ABSTRACT
BACKGROUND: Concerns have been raised about the long-term performance of aortic stent grafts for the treatment of abdominal aortic aneurysms, in particular, unibody stent grafts (eg, Endologix AFX AAA stent grafts). Only limited data sets are available to evaluate the long-term risks related to these devices. The SAFE-AAA Study (Comparison of Unibody and Non-Unibody Endografts for Abdominal Aortic Aneurysm Repair in Medicare Beneficiaries Study) was designed with the Food and Drug Administration to provide a longitudinal assessment of the safety of unibody aortic stent grafts among Medicare beneficiaries. METHODS: The SAFE-AAA Study was a prespecified, retrospective cohort study evaluating whether unibody aortic stent grafts are noninferior to non-unibody aortic stent grafts with respect to the composite primary outcome of aortic reintervention, rupture, and mortality. Procedures were evaluated from August 1, 2011, through December 31, 2017. The primary end point was evaluated through December 31, 2019. Inverse probability weighting was used to account for imbalances in observed characteristics. Sensitivity analyses were used to evaluate the effect of unmeasured confounding, including assessment of the falsification end points heart failure, stroke, and pneumonia. A prespecified subgroup included patients treated from February 22, 2016, through December 31, 2017, corresponding to the market release of the most contemporary unibody aortic stent grafts (Endologix AFX2 AAA stent graft). RESULTS: Of 87 163 patients who underwent aortic stent grafting at 2146 US hospitals, 11 903 (13.7%) received a unibody device. The average age of the total cohort was 77.0±6.7 years, 21.1% were female, 93.5% were White, 90.8% had hypertension, and 35.8% used tobacco. The primary end point occurred in 73.4% of unibody device-treated patients versus 65.0% of non-unibody device-treated patients (hazard ratio, 1.19 [95% CI, 1.15-1.22]; noninferior P value of 1.00; median follow-up, 3.4 years). Falsification end points were negligibly different between groups. In the subgroup treated with contemporary unibody aortic stent grafts, the cumulative incidence of the primary end point occurred in 37.5% of unibody device-treated patients and 32.7% of non-unibody device-treated patients (hazard ratio, 1.06 [95% CI, 0.98-1.14]). CONCLUSIONS: In the SAFE-AAA Study, unibody aortic stent grafts failed to meet noninferiority compared with non-unibody aortic stent grafts with respect to aortic reintervention, rupture, and mortality. These data support the urgency of instituting a prospective longitudinal surveillance program for monitoring safety events related to aortic stent grafts.
Subject(s)
Aortic Aneurysm, Abdominal , Blood Vessel Prosthesis Implantation , Endovascular Procedures , Humans , Female , Aged , United States , Aged, 80 and over , Male , Blood Vessel Prosthesis , Blood Vessel Prosthesis Implantation/adverse effects , Retrospective Studies , Prospective Studies , Treatment Outcome , Endovascular Procedures/adverse effects , Medicare , Stents , Prosthesis DesignABSTRACT
The Shock Academic Research Consortium is a multi-stakeholder group, including representatives from the US Food and Drug Administration and other government agencies, industry, and payers, convened to develop pragmatic consensus definitions useful for the evaluation of clinical trials enrolling patients with cardiogenic shock, including trials evaluating mechanical circulatory support devices. Several in-person and virtual meetings were convened between 2020 and 2022 to discuss the need for developing the standardized definitions required for evaluation of mechanical circulatory support devices in clinical trials for cardiogenic shock patients. The expert panel identified key concepts and topics by performing literature reviews, including previous clinical trials, while recognizing current challenges and the need to advance evidence-based practice and statistical analysis to support future clinical trials. For each category, a lead (primary) author was assigned to perform a literature search and draft a proposed definition, which was presented to the subgroup. These definitions were further modified after feedback from the expert panel meetings until a consensus was reached. This manuscript summarizes the expert panel recommendations focused on outcome definitions, including efficacy and safety.
