines was assessed.

RESULTS

The four randomized controlled trials showed several inconsistencies (unclear or inadequate randomization, absence of sample-size calculation, missing blinded setup and/or conflicts of interest). All guidelines used recommendations based on the results of the meta-analyses or on studies included in the meta-analyses.

CONCLUSION

The analyzed studies showed a substantial lack of overall validity. However the results of these studies and subsequent meta-analyses are used as the evidence base for the majority of current guidelines.

Rising to the challenge: designing, implementing and reporting exercise oncology trials in understudied populations

Exercise can improve cancer-related fatigue, quality of life and physical fitness, but is understudied in less common cancers such as multiple myeloma. Studying less common cancers and the adoption of novel study designs and open-science practices would improve the generalisability, transparency, rigour, credibility and reproducibility of exercise oncology research.

Decompressive craniectomy for the treatment of high intracranial pressure in closed traumatic brain injury

BACKGROUND

High intracranial pressure (ICP) is the most frequent cause of death and disability after severe traumatic brain injury (TBI). It is usually treated with general maneuvers (normothermia, sedation, etc.) and a set of first-line therapeutic measures (moderate hypocapnia, mannitol, etc.). When these measures fail, second-line therapies are initiated, which include: barbiturates, hyperventilation, moderate hypothermia, or removal of a variable amount of skull bone (secondary decompressive craniectomy).

OBJECTIVES

To assess the effects of secondary decompressive craniectomy (DC) on outcomes of patients with severe TBI in whom conventional medical therapeutic measures have failed to control raised ICP.

SEARCH METHODS

The most recent search was run on 8 December 2019. We searched the Cochrane Injuries Group's Specialised Register, CENTRAL (Cochrane Library), Ovid MEDLINE(R), Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R), Embase Classic + Embase (OvidSP) and ISI Web of Science (SCI-EXPANDED & CPCI-S). We also searched trials registries and contacted experts.

SELECTION CRITERIA

We included randomized studies assessing patients over the age of 12 months with severe TBI who either underwent DC to control ICP refractory to conventional medical treatments or received standard care.

DATA COLLECTION AND ANALYSIS

We selected potentially relevant studies from the search results, and obtained study reports. Two review authors independently extracted data from included studies and assessed risk of bias. We used a random-effects model for meta-analysis. We rated the quality of the evidence according to the GRADE approach.

MAIN RESULTS

We included three trials (590 participants). One single-site trial included 27 children; another multicenter trial (three countries) recruited 155 adults, the third trial was conducted in 24 countries, and recruited 408 adolescents and adults. Each study compared DC combined with standard care (this could include induced barbiturate coma or cooling of the brain, or both). All trials measured outcomes up to six months after injury; one also measured outcomes at 12 and 24 months (the latter data remain unpublished). All trials were at a high risk of bias for the criterion of performance bias, as neither participants nor personnel could be blinded to these interventions. The pediatric trial was at a high risk of selection bias and stopped early; another trial was at risk of bias because of atypical inclusion criteria and a change to the primary outcome after it had started. Mortality: pooled results for three studies provided moderate quality evidence that risk of death at six months was slightly reduced with DC (RR 0.66, 95% CI 0.43 to 1.01; 3 studies, 571 participants; I2 = 38%; moderate-quality evidence), and one study also showed a clear reduction in risk of death at 12 months (RR 0.59, 95% CI 0.45 to 0.76; 1 study, 373 participants; high-quality evidence). Neurological outcome: conscious of controversy around the traditional dichotomization of the Glasgow Outcome Scale (GOS) scale, we chose to present results in three ways, in order to contextualize factors relevant to clinical/patient decision-making. First, we present results of death in combination with vegetative status, versus other outcomes. Two studies reported results at six months for 544 participants. One employed a lower ICP threshold than the other studies, and showed an increase in the risk of death/vegetative state for the DC group. The other study used a more conventional ICP threshold, and results favoured the DC group (15.7% absolute risk reduction (ARR) (95% CI 6% to 25%). The number needed to treat for one beneficial outcome (NNTB) (i.e. to avoid death or vegetative status) was seven. The pooled result for DC compared with standard care showed no clear benefit for either group (RR 0.99, 95% CI 0.46 to 2.13; 2 studies, 544 participants; I2 = 86%; low-quality evidence). One study reported data for this outcome at 12 months, when the risk for death or vegetative state was clearly reduced by DC compared with medical treatment (RR 0.68, 95% CI 0.54 to 0.86; 1 study, 373 participants; high-quality evidence). Second, we assessed the risk of an 'unfavorable outcome' evaluated on a non-traditional dichotomized GOS-Extended scale (GOS-E), that is, grouping the category 'upper severe disability' into the 'good outcome' grouping. Data were available for two studies (n = 571). Pooling indicated little difference between DC and standard care regarding the risk of an unfavorable outcome at six months following injury (RR 1.06, 95% CI 0.69 to 1.63; 544 participants); heterogeneity was high, with an I2 value of 82%. One trial reported data at 12 months and indicated a clear benefit of DC (RR 0.81, 95% CI 0.69 to 0.95; 373 participants). Third, we assessed the risk of an 'unfavorable outcome' using the (traditional) dichotomized GOS/GOS-E cutoff into 'favorable' versus 'unfavorable' results. There was little difference between DC and standard care at six months (RR 1.00, 95% CI 0.71 to 1.40; 3 studies, 571 participants; low-quality evidence), and heterogeneity was high (I2 = 78%). At 12 months one trial suggested a similar finding (RR 0.95, 95% CI 0.83 to 1.09; 1 study, 373 participants; high-quality evidence). With regard to ICP reduction, pooled results for two studies provided moderate quality evidence that DC was superior to standard care for reducing ICP within 48 hours (MD -4.66 mmHg, 95% CI -6.86 to -2.45; 2 studies, 182 participants; I2 = 0%). Data from the third study were consistent with these, but could not be pooled. Data on adverse events are difficult to interpret, as mortality and complications are high, and it can be difficult to distinguish between treatment-related adverse events and the natural evolution of the condition. In general, there was low-quality evidence that surgical patients experienced a higher risk of adverse events.

