Study Examines Whether Concussed Athletes Are More Susceptible to Second Concussion

Jun 7, 2019

A new study from Children’s Hospital of Philadelphia’s (CHOP) Center for Injury Research and Prevention (CIRP) and the Centers for Disease Control and Prevention (CDC) finds that one in six children aged 5 to 15 who has a concussion will go on to experience a repeat concussion within two years. Several characteristics of the initial concussion predict an elevated risk of subsequent concussions, including an increased number of symptoms and longer recovery time.
The findings were recently published in The Journal of Pediatrics.
Researchers identified, through review of electronic health records (EHRs), 536 children aged 5 through 15 who had an initial visit for a concussion at a CHOP location between July 1, 2012 and June 30, 2013, and reviewed their EHR for a two-year follow-up period. They found that eight percent of patients were diagnosed with a second concussion within the first year, and 16 percent had a second concussion within two years, including three percent who were diagnosed with two additional concussions. The risk of repeat concussion among 12- to 15-year-olds was almost twice as high as that of 9- to 11 year-olds, but this increased risk may simply be related to their increased exposure to sports and recreational activities.
“Knowing a child’s increased risk for repeat concussions can help families make better decisions about their child’s health,” says study author Christina Master, MD, co-lead for CIRP’s concussion research program and a sports medicine pediatrician at CHOP. “We know that having a lot of symptoms or a long recovery time from your initial concussion are associated with a subsequent concussion within a couple of years. By looking at the number of symptoms and length of recovery, clinicians can give families data on which to make informed decisions about future risk.
A recovery course of more than 28 days correlated to a 65 percent increased risk of repeat concussion compared to patients with a recovery of less than seven days. [This doesn’t make sense. Shouldn’t risk decrease with longer recovery?] Patients who experienced more than 10 symptoms had twice the risk of repeated injury compared to patients with less than two symptoms. The risk of concussion did not vary by how patients got their initial concussion, suggesting that all concussions, regardless of cause, contribute to an individual’s overall burden of concussion and risk of subsequent injury.
“This is one of the first studies to quantify the risk of a subsequent injury given a first concussion,” said Dr. Matt Breiding of the CDC. “We hope that clinicians will pay particular attention to these findings since repeat concussions can have real consequences for a young person’s health and development. The results of this study can aid a clinician in discussing the risk of further injury with patients and their parents.”
E. Curry, PhD, MPH, et. al. “Risk of Repeat Concussion Among Patients with a Concussion at a Pediatric Care Network.” Journal of Pediatrics. Online May 14, 2019. DOI:


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