Subject(s)
Heart Valve Prosthesis Implantation , Heart-Assist Devices , Humans , Shock, Cardiogenic/therapy , Shock, Cardiogenic/surgery , Research DesignABSTRACT
Antiplatelet therapy is the mainstay of pharmacologic treatment to prevent thrombotic or ischemic events in patients with coronary artery disease treated with percutaneous coronary intervention and those treated medically for an acute coronary syndrome. The use of antiplatelet therapy comes at the expense of an increased risk of bleeding complications. Defining the optimal intensity of platelet inhibition according to the clinical presentation of atherosclerotic cardiovascular disease and individual patient factors is a clinical challenge. Modulation of antiplatelet therapy is a medical action that is frequently performed to balance the risk of thrombotic or ischemic events and the risk of bleeding. This aim may be achieved by reducing (ie, de-escalation) or increasing (ie, escalation) the intensity of platelet inhibition by changing the type, dose, or number of antiplatelet drugs. Because de-escalation or escalation can be achieved in different ways, with a number of emerging approaches, confusion arises with terminologies that are often used interchangeably. To address this issue, this Academic Research Consortium collaboration provides an overview and definitions of different strategies of antiplatelet therapy modulation for patients with coronary artery disease, including but not limited to those undergoing percutaneous coronary intervention, and consensus statements on standardized definitions.
Subject(s)
Acute Coronary Syndrome , Coronary Artery Disease , Percutaneous Coronary Intervention , Thrombosis , Humans , Platelet Aggregation Inhibitors/adverse effects , Coronary Artery Disease/complications , Hemorrhage/etiology , Blood Platelets , Dual Anti-Platelet Therapy/adverse effects , Acute Coronary Syndrome/therapy , Thrombosis/etiology , Percutaneous Coronary Intervention/adverse effects , Treatment OutcomeABSTRACT
The care of patients with heart rhythm disorders is often dependent on technologies developed to address their unique clinical needs. Although much innovation occurs in the United States, recent decades have seen a significant proportion of early clinical studies performed outside the United States, driven largely by costly and time-inefficient processes seemingly inherent to the United States research ecosystem. As a result, the goals of early patient access to novel devices to address unmet needs and efficient technology development in the United States remain incompletely realized. This review will introduce key aspects of this discussion, organized by the Medical Device Innovation Consortium, in an effort to broaden awareness and encourage engagement by stakeholders in an effort to address central issues and therefore further a growing effort to shift Early Feasibility Studies to the United States for the benefit of all involved.
Subject(s)
Cardiac Electrophysiology , Ecosystem , Humans , United States , Feasibility StudiesABSTRACT
Registry Assessment of Peripheral Interventional Devices (RAPID) initiated the Pathways Program to provide a transparent, collaborative forum in which to pursue insights into multiple unresolved questions on benefit-risk of paclitaxel-coated devices, including understanding the basis of the mortality signal, without a demonstrable potential biological mechanism, and whether the late mortality signal could be artifact intrinsic to multiple independent prospective randomized data sources that did not prespecify death as a long-term end point. In response to the directive, the LEAN-Case Report Form working group focused on enhancements to the RAPID Phase I Minimum Core Data set through the addition of key clinical modifiers that would be more strongly linked to longer-term mortality outcomes after peripheral arterial disease intervention in the drug-eluting device era, with the goal to have future mortality signals more accurately examined.