AUTHORS' CONCLUSIONS

Decompressive craniectomy holds promise of reduced mortality, but the effects of long-term neurological outcome remain controversial, and involve an examination of the priorities of participants and their families. Future research should focus on identifying clinical and neuroimaging characteristics to identify those patients who would survive with an acceptable quality of life; the best timing for DC; the most appropriate surgical techniques; and whether some synergistic treatments used with DC might improve patient outcomes.

Feasibility and long-term efficacy of a proactive health program in the treatment of chronic back pain: a randomized controlled trial

BACKGROUND

To facilitate access to evidence-based care for back pain, a German private medical insurance offered a health program proactively to their members. Feasibility and long-term efficacy of this approach were evaluated.

METHODS

Using Zelen's design, adult members of the health insurance with chronic back pain according to billing data were randomized to the intervention (IG) or the control group (CG). Participants allocated to the IG were invited to participate in the comprehensive health program comprising medical exercise therapy and life style coaching, and those allocated to the CG to a longitudinal back pain survey. Primary outcomes were back pain severity (Korff's Chronic Pain Grade Questionnaire) as well as health-related quality of life (SF-12) assessed by identical online questionnaires at baseline and 2-year follow-up in both study arms. In addition to analyses of covariance, a subgroup analysis explored the heterogeneity of treatment effects among different risks of back pain chronification (STarT Back Tool).

RESULTS

Out of 3462 persons selected, randomized and thereafter contacted, 552 agreed to participate. At the 24-month follow-up, data on 189 of 258 (73.3%) of the IG were available, in the CG on 255 of 294 (86.7%). Significant, small beneficial effects were seen in primary outcomes: Compared to the CG, the IG reported less disability (1.6 vs 2.0; p = 0.025; d = 0.24) and scored better at the SF-12 physical health scale (43.3 vs 41.0; p < 0.007; d = 0.26). No effect was seen in back pain intensity and in the SF-12 mental health scale. Persons with medium or high risk of back pain chronification at baseline responded better to the health program in all primary outcomes than the subgroup with low risk at baseline.

CONCLUSIONS

After 2 years, the proactive health program resulted in small positive long-term improvements. Using risk screening prior to inclusion in the health program might increase the percentage of participants deriving benefits from it.

TRIAL REGISTRATION

The trial was registered at the German Clinical Trials Register under DRKS00015463 retrospectively (dated 4 Sept 2018).

The cohort multiple randomized controlled trial design: a valid and efficient alternative to pragmatic trials?

Randomized controlled trials (RCTs)-the gold standard for evaluating the effects of medical interventions-are notoriously challenging in terms of logistics, planning and costs. The cohort multiple randomized controlled trial approach is designed to facilitate randomized trials for pragmatic evaluation of (new) interventions and is a promising variation from conventional pragmatic RCTs. In this paper, we evaluate methodological challenges of conducting an RCT within a cohort. We argue that equally valid results can be obtained from trials conducted within cohorts as from pragmatic RCTs. However, whether this design is more efficient compared with conducting a pragmatic RCT depends on the amount and nature of non-compliance in the intervention arm.

Commentary: considerations for using the 'Trials within Cohorts' design in a clinical trial of an investigational medicinal product

Background

The ‘trials within cohorts’ (TwiC) design is a pragmatic approach to randomised trials in which trial participants are randomly selected from an existing cohort. The design has multiple potential benefits, including the option of conducting multiple trials within the same cohort.

Main text

To date, the TwiC design methodology been used in numerous clinical settings but has never been applied to a clinical trial of an investigational medicinal product (CTIMP). We have recently secured the necessary approvals to undertake the first CTIMP using the TwiC design. In this paper, we describe some of the considerations and modifications required to ensure such a trial is compliant with Good Clinical Practice and international clinical trials regulations.

