The Rise of Adaptive Platform Trials in Critical Care

Evidence-based personalised medicine in critical care: a framework for quantifying and applying individualised treatment effects in patients who are critically ill

Clinicians aim to provide treatments that will result in the best outcome for each patient. Ideally, treatment decisions are based on evidence from randomised clinical trials. Randomised trials conventionally report an aggregated difference in outcomes between patients in each group, known as an average treatment effect. However, the actual effect of treatment on outcomes (treatment response) can vary considerably between individuals, and can differ substantially from the average treatment effect. This variation in response to treatment between patients-heterogeneity of treatment effect-is particularly important in critical care because common critical care syndromes (eg, sepsis and acute respiratory distress syndrome) are clinically and biologically heterogeneous. Statistical approaches have been developed to analyse heterogeneity of treatment effect and predict individualised treatment effects for each patient. In this Review, we outline a framework for deriving and validating individualised treatment effects and identify challenges to applying individualised treatment effect estimates to inform treatment decisions in clinical care.

A Decision-Making Grid for Coenrollment in Multiple Clinical Trials

BACKGROUND

Although subject coenrollment into multiple trials is desirable, thoughtful consideration is required to avoid compromising each trial's scientific integrity.

OBJECTIVE

We developed a Decision-Making Grid (GRID) to help investigators determine whether a clinical trial is compatible with a second clinical trial, thus allowing coenrollment, or if it should be considered competing, prohibiting coenrollment.

METHODS

The GRID evaluates 21 elements across four domains: scientific integrity, data interpretation, feasibility/burden, and additional considerations. Optimally, each principal investigator shares their protocol, completes the GRID independently, and then meets to compare their perspectives, seeking a mutually acceptable agreement.

RESULTS

The GRID has facilitated coenrollment decision-making for the RESTORE and PROSpect pediatric critical care clinical trials. In RESTORE , five trials were reviewed; one was approved for coenrollment, and four were deemed competing. In PROSpect , 26 trials have been reviewed; 20 are approved for coenrollment, and six were deemed competing. In both RESTORE and PROSpect , the principal investigators of multiple trials arranged a mutually acceptable sharing agreement.

DISCUSSION

The GRID provides a systematic process to help investigators evaluate the effect of coenrollment in multiple clinical trials.

CAEP 2024 Academic Symposium: adaptive platform trials in emergency medicine in Canada

OBJECTIVE

The Canadian Association of Emergency Physicians 2024 Academic Symposium Panel on adaptive platform trials explored whether adaptive platform trials could be implemented in Canadian emergency departments (EDs). This panel aimed to propose and refine recommendations formulated by the results of a rapid review and responses from a panel of experts about conducting adaptive platform trials in EDs.

METHODS

From November 2023 to May 2024, a rapid review was conducted on the existing logistical and ethical barriers and facilitators to structuring adaptive platform trials in emergency medicine. The emerging themes and ideas were collected and used to conduct individual semi-structured interviews with key stakeholders, including leaders in emergency medicine research, methodologists and biostatisticians specializing in these designs, patient partners, research personnel, and investigators involved in platform trials across Canada and abroad.

RESULTS

From 23 articles and 17 expert interviews, we identified facilitators and barriers to adaptive platform trials in Canadian emergency medicine spread across five domains: evidence strength and quality, relative advantage, adaptability, complexity, and implementation climate and readiness. The most salient needs according to investigators were purposeful and clinically relevant trial design, methodological expertise, and harmonious collaboration with ethics authorities. We provide 14 recommendations across 4 levels: policy, trialist, site, and patient to address barriers to adaptive platform trials in emergency medicine. For each recommendation, we provided corresponding implementation strategies from the Expert Recommendations for Implementing Change (ERIC).

CONCLUSIONS

Adaptive trial designs are well suited for emergency settings provided the interventions are both easy for clinicians to administer and relevant enough to ameliorate the practice of emergency medicine. These designs are particularly tailored to tackle confirmatory trials, emerging diseases, and trauma care, but barriers like a chaotic ED, complex statistical and methodological requirements, and regulatory considerations persist and require thoughtful implementation strategies.