ABSTRACT
Over the past 2 decades, chronic total occlusion (CTO) percutaneous coronary intervention has developed into its own subspecialty of interventional cardiology. Dedicated terminology, techniques, devices, courses, and training programs have enabled progressive advancements. However, only a few randomized trials have been performed to evaluate the safety and efficacy of CTO percutaneous coronary intervention. Moreover, several published observational studies have shown conflicting data. Part of the paucity of clinical data stems from the fact that prior studies have been suboptimally designed and performed. The absence of standardized end points and the discrepancy in definitions also prevent consistency and uniform interpretability of reported results in CTO intervention. To standardize the field, we therefore assembled a broad consortium comprising academicians, practicing physicians, researchers, medical society representatives, and regulators (US Food and Drug Administration) to develop methods, end points, biomarkers, parameters, data, materials, processes, procedures, evaluations, tools, and techniques for CTO interventions. This article summarizes the effort and is organized into 3 sections: key elements and procedural definitions, end point definitions, and clinical trial design principles. The Chronic Total Occlusion Academic Research Consortium is a first step toward improved comparability and interpretability of study results, supplying an increasingly growing body of CTO percutaneous coronary intervention evidence.
Subject(s)
Coronary Occlusion/therapy , Coronary Vessels/physiology , Clinical Trials as Topic , Female , Humans , MaleABSTRACT
BACKGROUND: Clinical events committee (CEC) evaluation is the standard approach for end point adjudication in clinical trials. Due to resource constraints, large registries typically rely on site-reported end points without further confirmation, which may preclude use for regulatory oversight. METHODS: We developed a novel automated adjudication algorithm (AAA) for end point adjudication in the National Cardiovascular Data Registry Left Atrial Appendage Occlusion (LAAO) Registry using an iterative process using CEC adjudication as the "gold standard." A ≥80% agreement rate between automated algorithm adjudication and CEC adjudication was prespecified as clinically acceptable. Agreement rates were calculated. RESULTS: A total of 92 in-hospital and 127 post-discharge end points were evaluated between January 1, 2016 and June 30, 2019 using AAA and CEC. Agreement for neurologic events was >90%. Percent agreement for in-hospital and post-discharge events was as follows: ischemic stroke 95.7% and 94.5%, hemorrhagic stroke 97.8% and 96.1%, undetermined stroke 97.8% and 99.2%, transient ischemic attack 98.9% and 98.4% and intracranial hemorrhage 100.0% and 94.5%. Agreement was >80% for major bleeding (83.7% and 90.6%) and major vascular complication (89.1% and 97.6%). With this approach, <1% of site reported end points require CEC adjudication. Agreement remained very good during the period after algorithm derivation. CONCLUSIONS: An AAA-guided approach for end point adjudication was successfully developed and validated for the LAAO Registry. With this approach, the need for formal CEC adjudication was substantially reduced, with accuracy maintained above an 80% agreement threshold. After application specific validation, these methods could be applied to large registries and clinical trials to reduce the cost of event adjudication while preserving scientific validity.
Subject(s)
Atrial Appendage , Atrial Fibrillation , Ischemic Attack, Transient , Stroke , Humans , Aftercare , Patient Discharge , Ischemic Attack, Transient/complications , Registries , Stroke/prevention & control , Stroke/complications , Treatment Outcome , Atrial Fibrillation/complicationsABSTRACT
The Registry Assessment of Peripheral Devices (RAPID) convened a multidisciplinary group of stakeholders including clinicians, academicians, regulators and industry representatives to conduct an in-depth review of limitations associated with the data available to assess the paclitaxel mortality signal. Available studies were evaluated to identify strengths and limitations in the study design and data quality, which were translated to lessons learned to help guide the design, execution, and analyses of future studies. We suggest numerous actionable responses, such as the development and use of harmonized data points and outcomes in a consensus lean case report form. We advocate for reduction in missing data and efficient means for accrual of larger sample sizes in Peripheral arterial disease studies or use of supplemental datasets. Efforts to share lessons learned and working collaboratively to address such issues may improve future data in this device area and ultimately benefit patients. Condensed Abstract: Data sources evaluating paclitaxel-coated devices were evaluated to identify strengths and limitations in the study design and data quality, which were translated to lessons learned to help guide the design, execution, and analyses of future studies. We suggest numerous actionable responses, which we believe may improve future data in this device area and ultimately benefit patients.