We advocate using a two-stage consent process and using the consent stages to explicitly differentiate between trial participants and cohort participants who are providing control data. This distinction ensured compliance but had consequences with respect to costings, recruitment and the trial assessment schedule.

Conclusion

We have demonstrated that it is possible to secure ethical and regulatory approval for a CTIMP TwiC. By including certain considerations at the trial design stage, we believe this pragmatic and efficient methodology could be utilised in other CTIMPs in future.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2432-3) contains supplementary material, which is available to authorized users.

Methods for assessing and controlling placebo effects

The placebo serves as an indispensable control in many randomized trials. When analyzing the benefit of a new treatment, researchers are often confronted with large placebo effects that diminish the treatment effect. Various alternative methods have been proposed for analyzing placebo and treatment effects in studies where large placebo effects are expected or have already occurred. This paper presents an overview of methodological work that has been proposed for assessing and/or controlling for placebo effects in randomized trials. Throughout this paper, two main approaches are discussed. The first approach considers designs that represent alternatives to the classical placebo-controlled randomized trial design. Separately, the second approach considers adopting new methods for the statistical analysis of placebo and treatment effects to be implemented after the data have been collected using a classical randomized trial design.

Intensive spa and exercise therapy program for returning to work for low back pain patients: a randomized controlled trial

We aimed to determine whether a 5-day intensive inpatient spa and exercise therapy and educational program is more effective than usual care in improving the rate of returning to work at 1 year for patients with subacute and chronic low back pain (LBP) on sick leave for 4 to 24 weeks. We conducted a 12-month randomized controlled trial. LBP patients were assigned to 5-day spa (2 hr/day), exercise (30 min/day) and education (45 min/day) or to usual care. The primary outcome was the percentage of patients returning to work at 1 year after randomization. Secondary outcomes were pain, disability and health-related quality of life at 1 year and number of sick leave days from 6 to 12 months. The projected recruitment was not achieved. Only 88/700 (12.6%) patients planned were enrolled: 45 in the spa therapy group and 43 in the usual care group. At 1 year, returning to work was 56.3% versus 41.9% (OR 1.69 [95% CI 0.60-4.73], p = 0.32) respectively. There was no significant difference for any of the secondary outcomes. However, our study lacked power.

Impact of the Early Start Denver Model on the cognitive level of children with autism spectrum disorder: study protocol for a randomised controlled trial using a two-stage Zelen design

INTRODUCTION

Early intervention for autism spectrum disorder (ASD) in the European French-speaking countries is heterogeneous and poorly evaluated to date. Early intervention units applying the Early Start Denver Model (ESDM) for toddlers and young children with ASD have been created in France and Belgium to improve this situation. It is essential to evaluate this intervention for the political decision-making process regarding ASD interventions in European French-speaking countries. We will evaluate the effectiveness of 12 hours per week ESDM intervention on the cognitive level of children with ASD, over a 2-year period.

METHODS AND ANALYSIS

The study will be a multicentre, randomised controlled trial, using a two-stage Zelen design. Children aged 15-36 months, diagnosed with ASD and with a developmental quotient (DQ) of 30 or above on the Mullen Scale of Early Learning (MSEL) will be included. We will use a stratified minimisation randomisation at a ratio 1:2 in favour of the control group. The sample size required is 180 children (120 in the control and 60 in the intervention group). The experimental group will receive 12 hours per week ESDM by trained therapists 10 hours per week in the centre and 2 hours in the toddlers' natural environment (alternatively by the therapist and the parent). The control group will receive care available in the community. The primary outcome will be the change in cognitive level measured with the DQ of the MSEL scored at 2 years. Secondary outcomes will include change in autism symptoms, behavioural adaptation, communicative and productive language level, sensory profile and parents' quality of life. The primary analysis will use the intention-to-treat principle. An economic evaluation will be performed.

DISSEMINATION

Findings from the study will be disseminated through peer reviewed publications and meetings.

TRIAL REGISTRATION NUMBER

NCT02608333 (clinicaltrials.gov); Pre-results.

[The evaluation of pharmacological drugs, medical devices, and non-pharmacological or public health interventions: Experimental design limitations. Moving towards new methods?]

In the field of health, evidence-based medicine and associated methods like randomised controlled trials (RCTs) have become widely used. RCT has become the gold standard for evaluating causal links between interventions and health results. Originating in pharmacology, this method has been progressively expanded to medical devices, non-pharmacological individual interventions, as well as collective public health interventions. Its use in these domains has led to the formulation of several limits, and it has been called into question as an undisputed gold standard. Some of those limits (e.g. confounding biases and external validity) are common to these four different domains, while others are more specific. This paper describes the different limits, as well as several research avenues. Some are methodological reflections aiming at adapting RCT to the complexity of the tested interventions, and at overcoming some of its limits. Others are alternative methods. The objective is not to remove RCT from the range of evaluation methodologies, but to resituate it within this range. The aim is to encourage choosing between different methods according to the features and the level of the intervention to evaluate, thereby calling for methodological pluralism.

