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WASHINGTON, DC – The Patient-Centered Outcomes Research Institute (PCORI) Board of Governors today approved a three-year, $14 million clinical trial designed to determine the best dose of aspirin to use to prevent heart attacks and strokes in people with heart disease.

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The study, called ADAPTABLE (Aspirin Dosing: A Patient-centric Trial Assessing Benefits and Long-term Effectiveness), will compare the benefits and harms of a low- and regular-strength daily dose of aspirin in patients diagnosed with heart disease. It is the first demonstration project to be conducted through PCORnet, the National Patient-Centered Clinical Research Network, which PCORI is developing to enhance the nation’s capacity to conduct much-needed health outcomes studies more quickly and efficiently, less expensively, and with greater potential impact than is now possible.

“Aspirin has been used for more than 40 years to prevent heart attacks and strokes in people diagnosed with heart disease, but the best dose has yet to be determined,” said PCORI Executive Director Joe Selby, MD, MPH. “We know aspirin can help, but we also know it can cause serious side effects, such as increased bleeding. So we’re very pleased to fund a study designed to answer this question. We’re especially pleased to do so as a way to demonstrate the power of PCORnet to recruit trial participants more efficiently and potentially generate results faster than would be possible otherwise.”

“We’re excited to be part of the first trial conducted through PCORnet,” said Adrian F. Hernandez, MD, MHS, Director of Outcomes and Health Services Research at the Duke Clinical Research Institute and the study’s co-principal investigator. “Heart disease is the leading cause of death for men and women in the United States. The results of this study, to be conducted in a variety of clinical settings, will help patients and those who care for them make better decisions about how aspirin therapy might be most helpful.”

An estimated 15.4 million Americans have coronary heart disease, most of whom take either a regular-strength (325 mg) or a low-dose (81 mg, or “baby aspirin”) dose daily as recommended by their clinicians. However, there is conflicting evidence about the potential benefits and risks of different doses. Regular-strength aspirin has been associated with a greater risk of bleeding in the gastrointestinal tract, but it’s unclear whether low-dose aspirin is both safer and as effective for patients with heart disease.

ADAPTABLE will be led by researchers at Duke and involve researchers, clinicians, and patients from six of PCORnet’s clinical data research networks (CDRNs), each made up of multiple large healthcare systems. The six are: Chicago Area Patient-Centered Outcomes Research Network (CAPriCORN), based at the Chicago Community Trust; Greater Plains Collaborative CDRN based at the University of Kansas Medical Center, Kansas City, Kansas; Louisiana CDRN, based at the Louisiana Public Health Institute, New Orleans; Mid-South CDRN, based at Vanderbilt University, Nashville; New York City CDRN, based at Weill Medical College of Cornell University; and PaTH: Towards a Learning Health System in the Mid-Atlantic Region, based at the University of Pittsburgh. In addition, the Health eHeart Patient- Powered Research Network, based at the University of California, San Francisco, will support the trial by providing a secure patient portal for data collection.

The trial will randomly assign 20,000 patients who have had a heart attack or have significant blockage of their coronary arteries to use a daily aspirin dose of 81 mg or 325 mg. Patients will be enrolled over 24 months, with a maximum follow-up of 30 months. The trial will be conducted in two stages, starting with a six-month protocol development and refinement phase. On the basis of a review of phase one activities, PCORI will decide whether the study will proceed to the implementation phase.

The study is designed to provide patients and providers detailed information about aspirin therapy given patients’ personal characteristics, conditions, and preferences. Researchers also will compare the effects of aspirin in certain patient populations based on gender, age, and racial- and ethnic-minority affiliation and in patients with and without diabetes or chronic kidney disease.

ADAPTABLE is a pragmatic trial, designed to ensure that its results reflect “real‐world” medical practice. Instead of being conducted in specialized research centers under optimized conditions, it will be conducted in a variety of clinical settings among a broad population and range of patients, healthcare systems, and practices. This is possible because the trial will use PCORnet’s vast “network of networks,” each of which engages a variety of patients, providers, and health systems working together to harness the power of health data for clinical research.

To facilitate more efficient recruitment, the trial aims to enroll patients via a unique patient-friendly web portal (Health eHeart) and use a patient-friendly electronic informed consent and information process. Paper-based consent material will also be available as needed.

ADAPTABLE will be the first of several demonstration projects designed to test PCORnet’s capacity to conduct comparative effectiveness and other types of research. PCORI invested $93.5 million in December 2013 to support the development and expansion of 29 individual health data networks that make up PCORnet. These include 11 CDRNs, based in large health systems, and 18 Patient-Powered Research Networks (PPRNs), based in a range of patient groups. PCORI plans to offer up to an additional $150.7 million to support further development of PCORnet.

The award to support the aspirin trial was approved by PCORI’s Board pending completion of a business programmatic review by PCORI staff and issuance of a formal award contract.

About PCORnet

PCORnet, the National Patient-Centered Clinical Research Network, is an innovative initiative of the Patient-Centered Outcomes Research Institute (PCORI). The goal of PCORnet is to improve the nation’s capacity to conduct comparative clinical effectiveness research efficiently by creating a large, highly representative network for conducting clinical outcomes research that directly involves patients in the development and execution of the research. More information is available at www.pcornet.org.


The Patient-Centered Outcomes Research Institute (PCORI) is the nation’s leading funder of patient-centered comparative clinical effectiveness research (CER). By comparing two or more health or healthcare approaches, CER generates evidence that helps people make better-informed decisions and improves healthcare delivery and outcomes. PCORI takes a holistic approach to its work, ensuring that patients and other health decision makers are engaged as partners throughout the research process, supporting dissemination and implementation of results in practice and strengthening clinical research infrastructure to advance patient-centered CER. PCORI is an independent, non-profit organization authorized by Congress.

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