Subject(s)
Angioplasty , Drug-Eluting Stents , Mortality , Paclitaxel/administration & dosage , Peripheral Arterial Disease/surgery , Tubulin Modulators/administration & dosage , Advisory Committees , Angioplasty, Balloon , Atherectomy , Common Data Elements , Data Accuracy , Data Collection , Femoral Artery/surgery , Humans , Meta-Analysis as Topic , Popliteal Artery , Randomized Controlled Trials as Topic , Reproducibility of Results , Risk Assessment , StentsABSTRACT
Identification and management of patients at high bleeding risk undergoing percutaneous coronary intervention are of major importance, but a lack of standardization in defining this population limits trial design, data interpretation, and clinical decision-making. The Academic Research Consortium for High Bleeding Risk (ARC-HBR) is a collaboration among leading research organizations, regulatory authorities, and physician-scientists from the United States, Asia, and Europe focusing on percutaneous coronary intervention-related bleeding. Two meetings of the 31-member consortium were held in Washington, DC, in April 2018 and in Paris, France, in October 2018. These meetings were organized by the Cardiovascular European Research Center on behalf of the ARC-HBR group and included representatives of the US Food and Drug Administration and the Japanese Pharmaceuticals and Medical Devices Agency, as well as observers from the pharmaceutical and medical device industries. A consensus definition of patients at high bleeding risk was developed that was based on review of the available evidence. The definition is intended to provide consistency in defining this population for clinical trials and to complement clinical decision-making and regulatory review. The proposed ARC-HBR consensus document represents the first pragmatic approach to a consistent definition of high bleeding risk in clinical trials evaluating the safety and effectiveness of devices and drug regimens for patients undergoing percutaneous coronary intervention.
Subject(s)
Congresses as Topic , Consensus , Hemorrhage/diagnosis , Hemorrhage/etiology , Percutaneous Coronary Intervention/adverse effects , Anticoagulants/administration & dosage , Anticoagulants/adverse effects , Congresses as Topic/trends , District of Columbia , Hemorrhage/prevention & control , Humans , Paris , Percutaneous Coronary Intervention/trends , Risk Assessment/methodsABSTRACT
Non-adherence has been well recognized for years to be a common issue that significantly impacts clinical outcomes and health care costs. Medication adherence is remarkably low even in the controlled environment of clinical trials where it has potentially complex major implications. Collection of non-adherence data diverge markedly among cardiovascular randomized trials and, even where collected, is rarely incorporated in the statistical analysis to test the consistency of the primary endpoint(s). The imprecision introduced by the inconsistent assessment of non-adherence in clinical trials might confound the estimate of the calculated efficacy of the study drug. Hence, clinical trials may not accurately answer the scientific question posed by regulators, who seek an accurate estimate of the true efficacy and safety of treatment, or the question posed by payers, who want a reliable estimate of the effectiveness of treatment in the marketplace after approval. The Non-adherence Academic Research Consortium is a collaboration among leading academic research organizations, representatives from the U.S. Food and Drug Administration and physician-scientists from the USA and Europe. One in-person meeting was held in Madrid, Spain, culminating in a document describing consensus recommendations for reporting, collecting, and analysing adherence endpoints across clinical trials. The adoption of these recommendations will afford robustness and consistency in the comparative safety and effectiveness evaluation of investigational drugs from early development to post-marketing approval studies. These principles may be useful for regulatory assessment, as well as for monitoring local and regional outcomes to guide quality improvement initiatives.