A randomized, controlled trial for risk factor reduction in patients with symptomatic vascular disease: the multidisciplinary Vascular Prevention by Nurses Study (VENUS)

BACKGROUND

Patients with manifest vascular disease are at high risk of a new vascular event or death. Modification of classical risk factors is often not successful. We determined whether the extra care of a nurse practitioner could be beneficial to the cardiovascular risk profile of high-risk patients.

DESIGN

We conducted a randomized, controlled trial based on the Zelen design.

METHODS

Two hundred and thirty-six patients with manifestations of a vascular disease and who had two or more modifiable vascular risk factors were pre-randomized to receive treatment by a nurse practitioner plus usual care or usual care alone. After 1 year, risk factors were remeasured. The primary endpoint was achievement of treatment goals for blood pressure, lipid, glucose and homocysteine levels, body mass index, and smoking.

RESULTS

Of the pre-randomized patients, 95 of 119 (80%) in the intervention group and 80 of 117 (68%) in the control group participated in the study. After a mean follow-up of 14 months, the patients in the intervention group achieved significantly more treatment goals than did the patients in the control group (systolic blood pressure 63 versus 37%, total cholesterol 79 versus 61%, low density lipoprotein-cholesterol 88 versus 67%, and body mass index 38 versus 24%). Medication use was increased in both groups and no differences were found in patients' quality of life (SF-36) at follow-up.

CONCLUSION

Treatment delivered by nurse practitioners, in addition to a vascular risk factor screening and prevention program, resulted in a better management of vascular risk factors than usual care alone in vascular patients after 1-year follow-up.

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.

Alternation as a form of allocation for quality improvement studies in primary healthcare settings: the on-off study design

Background

Randomized controlled trials are considered the “gold standard” for scientific rigor in the assessment of benefits and harms of interventions in healthcare. They may not always be feasible, however, when evaluating quality improvement interventions in real-world healthcare settings. Non-randomized controlled trials (NCTs) are designed to answer questions of effectiveness of interventions in routine clinical practice to inform a decision or process. The on-off NCT design is a relatively new design where participant allocation is by alternation. In alternation, eligible patients are allocated to the intervention “on” or control “off ” groups in time series dependent sequential clusters.

Methods

We used two quality improvement studies undertaken in a Canadian primary care setting to illustrate the features of the on-off design. We also explored the perceptions and experiences of healthcare providers tasked with implementing the on-off study design.

Results and discussion

The on-off design successfully allocated patients to intervention and control groups. Imbalances between baseline variables were attributed to chance, with no detectable biases. However, healthcare providers’ perspectives and experiences with the design in practice reveal some conflict. Specifically, providers described the process of allocating patients to the off group as unethical and immoral, feeling it was in direct conflict with their professional principle of providing care for all. The degree of dissatisfaction seemed exacerbated by: 1) the patient population involved (e.g., patient population viewed as high-risk (e.g., depressed or suicidal)), 2) conducting assessments without taking action (e.g., administering the PHQ-9 and not acting on the results), and 3) the (non-blinded) allocation process.

Conclusions

Alternation, as in the on-off design, is a credible form of allocation. The conflict reported by healthcare providers in implementing the design, while not unique to the on-off design, may be alleviated by greater emphasis on the purpose of the research and having research assistants allocate patients and collect data instead of the healthcare providers implementing the trial. In addition, consultation with front-line staff implementing the trials with an on-off design on appropriateness to the setting (e.g., alignment with professional values and the patient population served) may be beneficial.

Trial registration

Health Eating and Active Living with Diabetes: ClinicalTrials.gov identifier: NCT00991380 Date registered: 7 October 2009.

Controlled trial of a collaborative primary care team model for patients with diabetes and depression: Clintrials.gov Identifier: NCT01328639 Date registered: 30 March 2011.

Use of mobile devices and the internet for multimedia informed consent delivery and data entry in a pediatric asthma trial: Study design and rationale

INTRODUCTION

Phase III/IV clinical trials are expensive and time consuming and often suffer from poor enrollment and retention rates. Pediatric trials are particularly difficult because scheduling around the parent, participant and potentially other sibling schedules can be burdensome. We are evaluating using the internet and mobile devices to conduct the consent process and study visits in a streamlined pediatric asthma trial. Our hypothesis is that these study processes will be non-inferior and will be less expensive compared to a traditional pediatric asthma trial.

MATERIALS/METHODS

Parents and participants, aged 12 through 17 years, complete the informed consent process by viewing a multi-media website containing a consent video and study material in the streamlined trial. Participants are provided an iPad with WiFi and EasyOne spirometer for use during FaceTime visits and online twice daily symptom reporting during an 8-week run-in followed by a 12-week study period. Outcomes are compared with participants completing a similarly designed traditional trial comparing the same treatments within the same pediatric health-system. After 8 weeks of open-label Advair 250/50 twice daily, participants in both trial types are randomized to Advair 250/50, Flovent 250, or Advair 100/50 given 1 inhalation twice daily. Study staff track time spent to determine study costs.

