This research project is in progress. PCORI will post the research findings on this page within 90 days after the results are final. In the meantime, results have been published in peer-reviewed journals, as listed below.

What is the research about?

Researchers can use a study design called an N-of-1 trial to learn how well a treatment works for a specific patient. These trials include only one patient and compare the time when a patient is getting treatment to the time when he or she is not.  Researchers can also combine multiple N-of-1 trials to look at treatment effects across patients.

Although N-of-1 trials show promise, researchers rarely use them. Many researchers aren’t familiar with the methods. Also, researchers don’t have an easy way to collect and analyze data from these studies.

In this study, the research team is tailoring a mobile app called Eureka and using it to conduct N-of-1 trials. Eureka allows the research team to collect and track patient data and view results from these trials. The trials focus on inflammatory bowel disease, or IBD, in children and atrial fibrillation, or AF, in adults. The team chose IBD and AF because N-of-1 studies are most useful when symptoms and response to treatment vary widely across patients, as is the case with IBD and AF.

This study has three parts:

In Part 1, the research team is using a series of N-of-1 trials to see how well the specific carbohydrate diet, or SCD, reduces symptoms and inflammation in children with IBD compared with a modified SCD.

In Part 2, the team wants to know if using an N-of-1 study design helps patients identify and avoid AF triggers and episodes compared with tracking symptoms without the structure of an N-of-1 trial.

In Part 3, the team is examining study participants’ views on the feasibility and acceptability of N-of-1 designs.

Who can this research help?

Results from this research may help patients and clinicians considering management options for IBD and AF. This study may also help researchers learn more about the feasibility of using N-of-1 trials for comparing treatments.

What is the research team doing?

The research team is recruiting 120 children with IBD and 478 adults with AF. 

In Part 1 of the study, participants with IBD are beginning the trial on their usual diet. They then alternate between the SCD and a modified SCD for 32 weeks. Using the Eureka app, patients report daily on stool frequency and weekly on pain and other symptoms. They also mail stool samples for analysis throughout the study. At the end of the N-of-1 study, patients receive results about the diet’s effects on their symptoms and inflammation. The research team is also combining results of individual N-of-1 trials to see the effects across patients.  

In Part 2, the research team is assigning patients by chance to one of two groups. All patients receive text reminders to track their AF episodes, triggers, mood, and sleep quality in the Eureka app. Patients in both groups can also see a summary of their symptoms and triggers over time. One group follows the N-of-1 design. In that group, patients choose one thing they think triggers AF, like caffeine. Then they track what happens when they have caffeine or don’t. At the end of the study, they receive a report on whether that trigger is related to their AF. In the second group, patients track symptoms in the app without this design. After 3 months, the team is comparing quality of life and AF severity for patients in the two groups.

In Part 3, the research team is interviewing patients who completed N-of-1 trials as part of the IBD or AF study to understand their experiences with N-of-1 trials.

Patients with AF and IBD, parents of children with IBD, clinicians, and researchers helped develop and prioritize the research questions. The research team also includes patients with AF and IBD and parents of children with IBD, who are helping to plan and carry out the study.

Research methods at a glance