Telephone Triage in Pediatric Head Injury: Follow-up Patterns and Subsequent Diagnosis of Concussion

Abstract

Head injuries in childhood can result in concussion. Families of a child with a head injury often seek medical advice through telephone triage call systems. It is important to understand if patients follow telephone triage recommendations and what proportion of triage calls result in subsequent concussion diagnosis. We used a one-year retrospective cohort of triage calls screened with the Barton Schmitt Pediatric Head Injury Telephone Triage Protocol. The objectives were to estimate the proportion who followed up with urgent recommendations to see a provider and determine prevalence of diagnoses of concussion. Out of 2,454 calls with recommendations to be seen urgently, the estimated proportion of being seen in the medical home network or an outside health care facility was 84.1%. Estimated overall diagnoses of concussion among those who were seen was 39.5%. These data can be used to improve patient education and follow-up, as well as the utility of the telephone triage system.

Keywords

concussion head injury telephone triage system

Background & Significance

Head injuries in childhood can result in concussion. Each year, nearly 1.9 million children in the US experience a concussion (Bryan et al., 2016), which can affect cognition, concentration, processing speed, and oculomotor function (Sroufe et al., 2010; Thiagarajan et al., 2011; Thornhill et al., 2000; Vernau et al., 2015). In light of the prevalence of concussion in children and the potential negative sequalae, families of a child who has sustained a head injury often seek medical advice. One means by which families can access medical care is by calling their health care provider, which may be routed to a telephone triage call system affiliated with their health care provider. Thus, head injuries are a chief complaint for telephone triage call systems (Belman et al., 2005). Timely recognition of a concussion can influence appropriate clinical management, and it is important to understand if families follow up with recommendations made through calls to telephone triage systems (Arbogast et al., 2013; Grady, et al., 2012).

Telephone triage systems staffed by nurses that use standardized algorithms have been shown to be safe (Huibers et al., 2011; Kempe et al., 2001) and decrease costs associated with non-urgent use of the emergency department (Bogdan et al., 2004; Bunik et al., 2007; Fishe et al., 2016). Telephone triage systems are important in providing efficient clinical care for pediatric patients, yet their impact may be diminished if recommendations are not followed by families. In cases of head injury, pediatric patients may receive protocol recommendations to be seen urgently (e.g., call emergency medical services, visit an emergency department, or visit a health care provider within 24 hr) due to the risk for more serious injuries that require intervention. Evaluation during this acute phase, up to 3-days post-injury, is also important for the identification of complications (Kirkwood et al., 2008; Master et al., 2018).

An investigation of patterns of follow-up with urgent recommendations related to head injury provides information on how to optimize clinical practices and patient education related to telephone triage systems. Several studies have examined compliance with telephone triage recommendations, though not specifically addressing pediatric head injury or concussion. In a systematic review examining patient populations of all ages and no specific chief complaint, Blank and colleagues (2012) found great variation in patient/family compliance with telephone triage follow-up recommendations, ranging from 56% to 98% in their systematic review. Specific to the pediatric population, Crane and Benjamin (2000) found that 93.5% of their sample of pediatric patients in a community clinic complied with pediatric resident recommendations to be seen at an emergency department and 73.2% complied with the recommendation to make an appointment with their provider for the next day. Kempe and colleagues (2001) found in a pediatric multi-site study that compliance with the call center disposition recommendation was 83.3% for urgent referral and 41.0% for next day referral. In their meta-analysis of a pediatric population, Purc-Stephenson and Thrasher (2012) in their meta-analyses reported that families were more likely to comply with emergency department versus office visit recommendations (OR: 4.86 (95% CI: 3.04, 7.75, p < .001).

However, no studies have specifically looked at follow-up with telephone triage recommendations for urgent medical evaluation for head injury and concussion in the pediatric population. Since concussion occurs at a substantial rate among children and can lead to functional impairments, it is important to examine patient and family follow-up with these telephone triage recommendations. This study used a 1-year retrospective cohort of pediatric telephone triage calls from a pediatric health system that were screened with the Barton Schmitt Pediatric Head Injury Telephone Triage Protocol. The analysis focused on the sample that was recommended to seek care urgently (e.g., call emergency medical services, visit an emergency department, visit a health care provider within 24 hr) given the importance of timely concussion diagnosis after a head injury. The objectives were to describe patient and family follow-up patterns with telephone triage recommendations for urgent provider follow-up and to determine, among those who sought care, the prevalence of diagnoses of concussion.