RESULTS

Participants have been enrolled in the streamlined and traditional trials and recruitment is ongoing.

CONCLUSIONS

This project will provide important information on both clinical and economic outcomes for a novel method of conducting clinical trials. The results will be broadly applicable to trials of other diseases.

The delivery of chemotherapy at home: an evidence synthesis

Background

Recent policy and guidance has focused on chemotherapy services being offered closer to home, but the clinical and economic implications of this are uncertain.

Objectives

To compare the impact of delivering intravenous chemotherapy in different settings on a range of outcomes, including quality of life, safety and costs.

Design

Multimethods approach: systematic review of clinical effectiveness, qualitative and cost-effectiveness studies; description of the patient pathway and brief survey of current provision; and development of a decision model to explore aspects of cost-effectiveness.

Setting

Provision of intravenous chemotherapy.

Participants

Chemotherapy patients.

Interventions

Setting in which chemotherapy was administered (home, community or outpatient).

Outcome measures

Safety, quality of life, preference, satisfaction, opinions/experiences, social functioning, clinical outcomes, costs and resource/organisational issues.

Data sources

Sixteen electronic databases (including MEDLINE, EMBASE and The Cochrane Library) were searched from inception to October 2013 for published and unpublished studies.

Review methods

Two reviewers independently screened potentially relevant studies, extracted data and quality assessed the included studies. Study validity was evaluated using appropriate quality assessment tools. Clinical effectiveness and cost-effectiveness studies were summarised narratively, and qualitative studies were synthesised using meta-ethnography.

Results

Of the 67 eligible studies, 25 were comparative, with nine including a concurrent economic evaluation. Although some of the 10 randomised trials were designed to minimise avoidable biases, slow recruitment rates and non-participation of eligible patients for setting-related reasons meant that trial sample sizes were small and populations were inherently biased to favour the home or community settings. There was little evidence to suggest differences between settings in terms of quality of life, clinical outcomes, psychological outcomes or adverse events. All nine economic evaluations were judged as having low or uncertain quality, providing limited evidence to draw overall conclusions. Most were cost–consequence analyses, presenting cost outcomes alongside trial results but deriving no summary measure of benefit. Poor resource use reporting and use of different perspectives across settings made results difficult to compare. Seventeen qualitative studies (450 participants) were judged as moderate to good quality, although all compared new or proposed services with existing outpatient facilities and biased samples were used. The three main lines of argument were barriers to service provision, satisfaction with chemotherapy and making compromises to maintain normality. Most patients made explicit trade-offs between the time and energy required for outpatient chemotherapy, which reduced quality of life, and an increased sense of safety. A patient pathway was described, informed by expert advice and a brief survey of NHS and private providers, which identified wide variation in the ways in which home and community chemotherapy was delivered. Considering limitations of the available data and variation in provision, cost-effectiveness modelling results were not robust and were viewed as exploratory only; the results were highly unstable.

Conclusions

Primary studies comparing settings for administering intravenous chemotherapy appear difficult to conduct. Consequently, few robust conclusions can be made about the clinical effectiveness and cost-effectiveness. Qualitative studies indicate that the patient time and energy required for outpatient chemotherapy reduces quality of life. A nested randomised controlled trial within a larger observational cohort of patients is proposed to enhance recruitment and improve generalisability of results. Future economic evaluations require detailed patient characteristic, resource use, cost and quality-of-life data, although their results are likely to have limited generalisability.

Study registration

This study is registered as PROSPERO CRD42013004851.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

What can we learn from a failed trial: insight into non-participation in a chat-based intervention trial for adolescents with psychosocial problems

BACKGROUND

Psychosocial problems are highly prevalent among Dutch adolescents. We have conducted a trial to test whether offering chat-based consultations could be of added value within the context of Dutch Youth Health Care. This trial was ended prematurely because of recruitment issues. The aim of this study is to learn from this failed trial and to provide more insight into non-participation. Sources of data were non-participation forms, oral clarification, patient records, telephone interviews with adolescents that declined to participate, and a questionnaire-based process evaluation among nurses.

RESULTS

Non-participation appears to be a multi-factorial problem. Of those 290 adolescents eligible to participate, the majority (n = 165, 57%) declined to do so. Two-third of those (n = 109) also refused usual care, which might be indicative of not wanting help and/or experiencing problems and the validity of the assessment instrument. The other one-third (n = 56) did enrol in usual care and indicated other reasons for non-participation, such as a preference for face-to-face consultations, the extensive information that was provided, and not liking the idea of being randomized.

CONCLUSIONS

This study shows that even if a trial fails, we can learn about the challenges of recruiting adolescents in intervention trials.

TRIAL REGISTRATION

NL37668.068.11/METC11-3-077.

