How Long Should a Concussed Athlete be Sidelined?

What factors predict recovery time for an athlete who has suffered a concussion? A new study has some answers. As the Stanford University authors wrote, “Prognosticating recovery times for individual athletes with a concussion remains a challenge for health care providers. Several preinjury and postinjury factors have been proposed to be predictive of prolonged return-to-play times, but the data in this area are still sparse.”

The study, “Factors Associated With A Prolonged Time to Return to Play After a Concussion,” was published online on March 22, 2022 in The American Journal of Sports Medicine.

To identify risk factors which could delay return to play, the Stanford team collected concussion data for the period between September 2017 and August 2020 at a single National Collegiate Athletic Association Division I institution.

They looked at such preinjury risk factors as age, sex, sport, concussion history and past medical problems as well as postinjury risk factors such as initial and follow-up Sport Concussion Assessment Tool 5th Edition scores, vestibular evaluation findings and eye tracking results.

In total the team collected data for 159 athletes and 187 concussion cases. They found that preinjury factors associated with prolonged return to play times were:

1. a history of concussions (p = .015),
2. a history of migraines (p = .013), and
3. whether an athlete participated in an individual sport (p = .009).

Postinjury modifiers included:

1. the total number (p = .020) and severity (p = .023) of symptoms as well as,
2. abnormal Vestibular Ocular Motor Screening findings (p = .002).

Overall, there were 6 different symptoms—balance problems, difficulty concentrating, light sensitivity, drowsiness, fatigue/low energy, and difficulty remembering—that were significantly linked to prolonged return to play times.

“The study also found that the number and severity of symptoms were additive in a dose-dependent fashion. On multivariable analysis of all these factors, a history of concussions was found to be the most predictive of prolonged return to play times, while participation in an individual sport had the largest effect on recovery times,” the researchers wrote.

“Several preinjury and postinjury risk factors were identified as being correlated with prolonged recovery times. Many of these risk factors were also found to be additive in nature. This information provides clinicians with a valuable tool in prognosticating and estimating recovery times for athletes.”

“The study also revealed that athletes participating in individual sports had longer return to play times compared with athletes in team sports, which is a novel finding that requires further research.

The study authors include Eric X. Wang, M.D., Calvin E. Hwang, M.D., Jessica N. Nguyen, B.S., Nicole A. Segovia, MPH, Geoffrey D. Abrams, M.D., and Andrea Kussman, M.D., all of Stanford University School of Medicine.