Results Summary

What was the research about?

Antibiotics are the most commonly prescribed medicine in children. Narrow-spectrum antibiotics target a few types of bacteria. Broad-spectrum antibiotics target many types of bacteria. Both types work well to treat infections. But using broad-spectrum antibiotics when they’re not needed can create antibiotic-resistant bacteria that are hard to treat. They may also have side effects, such as diarrhea or rash.

In this study, the research team compared narrow-spectrum and broad-spectrum antibiotics to treat ear, sinus, and throat infections in children.

What were the results?

  • Treating infections. Narrow-spectrum antibiotics worked as well as broad-spectrum antibiotics to treat infections. Symptoms improved the same amount in three days.
  • Side effects. Children who took narrow-spectrum antibiotics had fewer side effects than those who took broad-spectrum antibiotics.
  • Quality of life. There were no differences in quality of life between children who took broad- or narrow-spectrum antibiotics.

What did the research team do?

The research team did two studies. In both studies, children were ages 6 months to 12 years.

In the first, the research team looked at health records for 30,159 children who used broad- or narrow-spectrum antibiotics to treat ear, sinus, or throat infections. Of the children, 63 percent were white, 16 percent were mixed or another race, 12 percent were black, and 8 percent were Hispanic. The average age was 5, and 52 percent were boys. The team looked at how often treatment worked and whether patients had side effects in the month after diagnosis.

The second study included 2,472 children. All children had an ear, sinus, or throat infection. The research team interviewed parents and children about quality of life, how long symptoms lasted, and side effects after the children got antibiotics. Of the children, 59 percent were white, 23 percent were black, 8 percent were another race, and 9 percent were Hispanic. The average age was 5, and 52 percent were boys. All were patients at one of 31 children’s clinics in Pennsylvania or New Jersey.

Children, parents, and physicians helped plan and conduct the study.

What were the limits of the study?

Some children in the study may have had infections caused by viruses. Because antibiotics don’t treat viruses, the results could differ if only children with infections caused by bacteria were in the study.

Future research could study the two types of antibiotics in children with confirmed infections caused by bacteria.

How can people use the results?

Doctors and parents can use these results to make decisions about the type of antibiotic to use.

Final Research Report

View this project's final research report.

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 confirms that the research has followed PCORI’s Methodology Standards. During peer review, experts who were not members of the research team read a draft report of the research. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. Reviewers do not 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 how the research team analyzed its results or reported its conclusions. Learn more about PCORI’s peer-review process here.

In response to peer review, the PI made changes including

  • Adding details about the sensitivity analyses that the author conducted, as these were mentioned in the Methodology Standards checklist but initially not described in the text of the report.
  • Addressing reviewer questions about whether the statistically significant difference found on the PedsQL (pediatric quality of life measure) was clinically meaningful. The researchers added cautions about interpreting the results from this measure because the measure was not originally designed to assess child quality of life following acute respiratory infection, and because the small differences between patients treated with narrow- and broad-spectrum antibiotics were unlikely to be clinically meaningful.
  • Noting an additional limitation of the study: the analyses did not account for baseline PedsQL measures and any chronic conditions.
  • Explaining that the sampling strategies were different for the patient-centered outcomes cohort and the clinician-centered outcomes cohort. This was because the researchers stratified the recruitment of patients for patient-centered outcomes cohort by diagnosis and antibiotic type, and oversampled certain strata to insure adequate numbers to conduct analyses. This was unnecessary for the inclusion of clinicians in the clinician-centered outcomes cohort.

Conflict of Interest Disclosures

Project Information

Jeffrey Gerber, MD, PhD
The Children's Hospital of Philadelphia
Comparative Effectiveness of Broad- versus Narrow-Spectrum Antibiotics for Acute Respiratory Tract Infections in Children

Key Dates

September 2013
June 2018

Study Registration Information


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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
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Last updated: January 20, 2023