The "Small" Clinical Trial: Methods, Analysis, and Interpretation in Acute Care Cardiology

Clinical trials in acute care settings, particularly those involving small populations or high mortality contexts, present unique challenges in design and analysis. In this review we explore novel statistical approaches and methodological considerations for such trials, with a focus on cardiovascular therapies. We discuss the concept of "small" sample sizes and their limitations and cover various analytical frameworks, including frequentist and Bayesian approaches, and emphasize their implications for result interpretation and reproducibility. We examine end points such as "days alive and free specific to disease state," which combines mortality and morbidity measures, the win ratio for hierarchical end points, and ordinal scales that capture detailed patient outcomes. These methods potentially increase statistical power and provide more clinically relevant measures compared with traditional binary outcomes; an extensive use of simulations is used to clarify this point. The use of longitudinal ordinal models is presented as a promising method to capture complex patient trajectories over time, offering insights into treatment effects at various disease stages. We also address the potential of adaptive platform trials for rare conditions, allowing for more efficient use of limited patient populations. In this overview we aim to guide researchers and clinicians in selecting optimal trial designs and analytical strategies, to ultimately improve the quality, efficiency, and interpretability of evidence in acute care cardiology.

Past, present, and future of Phase 3 vaccine trial design: rethinking statistics for the 21st century

Vaccines are crucial for protecting health globally; however, their widespread use relies on rigorous clinical development programmes. This includes Phase 3 randomized controlled trials (RCTs) to confirm their safety, immunogenicity, and efficacy. Traditionally, such trials used fixed designs with predetermined assumptions, lacking the flexibility to change during the trial or stop early due to overwhelming evidence of either efficacy or futility. Modern vaccine trials benefit from innovative approaches like adaptive designs, allowing for planned trial adaptations based on accumulating data. Here, we provide an overview of the evolution of Phase 3 vaccine trial design and statistical analysis methods from traditional to more innovative contemporary methods. This includes adaptive trial designs, which offer ethical advantages and enable early termination if indicated; Bayesian methods, which combine prior knowledge and observed trial data to increase efficiency and enhance result interpretation; modern statistical analysis methods, which enable more accurate and precise inferences; the estimand framework, which ensures the primary question of interest is addressed in a trial; novel approaches using machine learning methods to assess heterogeneity of treatment effects; and statistical advances in safety analysis to evaluate reactogenicity and clinical adverse events. We conclude with insights into the future direction of vaccine trials, aiming to inform clinicians and researchers about conventional and novel RCT design and analysis approaches to facilitate the conduct of efficient, timely trials.

Framework for Research Gaps in Pediatric Ventilator Liberation

BACKGROUND

The 2023 International Pediatric Ventilator Liberation Clinical Practice Guidelines provided evidence-based recommendations to guide pediatric critical care providers on how to perform daily aspects of ventilator liberation. However, because of the lack of high-quality pediatric studies, most recommendations were conditional based on very low to low certainty of evidence.

RESEARCH QUESTION

What are the research gaps related to pediatric ventilator liberation that can be studied to strengthen the evidence for future updates of the guidelines?

STUDY DESIGN AND METHODS

We conducted systematic reviews of the literature in eight predefined Population, Intervention, Comparator, Outcome (PICO) areas related to pediatric ventilator liberation to generate recommendations. Subgroups responsible for each PICO question subsequently identified major research gaps by synthesizing the literature. These gaps were presented at an international symposium at the Pediatric Acute Lung Injury and Sepsis Investigators meeting in spring 2022 for open discussion. Feedback was incorporated, and final evaluation of research gaps are summarized herein. Although randomized controlled trials (RCTs) represent the highest level of evidence, the panel sought to highlight areas where alternative study designs also may be appropriate, given challenges with conducting large multicenter RCTs in children.

RESULTS

Significant research gaps were identified in six broad areas related to pediatric ventilator liberation. Several of these areas necessitate multicenter RCTs to provide definitive results, whereas other gaps can be addressed with multicenter observational studies or quality improvement initiatives. Furthermore, a need for some physiologic studies in several areas remains, particularly regarding newer diagnostic methods to improve identification of patients at high risk of extubation failure.

INTERPRETATION

Although pediatric ventilator liberation guidelines have been created, the certainty of evidence remains low and multiple research gaps exist that should be bridged through high-quality RCTs, multicenter observational studies, and quality improvement initiatives.

Acute respiratory distress syndrome

The understanding of acute respiratory distress syndrome (ARDS) has evolved greatly since it was first described in a 1967 case series, with several subsequent updates to the definition of the syndrome. Basic science advances and clinical trials have provided insight into the mechanisms of lung injury in ARDS and led to reduced mortality through comprehensive critical care interventions. This review summarizes the current understanding of the epidemiology, pathophysiology, and management of ARDS. Key highlights include a recommended new global definition of ARDS and updated guidelines for managing ARDS on a backbone of established interventions such as low tidal volume ventilation, prone positioning, and a conservative fluid strategy. Future priorities for investigation of ARDS are also highlighted.