Results Summary

What was the research about?

Strokes occur when blood vessels to the brain leak or become blocked, cutting off the supply of oxygen to the brain. People who have had a stroke may be at risk of having another one. High cholesterol or an irregular heartbeat, called atrial fibrillation, can increase risk for another stroke. Different types of medicine may help reduce this risk.

The research team looked at how well different types of medicine helped people avoid returning to the hospital or prevented major heart problems or another stroke. The team looked at

  • Blood thinners. Warfarin is a common blood thinner that keeps blood clots from forming. The team looked at how well warfarin works compared with no medicine in people with atrial fibrillation. The team also compared warfarin with newer blood thinners called NOACs.
  • Statins. Statins are medicines that help lower cholesterol levels in the blood. Statins can reduce the risk of stroke and heart attack. They can also cause side effects, such as muscle aches. The research team compared patients who received different levels of statins with patients who received no statins.

What were the results?

Blood thinners. Patients with atrial fibrillation who received warfarin had a lower risk for major heart problems and spent more days at home than those who received no medicine. Compared with patients who received warfarin, patients who received NOACs had a lower risk for major heart problems and spent more days at home.

Statins. Patients who received statins had a lower risk for major heart problems and spent more days at home than those who received no statins. Patients receiving either a high-dose or low-dose statin had similar risk for major heart problems and a similar number of days spent a home.

Who was in the study?

The research team reviewed health and Medicare records for 12,552 patients in the blood thinner studies and 77,468 patients in the statin studies. All patients had a stroke and were ages 65 and older. Patients in the blood thinner studies had atrial fibrillation. Patients in the statin studies were not taking statins before they had a stroke.

What did the research team do?

The research team looked at patients’ health and Medicare records for two years after patients were treated for a stroke.

Patients, caregivers, healthcare providers, and agencies provided input on the study’s design. Patients also provided input on enrollment, analysis, and sharing results.

What were the limits of the study?

Medicare records may not capture all medicines and treatments that patients receive. Also, the research team couldn’t tell if patients took their medicines. If patients weren’t taking their medicines, the study’s results might be different. The team only looked at two years of records. Differences in long-term effects of medicines may not show up until after two years.

Future research could look at patients’ health records for longer than two years.

How can people use the results?

Patients and their doctors can use these results when considering treatments after a stroke.

Final Research Report

View this project's final research report.

Journal Citations

Article Highlight: This study compared outcomes of older adults who have atrial fibrillation and have had a stroke. In a new paper published in JAMA Neurology, the research team reports that patients who were prescribed direct oral anticoagulants when discharged from the hospital following a stroke had relatively better outcomes—including more days at home and fewer adverse events—than patients prescribed the blood thinner warfarin. This reinforces findings from prior research on the subject.

Peer-Review Summary

Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.

The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments. 

Peer reviewers commented and the researchers made changes or provided responses. Those comments and responses included the following:

  • The reviewers noted that aim 3 of the study, involving the development and testing of a novel decision aid for stroke survivors, originally was not reported in the draft report. The researchers added information about the decision aid they created in the methods, results, and discussion sections of the report.
  • The reviewers were unclear on how the retrospective and prospective study cohorts aligned with the aims, and how the two populations differed in characteristics and in what outcomes the researchers measured. The researchers explained that they designed the prospective cohort to evaluate the patient-reported outcomes that are typically not available in registry data. They noted that depression and antidepressant use are likely to affect these outcomes, so these factors were specifically examined in the prospective group. Similarly, they investigated statin and oral anticoagulant use in the retrospective cohort because subsets of the stroke survivor population used those medications.. Therefore, they needed the larger sample size that the registry-based population provided in order to detect a meaningful effect.
  • The reviewers wondered how clinically meaningful some of the observed associations were, since the study’s large sample size allowed for differences of relatively small magnitude to be statistically significant. The researchers agreed this was a good point and explained that they used methods to help minimize false positives and overly strong conclusions based on multiple comparisons. They added that they felt that differences they described, like a 9-13 percent reduction in major adverse cardiovascular events, were clinically meaningful. 
  • The reviewers asked for more information on the background of patient coinvestigators and how the researchers  selected them. The researchers said they used American Heart Association resources to identify stroke survivors within their network of volunteers. All patient coinvestigators turned out to be women who had strokes between their 20s and their 50s. Despite the homogeneity in this group, these patient coinvestigators, as active members of stroke support groups, tried to speak from the perspective of a wide range of stroke survivors rather than only from personal experience.
  • The reviewers requested more detail on the study’s use of focus groups, their demographic makeup, and the methods used to survey them. The researchers said that the focus groups were a small part of the project and did not contribute to the project’s aims, so the researchers did not formally record the information the reviewers requested. The researchers explained that their goals for the focus groups were to confirm that the project’s aims were meaningful to a wide range of stroke patients and to inform subgroup analyses.

Conflict of Interest Disclosures

Project Information

Adrian F. Hernandez, MD, MHS
Duke University
Patient-Centered Research into Outcomes Stroke Patients Prefer and Effectiveness Research (PROSPER)

Key Dates

September 2013
March 2020

Study Registration Information


Has Results
Award Type
Health Conditions Health Conditions These are the broad terms we use to categorize our funded research studies; specific diseases or conditions are included within the appropriate larger category. Note: not all of our funded projects focus on a single disease or condition; some touch on multiple diseases or conditions, research methods, or broader health system interventions. Such projects won’t be listed by a primary disease/condition and so won’t appear if you use this filter tool to find them. View Glossary
Populations Populations PCORI is interested in research that seeks to better understand how different clinical and health system options work for different people. These populations are frequently studied in our portfolio or identified as being of interest by our stakeholders. View Glossary
Intervention Strategy Intervention Strategies PCORI funds comparative clinical effectiveness research (CER) studies that compare two or more options or approaches to health care, or that compare different ways of delivering or receiving care. View Glossary
State State The state where the project originates, or where the primary institution or organization is located. View Glossary
Last updated: March 14, 2024