Insuring the integrity and validity of social work interventions: the case of the subsidized guardianship waiver experiments

The near loss of the ability to conduct randomized controlled trials in the Title IV-E waiver demonstrations makes the negotiation of a ceasefire urgent in the "causal wars." Results-oriented accountability is a conceptual framework for managing the micro-macro tensions that arise in social work practice and research. This article uses subsidized guardianship experiments to illustrate the results-oriented accountability process by which innovation is aggregated from the micro level through formative implementation and evaluation into a usable, stable intervention that can be rigorously tested through summative implementation and evaluation at the macro level, and if validated, generalized to the micro level through translative implementation and evaluation.

Is a randomised controlled trial of a maternity care intervention for pregnant adolescents possible? An Australian feasibility study

Background

The way in which maternity care is provided affects perinatal outcomes for pregnant adolescents; including the likelihood of preterm birth. The study purpose was to assess the feasibility of recruiting pregnant adolescents into a randomised controlled trial, in order to inform the design of an adequately powered trial which could test the effect of caseload midwifery on preterm birth for pregnant adolescents.

Methods

We recruited pregnant adolescents into a feasibility study of a prospective, un-blinded, two-arm, randomised controlled trial of caseload midwifery compared to standard care. We recorded and analysed recruitment data in order to provide estimates to be used in the design of a larger study.

Results

The proportion of women aged 15–17 years who were eligible for the study was 34% (n=10), however the proportion who agreed to be randomised was only 11% (n = 1). Barriers to recruitment were restrictive eligibility criteria, unwillingness of hospital staff to assist with recruitment, and unwillingness of pregnant adolescents to have their choice of maternity carer removed through randomisation.

Conclusions

A randomised controlled trial of caseload midwifery care for pregnant adolescents would not be feasible in this setting without modifications to the research protocol. The recruitment plan should maximise opportunities for participation by increasing the upper age limit and enabling women to be recruited at a later gestation. Strategies to engage the support of hospital-employed staff are essential and would require substantial, and ongoing, work. A Zelen method of post-randomisation consent, monetary incentives and ‘peer recruiters’ could also be considered.

Alternatives for randomization in lifestyle intervention studies in cancer patients were not better than conventional randomization

OBJECTIVE

Assessing effects of lifestyle interventions in cancer patients has some specific challenges. Although randomization is urgently needed for evidence-based knowledge, sometimes it is difficult to apply conventional randomization (i.e., consent preceding randomization and intervention) in daily settings. Randomization before seeking consent was proposed by Zelen, and additional modifications were proposed since. We discuss four alternatives for conventional randomization: single and double randomized consent design, two-stage randomized consent design, and the design with consent to postponed information.

STUDY DESIGN AND SETTING

We considered these designs when designing a study to assess the impact of physical activity on cancer-related fatigue and quality of life. We tested the modified Zelen design with consent to postponed information in a pilot. The design was chosen to prevent drop out of participants in the control group because of disappointment about the allocation.

RESULTS

The result was a low overall participation rate most likely because of perceived lack of information by eligible patients and a relatively high dropout in the intervention group.

CONCLUSION

We conclude that the alternatives were not better than conventional randomization.

Risk factors for early treatment discontinuation in patients with obsessive-compulsive disorder

INTRODUCTION

In obsessive-compulsive disorder, early treatment discontinuation can hamper the effectiveness of first-line treatments.

OBJECTIVE

This study aimed to investigate the clinical correlates of early treatment discontinuation among obsessive-compulsive disorder patients.

METHODS

A group of patients who stopped taking selective serotonin reuptake inhibitors (SSRIs) or stopped participating in cognitive behavioral therapy before completion of the first twelve weeks (total n = 41; n = 16 for cognitive behavioral therapy and n = 25 for SSRIs) were compared with a paired sample of compliant patients (n = 41). Demographic and clinical characteristics were obtained at baseline using structured clinical interviews. Chi-square and Mann-Whitney tests were used when indicated. Variables presenting a p value <0.15 for the difference between groups were selected for inclusion in a logistic regression analysis that used an interaction model with treatment dropout as the response variable.

RESULTS

Agoraphobia was only present in one (2.4%) patient who completed the twelve-week therapy, whereas it was present in six (15.0%) patients who dropped out (p = 0.044). Social phobia was present in eight (19.5%) patients who completed the twelve-week therapy and eighteen (45%) patients who dropped out (p = 0.014). Generalized anxiety disorder was present in eight (19.5%) patients who completed the twelve-week therapy and twenty (50%) dropouts (p = 0.004), and somatization disorder was not present in any of the patients who completed the twelve-week therapy; however, it was present in six (15%) dropouts (p = 0.010). According to the logistic regression model, treatment modality (p = 0.05), agoraphobia, the Brown Assessment of Beliefs Scale scores (p = 0.03) and the Beck Anxiety Inventory (p = 0.02) scores were significantly associated with the probability of treatment discontinuation irrespective of interactions with other variables.

DISCUSSION AND CONCLUSION

Early treatment discontinuation is a common phenomenon in obsessive-compulsive disorder patients from our therapeutic setting. Psychiatric comorbidities were associated with discontinuation rates of specific treatments. Future studies might use this information to improve management for increased compliance and treatment effectiveness.