Methods

In this retrospective descriptive study, we queried the electronic medical record for primary care telephone triage system calls from the Children’s Hospital of Philadelphia, a large integrated pediatric health healthcare network with a unified electronic health record (EHR) system. The Children’s Hospital of Philadelphia network includes a free-standing hospital, specialty care clinics, urgent care clinics and primary care practices with approximately 1.4 million outpatient visits and nearly 30,000 hospital admissions each year. Calls to primary care practices in this health system are staffed and triaged by registered nurses. This telephone triage system serves as an important point of access for those patients for whom Children’s Hospital of Philadelphia is their medical home. We searched the EHR for calls that used the Barton Schmitt Pediatric Head Injury Telephone Triage Protocol template from July 1, 2014 to June 30, 2015 and identified 6,004; we selected the most urgent recommendation when there was more than one. The Barton Schmitt Pediatric Head Injury Telephone Triage Protocol template contains pediatric-oriented decision-support tools that health care providers can use to guide the caller to the most appropriate medical care for their child (Schmitt, 2018). We excluded instances in which a patient made more than one call within 30 days, including on the same day, as those may indicate escalating or resolving symptoms (n = 688). Among those triage calls excluded, there was a median of 1 day between calls. We further restricted the calls for all patients to the first call in the time period (n = 5,106). We limited our population to triage calls for patients who were 17 years or younger at the time of the triage call (n = 5,045).

Two different work flows existed for this triage protocol, one for calls received during “Office Hours” (OH) (n = 3,096) and another for calls received “After Hours” (AH) (n = 1949). We also created two groups of urgent recommendations based on the Barton-Schmitt template. The recommendations to call 911, go to the emergency department, or go to an urgent care clinic were grouped as “Emergent.” The recommendations to be seen the same day or ≤ 24 hr in the provider’s office were grouped as “See ≤ 24 hours.” Of note, “see same day” was almost exclusively used for the OH protocol and “see ≤ 24 hours” was generally used for AH, reflecting a similar urgency for these recommendations for incoming calls at different times of day.

Since the proportion that follows up with recommendations might differ depending on the timing of the call, we created four categories based on a combination of protocol and type of urgent recommendation: (1) OH–Emergent (n = 305), (2) OH–See ≤ 24 hours (n = 1,335), (3) AH–Emergent (n = 540), and AH–See ≤ 24 hours (n = 274). The remainder of calls received for OH and AH were given recommendations for home care, see beyond 24 hr/same day, or speak with a provider and therefore were not included in this analysis (n = 2,590).

To evaluate patient and family follow-up with urgent triage recommendations, we first searched the EHR for the Children’s Hospital of Philadelphia network visits that followed each of the calls, accounting for both day and time of the calls. For the main variable of interest of first visit after the call, we 1) calculated the number of days between the call and the subsequent visit in the medical home network, 2) categorized whether it was within 7 days of the call, and 3) identified a diagnosis of concussion made at the visit. We refer to these visits as follow-up in the medical home network. The selection of 7-days was chosen to provide a window of opportunity for the patient and family to seek care, recognizing that concussion symptoms may increase after the initial injury (Master et al., 2018) and being seen within 24 hr may not be feasible in all instances. Prevalence of the diagnosis of concussion was identified through the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis code indicative of concussion (Arbogast et al., 2016). To rule out the concern that we might be missing more severe traumatic brain injury, we examined ICD-9-CM codes in those seen in the medical home, and found that only two cases had a more serious traumatic brain injury diagnosis (<0.10%) indicating that we were not greatly underestimating more serious head injury in the overall sample.

We also estimated the percentage of those not seen in the medical home network who were seen at an outside health care facility. We randomly sampled approximately 25% of the patients who did not have a visit to the medical home network within the 7-day window of their urgent recommendation for each of the four protocol/recommendation groups to identify if they were seen at an outside health care facility in that time period. Hand-review abstractions of the EHR were conducted for these groups. In the hand-review abstraction, we recorded data on whether the patient was seen at an outside health care facility in the 7-days post triage call and, for those who were seen, whether a diagnosis of concussion was made at the visit. During abstraction, we discovered that one person did not have a head injury; that person (in the “OH-Emergent” group) was removed from our overall population and the analysis of abstracted records.

