Association Between Sleep Duration and Recovery Trajectories After a Concussion in United States Service Academy Cadets and Midshipmen

BACKGROUND: Failing to obtain adequate sleep has been associated previously with greater postconcussion symptom burdens and protracted neurocognitive recovery. Sleep-related symptoms may delay concussion recovery. Active military populations frequently obtain less sleep than is recommended.

HYPOTHESIS: Cadets and midshipmen who reported less sleep experienced prolonged recovery trajectories postconcussion.

STUDY DESIGN: Retrospective observational cohort.

LEVEL OF EVIDENCE: Level 4.

METHODS: Study participants were military service academy members from 4 United States (US) Service Academies. The primary outcome of interest was the association between sleep duration recorded during the initial concussion injury assessment and time to unrestricted return to activity (URTA). Participants were divided into groups based on sleep duration (<6, ≥6 to <7, ≥7 to ≤8, >8 hours). Kaplan-Meier survival estimates were calculated for different recovery milestones, including time (days) from initial injury to clearance for URTA, and from initiation of a graduated return to activity (GRTA) protocol and URTA clearance. Univariate and multivariable Cox proportional-hazards regression models were used to estimate hazard ratios and 95% CI for recovery by sleep group.

RESULTS: During the study period, 1339 participants (39% female; age, 19.4 ± 1.5 years; height, 175.1 ± 14.8 cm; weight, 74.1 ± 15.2 kg) sustained a concussion. Participants reporting <6 hours of sleep at their initial injury evaluation took 19% longer to reach URTA when compared with participants reporting ≥7 hours to ≤8 hours of sleep. These participants also displayed GRTA protocol durations that were 18% longer than those reporting ≥7 hours to ≤8 hours of sleep.

CONCLUSION: Sleep duration influenced postconcussion recovery trajectories. Participants who reported <6 hours of sleep took significantly longer to reach URTA.

CLINICAL RELEVANCE: The amount of sleep obtained before a concussion and during a postconcussion recovery trajectory may impact the total recovery duration.