Dealing with Missing Outcomes: Lessons from a Randomized Trial of a Prenatal Intervention to Prevent Early Childhood Caries

Severe early childhood caries (S-ECC) affects 17% of 2-3 year old children in South Australia impacting on their general health and well-being. S-ECC is largely preventable by providing mothers with anticipatory guidance. Randomised controlled trials (RCTs) are the most decisive way to test this, but that approach suffers from near inevitable loss to follow-up that occurs with preventative strategies and distant outcome assessment.

We re-examined the results of an RCT to prevent S-ECC using sensitivity analyses and multiple imputation to test different assumptions about violation of random allocation (1%) and major loss to follow-up (32%). Irrespective of any assumptions about missing outcomes, providing expectant mothers with anticipatory guidance during pregnancy and in the child’s first year of life, significantly reduced the incidence of S-ECC at 20 months of age. However, the relative risk of S-ECC varied from 0.18 (95% confidence interval (CI): 0.06 – 0.52) to 0.70 (95% CI: 0.56 – 0.88). Also the ‘number needed to treat’ (NNT) to prevent one case of S-ECC varied 2.5-fold: from 8 to 20 women given anticipatory guidance. Multiple imputation provided a best estimate of 0.25 (95% CI: 0.11 – 0.56) for the relative risk and of 14 (95% CI: 10 – 33) for the number needed to treat.

Avoiding loss to follow-up is crucial in any RCT, but is difficult with preventative health care strategies. Instead of abandoning randomisation in such circumstances, sensitivity analyses and multiple imputation can consolidate the findings of an RCT and add extra value to the conclusions derived from it.

Noncompliance in lifestyle intervention studies: the instrumental variable method provides insight into the bias

OBJECTIVE

In lifestyle intervention trials, participants of the control group often change their behavior despite the request to maintain their usual lifestyle pattern. These changes in the control group and changes in addition to the intended in the intervention group can lead to undesirable confounding effects.

STUDY DESIGN AND SETTING

We address several considerations for study design to prevent noncompliance or minimize its effects. Furthermore, we demonstrate how the instrumental variable method can give insight into the extent of bias introduced by noncompliance in randomized trials, within the context of the Sex Hormones and Physical Exercise study.

RESULTS

Noncompliance can be prevented by measures taken in the design phase of a study, for example, limited duration of the study, clear recommendations, power calculation, intensity of the intervention, involvement of the control group, waiting-list control group, and single-consent design nested within an observational study. When nevertheless noncompliance does occur, the instrumental variable method estimates the intervention effect of treatment among the compliers.

CONCLUSION

Noncompliance can seriously affect validity of lifestyle trial results. Its occurrence should be prevented by taking measures during the design phase of a study. The instrumental variable method can give insight into confounding by noncompliance in randomized trials.

Overcoming the barriers experienced in conducting a medication trial in adults with aggressive challenging behaviour and intellectual disabilities

BACKGROUND

Aggressive challenging behaviour in people with intellectual disability (ID) is frequently treated with antipsychotic drugs, despite a limited evidence base.

METHOD

A multi-centre randomised controlled trial was undertaken to investigate the efficacy, adverse effects and costs of two commonly prescribed antipsychotic drugs (risperidone and haloperidol) and placebo.

RESULTS

The trial faced significant problems in recruitment. The intent was to recruit 120 patients over 2 years in three centres and to use a validated aggression scale (Modified Overt Aggression Scale) score as the primary outcome. Despite doubling the period of recruitment, only 86 patients were ultimately recruited.

CONCLUSIONS

Variation in beliefs over the efficacy of drug treatment, difficulties within multidisciplinary teams and perceived ethical concerns over medication trials in this population all contributed to poor recruitment. Where appropriate to the research question cluster randomised trials represent an ethically and logistically feasible alternative to individually randomised trials.

Intensive Smoking-cessation Intervention in the Dental Setting

Smoking exerts detrimental effects on dental treatment and oral health. Our goal was to evaluate effectiveness in terms of the abstinence rate in smoking-cessation intervention delivered by dental professionals. Individuals who were willing to quit smoking were randomly assigned to either an intervention or a non-intervention group. Intensive intervention was provided, consisting of 5 counseling sessions, including an additional nicotine replacement regimen. Reported abstinence was verified by the salivary cotinine level. Thirty-three persons in the intervention and 23 in the non-intervention group started the trial. On an intent-to-treat basis, 3-, 6- and 12-month continuous abstinence rates in the intervention group were 51.5%, 39.4%, and 36.4%, respectively, while the rates in the non-intervention group were consistent at 13.0%. Adjusted odds ratios (95% confidence interval) by logistic stepwise regression analyses were 7.1 (1.8, 28.5), 8.9 (1.7, 47.2), and 6.4 (1.3, 30.7), respectively. Intensive smoking-cessation intervention in the dental setting was therefore effective.