Subject(s)
Cardiovascular Agents/therapeutic use , Cardiovascular Diseases/drug therapy , Cardiovascular System/drug effects , Health Care Costs/statistics & numerical data , Medication Adherence/statistics & numerical data , Cardiovascular Agents/adverse effects , Cardiovascular Agents/economics , Case-Control Studies , Consensus , Decision Making , Humans , Intention to Treat Analysis/statistics & numerical data , Medication Adherence/psychology , Physicians/organization & administration , Placebos/administration & dosage , Risk Assessment , Safety , Societies, Scientific/organization & administration , Spain/epidemiology , Treatment Outcome , United States/epidemiology , United States Food and Drug Administration/organization & administrationABSTRACT
Identification and management of patients at high bleeding risk undergoing percutaneous coronary intervention are of major importance, but a lack of standardization in defining this population limits trial design, data interpretation, and clinical decision-making. The Academic Research Consortium for High Bleeding Risk (ARC-HBR) is a collaboration among leading research organizations, regulatory authorities, and physician-scientists from the United States, Asia, and Europe focusing on percutaneous coronary intervention-related bleeding. Two meetings of the 31-member consortium were held in Washington, DC, in April 2018 and in Paris, France, in October 2018. These meetings were organized by the Cardiovascular European Research Center on behalf of the ARC-HBR group and included representatives of the US Food and Drug Administration and the Japanese Pharmaceuticals and Medical Devices Agency, as well as observers from the pharmaceutical and medical device industries. A consensus definition of patients at high bleeding risk was developed that was based on review of the available evidence. The definition is intended to provide consistency in defining this population for clinical trials and to complement clinical decision-making and regulatory review. The proposed ARC-HBR consensus document represents the first pragmatic approach to a consistent definition of high bleeding risk in clinical trials evaluating the safety and effectiveness of devices and drug regimens for patients undergoing percutaneous coronary intervention.
Subject(s)
Drug-Eluting Stents/adverse effects , Dual Anti-Platelet Therapy/adverse effects , Hemorrhage/etiology , Percutaneous Coronary Intervention/adverse effects , Stents/adverse effects , Acute Coronary Syndrome/complications , Acute Coronary Syndrome/epidemiology , Acute Coronary Syndrome/physiopathology , Aged , Aged, 80 and over , Anemia/complications , Anemia/epidemiology , Anemia/physiopathology , Asia/epidemiology , Clinical Decision-Making , Clinical Trials as Topic , Consensus , Europe/epidemiology , Fibrosis/complications , Frailty/complications , Frailty/epidemiology , Frailty/physiopathology , Hemorrhage/epidemiology , Humans , Hypertension, Portal/epidemiology , Hypertension, Portal/physiopathology , Medication Adherence/statistics & numerical data , Metals , Percutaneous Coronary Intervention/instrumentation , Renal Insufficiency, Chronic/complications , Renal Insufficiency, Chronic/epidemiology , Renal Insufficiency, Chronic/physiopathology , Risk Assessment , Safety , Thrombocytopenia/complications , Thrombocytopenia/epidemiology , Thrombocytopenia/physiopathology , Treatment Outcome , United States/epidemiologyABSTRACT
The Academic Research Consortium (ARC)-2 initiative revisited the clinical and angiographic end point definitions in coronary device trials, proposed in 2007, to make them more suitable for use in clinical trials that include increasingly complex lesion and patient populations and incorporate novel devices such as bioresorbable vascular scaffolds. In addition, recommendations for the incorporation of patient-related outcomes in clinical trials are proposed. Academic Research Consortium-2 is a collaborative effort between academic research organizations in the United States and Europe, device manufacturers, and European, US, and Asian regulatory bodies. Several in-person meetings were held to discuss the changes that have occurred in the device landscape and in clinical trials and regulatory pathways in the last decade. The consensus-based end point definitions in this document are endorsed by the stakeholders of this document and strongly advocated for clinical trial purposes. This Academic Research Consortium-2 document provides further standardization of end point definitions for coronary device trials, incorporating advances in technology and knowledge. Their use will aid interpretation of trial outcomes and comparison among studies, thus facilitating the evaluation of the safety and effectiveness of these devices.
