Our study evaluated for differences in Child SCAT5 scores, and their subsequent diagnostic properties, among concussed and non-concussed middle school children on the day that they were evaluated for a suspected concussion. Our findings demonstrate that concussed children endorse a greater number and severity of symptoms and suggest that the symptom evaluation is the most effective component of the Child SCAT5 for differentiating between concussed and non-concussed children on the same day as a suspected concussion. The concussed children also committed significantly more errors on the mBESS than the non-concussed children, however, the magnitude of these differences were relatively small as supported by the effect sizes. Our data suggests that the SAC-C is the least meaningful component of the Child SCAT5 as no significant differences were observed between the concussed and non-concussed children which resulted in poor diagnostic accuracy values. Overall, our study reinforces the importance of the symptom evaluation as an integral part of the clinical assessment of children on the same day as a suspected concussion.
Self-reported symptomology has been a cornerstone of concussion evaluation and remains the key component for informing clinical judgement. Our data demonstrates that concussed middle school children endorse a significantly greater number and severity of symptoms than children who are not diagnosed with a concussion. Specifically, the concussed children in our sample endorsed nearly double the number of symptoms (8.0±5.50 vs. 3.7±3.97) and symptom severity (12.1±10.5 vs. 12.1±10.9) as compared to the non-concussed children. Previous literature has demonstrated that concussed children evaluated in the emergency department using the Child SCAT3 endorsed significantly more symptoms and greater severity than non-concussed children, which is alignment with our results. Our findings also align well with previous literature that have reported elevated endorsement and severity of symptoms in older athletic populations (e.g., high school, collegiate) following a diagnosed concussion as compared to preinjury (baseline) data or matched comparisons.[23, 63, 64] We did not incorporate baseline assessments or matched comparisons, thus, we encourage future research to investigate these differences in symptom reporting of middle school children following a suspected concussion.
Our study also observed that concussed children committed significantly more errors in two stances (double leg, single leg) of the mBESS and had significantly higher mBESS total scores as compared to the non-concussed children. Furthermore, our mBESS total scores for the concussed children (7.8±4.53 errors) were slightly elevated compared to normative reference values for this population (5.0±3.7 errors). However, the small effect sizes (r=0.23–0.26) calculated for the concussed versus non-concussed comparisons suggest that the differences may not be clinically meaningful. Findings from our sample of middle school children align well with extensive literature that have reported that concussed high school and collegiate athletes perform worse on the BESS than non-concussed athletes.[22, 23, 63, 64, 66, 67] Collectively, our findings and those of previous literature that assessed older athletic populations suggest that balance assessment following a suspected concussion may elicit subtle deficits to inform clinical diagnosis and management.
The concussed children in our study did not perform significantly different on any component of the SAC-C as compared to the non-concussed children on the same day as the suspected concussion. The SAC-C composite scores were also not significantly different between the concussed and non-concussed groups in our sample and the values for each group align within the “broadly normal” interpretation of normative reference values for this population. The lack of significant findings between the concussed and non-concussed groups is different than previous literature that evaluated older athletic populations.[22, 23, 63, 64, 66, 67] Possible rationales for the lack of significant differences in SAC-C scores include discrepancies in the age of the participants in our study (middle school children) as compared to those of previous literature study populations (high school or collegiate athletes) and different ranges of composite scores for the SAC (range=0-25) and SAC-C (range=0-26).
To our knowledge, our study is the first to provide evidence of the diagnostic properties of the Child SCAT5 in the population for which it was designed. The total number and severity of endorsed symptoms were found to have the highest levels of diagnostic accuracy (AUC=0.76–0.77) and sensitivity (Sn=0.79–0.88) of the Child SCAT5 scores. Based on the calculated cutoff scores, children who endorse less than four symptoms or report a severity less than six points on the same day as the suspected concussion were less likely (-LR=0.22–0.31) to be diagnosed with a concussion. As mentioned previously, it is important to note that none of the children assessed for a suspected concussion were permitted to return to sport participation on the same day as the assessment regardless of their Child SCAT5 scores. This is in alignment with the recommendations from the leading international consensus group on concussion in sport, position statements from several governing bodies,[12–14] and the legal requirements of state laws.
The highest positive predictive values and likelihood ratios were observed for interpretation of the double leg stance of the mBESS followed by the delayed recall domain of the SAC-C. However, inordinately low thresholds for a positive test result (e.g., diagnosed concussion) for the double leg stance of the mBESS (≤1 error) and the delayed recall domain of the SAC-C (≤1 point) yielded high specificity values (Sp=0.98–1.00) which artificially elevated the calculated positive predictive values and likelihood ratios. Therefore, we caution healthcare professionals from independent interpretation of the double leg stance of the mBESS or the delayed recall domain of the SAC-C in their clinical decision-making at this time. Future research is warranted to validate our findings related to the diagnostic properties of the individual components (symptom evaluation, SAC-C, mBESS) of the Child SCAT5 in an independent sample of children on the same day as a suspected concussion.
The calculated diagnostic properties of the Child SCAT5 scores in our study align with those reported for previous iterations of the SCAT and the Child SCAT3.[23, 44, 63, 67] More specifically, the values of sensitivity, specificity, and diagnostic accuracy observed in our study are similar to those calculated for the individual components of the SCAT for the assessment of older athletes.[23, 63, 67] A similar methodology as our study has been implemented to evaluate for differences and assess the diagnostic properties of Child SCAT3 scores among children who were evaluated for a suspected concussion in the emergency department. The authors of this prior study reported similar diagnostic accuracy values for Child SCAT3 scores to those observed in our study which utilized the Child SCAT5. Overall, our findings support those of previous literature[23, 44, 63, 67] which suggest that the symptom evaluation has the best combination of diagnostic properties and is the most effective component of the Child SCAT for differentiating between concussed and non-concussed children.
Healthcare professionals in direct access settings (e.g., emergency department, outpatient clinics) may be the first to evaluate a child following a suspected concussion and likely will not have access to preinjury (baseline) scores for comparison. It is vital that healthcare professionals in direct access settings are equipped with age-appropriate assessment tools that can effectively differentiate between those who are and are not concussed in order to appropriately inform patient care. Our findings reinforce the importance of the symptom evaluation of the Child SCAT5 and suggest that healthcare professionals can be confident in the clinical interpretation of acute symptom reporting of children following a suspected concussion. The poorer diagnostic accuracy of the SAC-C and mBESS highlights the inability of these assessments to adequately differentiate between concussed and non-concussed children which limits their clinical utility on the same day as a suspected concussion. Future research should investigate alternative assessment tools (e.g., tandem gait test) or strategies (e.g., the dual task paradigm) for the acute evaluation of children following a suspected concussion. Findings from this future research may provide additional objective data to assist in the evaluation of children with a suspected concussion.
We recognize that our study is not without limitations. All of the children in our study were participating in school-sanctioned sports at middle schools within a single county in the northern Virginia which limits our generalizability. However, the middle school student population in our study has a unique socio-demographic profile including students of diverse racial backgrounds (e.g., 36.7% Hispanic, 27.8% White/Caucasian, 20.7% Black/African-American) and high academic achievement (e.g., less than a 2% course failure rate overall). Another limitation is the variability in the time between the removal from sport and the concussion evaluation, however, all participants were evaluated on the same day as the suspected concussive event. Lastly, the diagnosis of a concussion was made by the on-site healthcare professional using their own clinical decision-making which improves the external validity of our study. The healthcare professionals participating in the ACHIVES Project also completed annual training on concussion assessment using the Child SCAT5 and followed an established concussion management protocol which limited variability in their clinical evaluation.