Table 6. .

Summary of Studies Evaluating Outcomes After the Use of a Graded Return-to-Activity Progression Continued on Next Page

Study	Design	Patients	Intervention	Outcomes	Main Findings	Conclusions	Level of Evidencea
Chermann et al57 (2014)	Prospective cohort	35 Patients (30 males, 5 females; 23.1 ± 5.5 y), all rugby athletes	Followed standardized management protocol based on Zurich guidelines that included immediate removal, imaging, cognitive assessment, and return-to-exercise progression before clearance	SymptomsDelay before returning to sportRecurrent (repeat) concussion	Median of 6 d until symptoms resolved (females: 15 d, range = 10–210 d; males: 4 d, range = 0.5–270 d)Mean return to sport at 21 d (range = 7−45 d)Only 2 athletes sustained repeat concussions; both had concussion history, and initial concussion was grade 3 injury (Cantu revised scale)	Use of structured protocol based on Zurich guidelines successful in returning patients to activity with minimal risk of repeat injury	3
Darling et al56 (2014)	Retrospective chart review and follow-up	117 Patients (15.5 ± 1.6 y, 75% male) with clinician-diagnosed concussion; 41.2% football players and 25% ice hockey players	Evaluation of BCTT with the Zurich guidelines	Neurocognitive function (Automated Neuropsychological Assessment Metrics or ImPACT)Symptom severity (SCAT2)Physiologic recovery (BCTT)	On average, patients took 16 ± 15 d (range = 0–61 d) from time of concussion until reporting to be asymptomaticFemale athletes took longer than male athletes (22 ± 18 d versus 14 ± 13 d) to be asymptomaticTime from concussion to physiologic recovery longer (24 ± 19 d, range = 3–108 d) with minimal difference between sexes	The BCTT in combination with Zurich guidelines seemed to be safe and successful for returning patients to activity.	4
Echlin et al55 (2010)	Prospective, cohort	15 Patients aged 18.2 ± 1.2 y, all ice hockey players	Evaluation of duration of medical restriction after physician-observed and -diagnosed concussion following Zurich return-to-play guidelines	Duration of medical restrictionNeurocognitive function (ImPACT and SCAT2)	Average time interval before clinical recovery and return to hockey of 12.8 ± 7.0 d (range = 7–29 d)5 of 17 Patients (29%) sustained repeat injury with mean interval between injuries of 78.6 ± 39.8 d	Return-to-activity decisions augmented by ImPACT and SCAT2 results and fell in line with Zurich guidelines that clinical decisions should be based on multifactorial input	3
McCrea et al58 (2009)	Prospective, nonrandomized cohort	Combined data from 3 large datasets (n = 16 624 player seasons)N = 562	No interventionGroup assignment determined by SFWP or no SFWP	Extent to which SFWP was implementedRecurrent (repeat) concussionClinical outcome defined by scores on the Graded Symptom Checklist, BESS, and Standardized Assessment of Concussion	60.3% of Patients had SFWPNo differences between groups for demographics or baseline outcome scoresNo differences between groups for duration of symptoms or for Graded Symptom Checklist or Standardized Assessment of Concussion score at time of injury or 2 to 3 h after injuryPatients in the no-SFWP group returned to sport participation 1.22 d (95% confidence interval = –0.89, –1.55 d) before reaching full symptom resolution and 7.10 d (95% confidence interval = 5.67, 8.53 d) earlier than the SFWP group.	An SFWP did not influence recovery from concussion or decrease risk of repeat injury.	3

Abbreviations: BCTT, Buffalo Concussion Treadmill Test; BESS, Balance Error Scoring System; ImPACT, Immediate Post-Concussion Assessment and Cognitive Test; SAC, Standardized Assessment of Concussion; SCAT2, Sport Concussion Assessment Tool-2; SFWP, symptom-free waiting period.

^aLevels of evidence are based on the Oxford Centre for Evidence-Based Medicine taxonomy.¹⁷