Subject(s)
Bioprosthesis/standards , Blood Vessel Prosthesis Implantation/standards , Blood Vessel Prosthesis/standards , Coronary Vessels/surgery , Prosthesis Design/standards , Stents/standards , Aortic Valve Stenosis , Clinical Trials as Topic , Consensus , HumansABSTRACT
This publication describes uniform definitions for cardiovascular and stroke outcomes developed by the Standardized Data Collection for Cardiovascular Trials Initiative and the US Food and Drug Administration (FDA). The FDA established the Standardized Data Collection for Cardiovascular Trials Initiative in 2009 to simplify the design and conduct of clinical trials intended to support marketing applications. The writing committee recognizes that these definitions may be used in other types of clinical trials and clinical care processes where appropriate. Use of these definitions at the FDA has enhanced the ability to aggregate data within and across medical product development programs, conduct meta-analyses to evaluate cardiovascular safety, integrate data from multiple trials, and compare effectiveness of drugs and devices. Further study is needed to determine whether prospective data collection using these common definitions improves the design, conduct, and interpretability of the results of clinical trials.
Subject(s)
Cardiovascular Diseases/diagnosis , Data Collection/standards , Endpoint Determination/standards , Stroke/diagnosis , Clinical Trials as Topic , Humans , United States , United States Food and Drug AdministrationSubject(s)
Angioplasty, Balloon , Paclitaxel/administration & dosage , Peripheral Arterial Disease/therapy , Stents , Angioplasty, Balloon/adverse effects , Angioplasty, Balloon/instrumentation , Atherosclerosis/therapy , Coated Materials, Biocompatible/adverse effects , Humans , Paclitaxel/adverse effectsABSTRACT
The Academic Research Consortium (ARC)-2 initiative revisited the clinical and angiographic end point definitions in coronary device trials, proposed in 2007, to make them more suitable for use in clinical trials that include increasingly complex lesion and patient populations and incorporate novel devices such as bioresorbable vascular scaffolds. In addition, recommendations for the incorporation of patient-related outcomes in clinical trials are proposed. Academic Research Consortium-2 is a collaborative effort between academic research organizations in the United States and Europe, device manufacturers, and European, US, and Asian regulatory bodies. Several in-person meetings were held to discuss the changes that have occurred in the device landscape and in clinical trials and regulatory pathways in the last decade. The consensus-based end point definitions in this document are endorsed by the stakeholders of this document and strongly advocated for clinical trial purposes. This Academic Research Consortium-2 document provides further standardization of end point definitions for coronary device trials, incorporating advances in technology and knowledge. Their use will aid interpretation of trial outcomes and comparison among studies, thus facilitating the evaluation of the safety and effectiveness of these devices.
Subject(s)
Clinical Trials as Topic , Coronary Artery Disease/therapy , Equipment and Supplies , Patient Reported Outcome Measures , Absorbable Implants , Asia , Europe , Humans , Outcome Assessment, Health Care , Stents , Tissue Scaffolds , United StatesSubject(s)
Device Approval , Foramen Ovale, Patent/therapy , Secondary Prevention/methods , Septal Occluder Device , Stroke/prevention & control , Foramen Ovale, Patent/complications , Foramen Ovale, Patent/drug therapy , Humans , Septal Occluder Device/adverse effects , Stroke/etiology , United States , United States Food and Drug AdministrationSubject(s)
Evidence-Based Medicine , Heart-Assist Devices , Shock, Cardiogenic/therapy , Cardiac Care Facilities/organization & administration , Consensus , Health Resources , Hospitals, High-Volume/standards , Hospitals, High-Volume/statistics & numerical data , Humans , Needs Assessment , Risk Assessment , Therapeutic EquipoiseABSTRACT
BACKGROUND/PURPOSE: There has been increasing emphasis on the development of new technology to mitigate unmet clinical needs in cardiovascular disease. This emphasis results in part from recognition that many devices, although being initially developed in the United States, were studied, and then eventually approved abroad before being returned to the U.S. for clinical application. The FDA (Food and Drug Administration) guidance document on Early Feasibility Studies (EFS) and then the 21st Century Cures Act from 2013 to 2016 focused on these issues. MATERIALS/METHODS: There are multiple components of medical device translational pathways to be considered in continuing to reach the goal of providing early access to safe and effective products to the U.S. POPULATION: This review article documents the various stages from early idea innovation to device design and iteration to clinical testing and then potential approval and application in the wide clinical practice of cardiovascular health care. RESULTS: The CDRH (Centers for Devices and Radiological Health) has focused on key components including EFS, Breakthrough Devices Program, Total Product Life Cycle, the Unique Device Identification Program, the establishment of a Digital Health Center of Excellence, and leveraging Collaborative Communities. Each of these initiatives focuses on improving the Medical Device Development Ecosystem. CONCLUSIONS: Major changes in device translational research have improved the device research climate in the United States. Goals remain including increased training and education for constituencies aspiring to work in the field of device development and regulation as part of a continuous health care learning system.
