Final Research Report

View this project's final research report.

Journal Citations

Article Highlight: More than 70,000 children in the United States have surgery each year to treat appendicitis. As reported in JAMA, a PCORI-funded study found that among children with uncomplicated appendicitis, nonsurgical treatment with antibiotics was successful in more than half of those patients, and compared with surgery initiated shortly after hospital admission, was associated with significantly fewer disability days. However, the results after one year did not meet the threshold success rate specified at the outset of the study.

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 expressed concern about the inconsistent acceptable threshold for establishing the efficacy of nonsurgical treatment; at one point in the report the researchers indicated that the threshold would be a 70 percent success rate for nonsurgical treatment, but in their conclusions the researchers wrote that nonsurgical treatment should be offered when the success rate was more than 50 percent. The researchers explained that in the absence of prior research establishing an acceptable threshold, they used the 70 percent success rate to interest surgeons in study participation. The researchers changed the conclusions to say that the data do not support a success rate that exceeds the preset 70 percent threshold.
  • The reviewers questioned the report’s description of success and failure at the one-year follow-up point in the study. The reviewers could not identify whether the researchers had included recurrent appendicitis within one year as part of the failure group even though it was more likely that an appendectomy between initial hospitalization and one year postdischarge was caused by recurrent appendicitis rather than the initial condition. The researchers confirmed that their definition of failure of nonoperative treatment at one year included initial in-hospital failures and suspected recurrent appendicitis. The researchers also added data to the report on negative appendectomy rate, which came from not identifying appendicitis at surgery by histology.
  • The reviewers noted that there was an unexpectedly high rate of loss to follow-up in the study and asked for what might explain this and whether the high rate of dropping out posed a risk for selection bias that might have affected the outcomes. The researchers said the high dropout rate may reflect the fact that appendicitis tends to be a time-limited disease and families participating in the study may have lost interest in participating further once the condition resolved. The researchers acknowledged that the high dropout rate could have introduced selection bias but said they believed the bias would equally affect both arms of the study.
  • A reviewer questioned whether it was necessary to have a nonrandomized trial design and asked the researchers to justify conducting a patient-choice trial in this population. The researchers acknowledged that other groups have performed randomized controlled trials even with patients who have treatment preferences, but said that in studies of children with appendicitis, less than 40 percent of eligible patients enrolled and those who enrolled disproportionately represented those who preferred a nonsurgical intervention, which was not offered outside the trial setting. The researchers felt that their pragmatic study design enrolled a broader population than otherwise would have participated and therefore leads to more useful estimates of the effectiveness of nonsurgical versus surgical treatment of appendicitis.

Conflict of Interest Disclosures

Project Information

Peter C. Minneci, MD, MHSc
The Research Institute at Nationwide Children's Hospital
Comparing the Effectiveness of Treating Pediatric Appendicitis with Antibiotics Versus Surgery

Key Dates

April 2016
February 2021

Study Registration Information


Has Results
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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: April 26, 2022