Healthcare provided by a homeopath as an adjunct to usual care for Fibromyalgia (FMS): results of a pilot Randomised Controlled Trial

OBJECTIVES

To assess the feasibility of a Randomised Controlled Trial (RCT) design of usual care compared with usual care plus adjunctive care by a homeopath for patients with Fibromyalgia syndrome (FMS).

METHODS

In a pragmatic parallel group RCT design, adults with a diagnosis of FMS (ACR criteria) were randomly allocated to usual care or usual care plus adjunctive care by a homeopath. Adjunctive care consisted of five in depth interviews and individualised homeopathic medicines. The primary outcome measure was the difference in Fibromyalgia Impact Questionnaire (FIQ) total score at 22 weeks.

RESULTS

47 patients were recruited. Drop out rate in the usual care group was higher than the homeopath care group (8/24 vs 3/23). Adjusted for baseline, there was a significantly greater mean reduction in the FIQ total score (function) in the homeopath care group than the usual care group (-7.62 vs 3.63). There were significantly greater reductions in the homeopath care group in the McGill pain score, FIQ fatigue and tiredness upon waking scores. We found a small effect on pain score (0.21, 95% CI -1.42 to 1.84); but a large effect on function (0.81, 95% CI -8.17 to 9.79). There were no reported adverse events.

CONCLUSIONS

Given the acceptability of the treatment and the clinically relevant effect on function, there is a need for a definitive study to assess the clinical and cost effectiveness of adjunctive healthcare by a homeopath for patients with FMS.

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 HIM (Health for Izhevsk Men) trial protocol

BACKGROUND

Russia is one of the very few industrialised countries in the world where life expectancy has been declining. Alcohol has been implicated as a major contributor to the rapid fluctuations observed in male life expectancy since 1985 that have been particularly marked among working-age men. One approach to reducing the alcohol problem in Russia is 'brief interventions' which seek to change views of the personal acceptability of excessive drinking and to encourage self-directed behaviour change. There is limited understanding in Russia of the salience and applicability of Motivational Interviewing (MI), a well-defined brief intervention commonly used to target alcohol-related behaviour, but MI may have important potential for success within the Russian context.

METHODS/DESIGN

The study will be an individually randomised two-armed parallel group exploratory trial. The primary hypothesis is that a brief adaptation of MI will be effective in reducing self-reported hazardous drinking at 3 months. The secondary hypothesis is that it will be effective in reducing self-reported past week beverage alcohol consumption, alcohol dependence and related problems at 3 months and at 12 months. MI will also be effective at 12 months in reducing self-reported hazardous drinking, alcohol dependence and related problems, proxy reported hazardous drinking, and recent alcohol use as indicated by bio-markers. Participants are drawn from the Izhevsk Family Study II, with eligibility determined based on proxy reports of hazardous drinking in the past year. All participants undergo a health check, with MI subsequently delivered to those in the intervention arm. Signed consent is obtained from those in the intervention arm at this point. Both groups are then invited for 3 and 12 month follow ups. The control group will not receive any additional intervention.

TRIAL REGISTRATION

ISRCTN82405938.

Randomized consent designs in randomized controlled trials: Systematic literature search

BACKGROUND

Three types of randomized consent designs are distinguished and ranked according to the extent to which participants are informed about treatment options: single-consent (those in the experimental group learn about their assigned treatment), incomplete-double-consent (all participants learn about their assigned treatment), and complete-double-consent (all participants learn about all treatments studied). All are methodologically, ethically, and judicially controversial. Even so, their use is justified if blinding is deemed necessary, but impossible to achieve by sham procedures (placebo), and experimental treatment seems attractive to potential participants.

OBJECTIVE

The aim of this study is to give a comprehensive overview of the use of randomized consent designs. Data sources are MEDLINE (1/1977-2/2003), EMBASE (1/1984-2/2003), PsycINFO (1/1996-2/2003), the Cochrane Library, and the Science Citation Index database.

REVIEW METHODS

Eligible were studies using a randomized consent design. Cluster randomized trials were excluded. One reviewer selected and data-extracted eligible papers. A second reviewer independently data-extracted 10% of the papers. Data on country of study conduct, year of commencement, area of medicine, type of design, reason(s) for use, details on approval by a research ethics committee, the index and reference intervention, nature of endpoints, and details on collection of data were extracted. Furthermore, for each trial, the rates of non-compliance and loss to follow-up were registered by treatment arm. The three types of randomized consent designs were compared as to differences between the rates of non-compliance and loss to follow-up in the separate trial arms.

RESULTS

Randomized consent designs are seldom used (n=50). When used, they have often been used in the wrong circumstances (misuse). In 65% of the studies the non-compliance in the index group is larger than in the reference group. Contrary to expectation, trials using the incomplete-double design were associated with significantly higher rates of non-compliance and loss to follow-up in the reference groups than trials employing the other two versions.

CONCLUSION

Trialists and physicians should be aware of the proper indication for the use of randomized consent designs.