Subject(s)
Cardiovascular Diseases , Ecosystem , United States , Humans , Device Approval , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/therapy , United States Food and Drug Administration , Feasibility StudiesABSTRACT
In 2020, the NIH and FDA issued guidance documents that laid the foundation for human subject research during an unprecedented pandemic. To bridge these general considerations to actual applications in cardiovascular interventional device trials, the PAndemic Impact on INTErventional device ReSearch (PAIINTERS) Working Group was formed in early 2021 under the Predictable And Sustainable Implementation Of National CardioVascular Registries (PASSION CV Registries). The PAIINTER's Part I report, published by Rymer et al. [5], provided a comprehensive overview of the operational impact on interventional studies during the first year of the Pandemic. PAIINTERS Part II focused on potential statistical issues related to bias, variability, missing data, and study power when interventional studies may start and end in different pandemic phases. Importantly, the paper also offers practical mitigation strategies to adjust or minimize the impact for both SATs and RCTs, providing a valuable resource for researchers and professionals involved in cardiovascular clinical trials.
ABSTRACT
INTRODUCTION: Despite decades of research on risk-communication approaches, questions remain about the optimal methods for conveying risks for different outcomes across multiple time points, which can be necessary in applications such as discrete choice experiments (DCEs). We sought to compare the effects of 3 design factors: 1) separated versus integrated presentations of the risks for different outcomes, 2) use or omission of icon arrays, and 3) vertical versus horizontal orientation of the time dimension. METHODS: We conducted a randomized study among a demographically diverse sample of 2,242 US adults recruited from an online panel (mean age 59.8 y, s = 10.4 y; 21.9% African American) that compared risk-communication approaches that varied in the 3 factors noted above. The primary outcome was the number of correct responses to 12 multiple-choice questions asking survey respondents to identify specific numbers, contrast options to recognize dominance (larger v. smaller risks), and compute differences. We used linear regression to test the effects of the 3 design factors, controlling for health literacy, graph literacy, and numeracy. We also measured choice consistency in a subsequent DCE choice module. RESULTS: Mean comprehension varied significantly across versions (P < 0.001), with higher comprehension in the 3 versions that provided separated risk information for each risk. In the multivariable regression, separated risk presentation was associated with 0.58 more correct responses (P < 0.001; 95% confidence interval: 0.39, 0.77) compared with integrated risk information. Neither providing icon arrays nor using vertical versus horizontal time formats affected comprehension rates, although participant understanding did correlate with DCE choice consistency. CONCLUSIONS: In presentations of multiple risks over multiple time points, presenting risk information separately for each health outcome appears to increase understanding. HIGHLIGHTS: When conveying information about risks of different outcomes at multiple time points, separate presentations of single-outcome risks resulted in higher comprehension than presentations that combined risk information for different outcomes.We also observed benefits of presenting single-outcome risks separately among respondents with lower numeracy and graph literacy.Study participants who scored higher on risk understanding were more internally consistent in their responses to a discrete choice experiment.