Assessments of risk of bias in included studies, according to the NOS
| Selection | Comparability | Outcome | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Author, date | Representativeness of exposed cohorts† | Selection of nonexposed cohort‡ | Ascertainment of exposure§ | Demonstration outcome of interest not present study start¶ | Comparability of cohorts: assessment tool‡ | Comparability of cohorts: other factors‡ | Assessment of outcome | Follow-up long enough for outcomes to occur** | Adequacy of follow-up of cohorts** | Potential maximum score | Actual score |
| Studies providing complete preconcussion or preconcussion and postconcussion data | |||||||||||
| Benedict, 2015 | 0 | * | * | * | N/A | N/A | 4 | 3 | |||
| Glaviano, 2015 | 0 | * | * | * | N/A | N/A | 4 | 3 | |||
| Hänninen, 2015 | * | * | * | * | N/A | N/A | 4 | 4 | |||
| Jinguji, 2012 | 0 | * | * | * | N/A | N/A | 4 | 3 | |||
| Mayfield, 2013 | * | * | * | * | * | * | 6 | 6 | |||
| Putukian, 2015 | 0 | * | * | * | * | * | 6 | 5 | |||
| Snyder, 2014 | * | * | * | * | N/A | N/A | 4 | 4 | |||
| Valovich McLeod, 2012 | * | * | * | * | N/A | N/A | 4 | 4 | |||
| Weber, 2013 | * | * | * | * | N/A | N/A | 4 | 4 | |||
| Zimmer, 2015 | * | * | * | * | N/A | N/A | 4 | 4 | |||
| Studies presenting partial data | |||||||||||
| Baker, 2015 | 0 | * | 0 | 0 | N/A | N/A | 4 | 1 | |||
| Carson, 2014 | 0 | * | 0 | * | 0 | 0 | 6 | 2 | |||
| Echlin, 2010 | 0 | * | * | * | * | * | 6 | 5 | |||
| Galetta, 2013 | 0 | * | 0 | 0 | * | 0 | 6 | 2 | |||
| Galetta, 2015 | * | * | 0 | * | * | * | 6 | 5 | |||
| Jennings, 2015 | * | * | * | 0 | N/A | N/A | 4 | 3 | |||
| King, 2012 | 0 | * | * | * | * | * | 6 | 5 | |||
| King, 2013 | 0 | * | * | * | * | * | 6 | 5 | |||
| King, 2015 | 0 | * | 0 | * | N/A | N/A | 4 | 2 | |||
| Miller, 2015 | 0 | * | * | * | N/A | N/A | 4 | 3 | |||
| Mrazik, 2013 | 0 | * | * | * | N/A | N/A | 4 | 3 | |||
N/A=study performed a baseline assessment and planned no follow-up SCAT assessment, or follow-up data are not related to concussion (Jennings et al37 compared preseason to postseason SAC and BESS scores, Mrazik et al47 compared players before and after the 20 m Leger shuttle-run test and Weber (2013) compared wrestlers at baseline to postpractice when they were dehydrated).
†Is the exposed (preteenaged to high school population with active sports participation assessed with SCAT2 or SCAT3 tools) cohort truly or somewhat representative of young athletes who suffer sports-related concussions/are exposed to sports-related concussions?
‡Because this review identified no studies with interventions, none included a hemi-cohort exposed to an intervention and a hemi-cohort which was the control.
§Exposure is defined as a competitive athlete who has received a complete or partial SCAT2 or SCAT3 assessment.
¶Players were specifically asked if they had a recent concussion before the SCAT was administered; or if they were in a concussed group whether they also had a more recent concussion before testing.
** Single asterisk=complete follow-up, OR if participants lost to follow-up were unlikely to introduce bias (according to NOS instructions).
BESS, Balance Error Scoring System; NOS, Newcastle-Ottawa Scale; SAC, Standardised Assessment of Concussion; SCAT, Sport Concussion Assessment Tool; SCAT, Sport Concussion Assessment Tool.