To estimate overall follow-up with the urgent triage recommendations, that is, being seen within 7 days of the call at either the medical home network or an outside health care facility, we first extrapolated the findings for the proportions seen at an outside provider from the sampled populations to all such patients in the protocol/recommendation group. We then combined those estimates of the patients not seen at the medical home but seen elsewhere with the number seen at the medical home for each protocol/recommendation group to derive the overall numbers and proportions of patients seen anywhere. We applied a similar methodology to estimate the number and proportions of patients seen either at the medical home or elsewhere who were given a diagnosis of concussion. Analyses were conducted using SAS 9.4. This study was approved by the Institutional Review Board at the Children’s Hospital of Philadelphia.

Results

Table 1 outlines the demographic characteristics of the patients stratified by the four groups. Table 2 describes the proportion of patients who followed up in the medical home network within 7 days of the call, which ranged from 54.1% to 90.3% across the four groups. Among patients in the group OH- See ≤ 24 hr, 90.3% were seen at the medical home network within 7 days. In contrast, the proportion seen in the medical home network within 7 days was much less (approximately half to two-thirds) for the other groups (OH-Emergent: 54.1%; AH-Emergent: 60.7%, AH-See ≤24 hr: 65.3%). The days (median; Interquartile range (IQR)) from triage call to their visit among those seen in the medical home are reported in Table 2.

Table 1.

Demographics by Recommendation Group.

		OH-Emergent		OH-See≤24 hr		AH-Emergent		AH-See≤24 hr
Variable		N	%	N	%	N	%	N	%
All		305	12.4	1335	54.4	540	22.0	274	11.2
Age at nurse triage call	0–4	128	42.0	330	24.7	344	63.7	84	30.7
	5–11	106	34.8	463	34.7	120	22.2	106	38.7
	12–14	46	15.1	307	23.0	44	8.1	52	19.0
	15–17	25	8.2	235	17.6	32	5.9	32	11.7
Sex	Female	131	43.0	637	47.7	253	46.9	133	48.5
Sex	Male	174	57.0	698	52.3	287	53.1	141	51.5
Race/Ethnicity	Hispanic	34	11.1	68	5.1	25	4.6	10	3.6
	Non-Hispanic white	166	54.4	827	61.9	270	50.0	158	57.7
	Non-Hispanic black	60	19.7	284	21.3	169	31.3	65	23.7
	Non-Hispanic Asian/AI/Other/Multiple race	12	3.9	52	3.9	28	5.2	12	4.4
	Unknown	33	10.8	104	7.8	48	8.9	29	10.6

Table 2.

Follow-up Pattern by Recommendation Group.

	OH-Emergent (n = 305)		OH-See ≤24 hr (n = 1335)		AH-Emergent (n = 540)		AH-See ≤24 hr (n = 274)
	N or median	% or IQR	N or median	% or IQR	N or median	% or IQR	N or median	% or IQR
Seen at medical home network ≤7 days	165	54.1	1206	90.3	328	60.7	179	65.3
Days from triage call to next visit (median, IQR)	1	0, 3	0	0, 0	0	0, 2	1	0, 1
Seen by an outside provider ≤ 7 days*	18	48.6	5	16.1	25	45.5	0	0
Days from triage call to next visit (median, IQR)	0	0, 0	0	0, 0	0	0, 0	-	-
Estimated overall population	233	76.4	1227	91.9	424	78.5	179	65.3

25% abstracted group.

Abstraction of the ~25% in each of the four groups who did not have a visit to the medical home network within 7 days (n = 146) showed wide variation in whether there was documentation that the patient was seen at an outside health care facility within 7 days (Table 2). None of the AH-See ≤ 24 hr were found to have been seen at an outside health care facility; 16.1% of the group OH-See ≤ 24 hr were seen at a provider at an outside health care facility within 7 days; and 48.6% and 45.5%, respectively, of the OH-Emergent and AH-Emergent were seen at a provider at an outside health care facility within 7 days. The days (median; IQR) from triage call to next visit among those seen in an outside medical facility are reported in Table 2. The estimated proportion of being seen by any provider (medical home network or outside health care facility) was 84.1%, ranging from 65.3% to 91.9% in the four groups.

Table 3 outlines the diagnoses of concussion in the population. For those seen in the medical home network, 41.4% received a diagnosis of concussion. For those who were seen by a provider at an outside health care facility, 18.8% had a diagnosis of concussion by that outside provider. Estimated overall diagnoses of concussion among those who were seen by any provider (medical home network or outside) was 39.5%.

Table 3.

Number and Percent Given a Concussion Diagnosis by Recommendation Group and Follow-up Pattern.

	OH-Emergent		OH-See ≤24 hr		AH-Emergent		AH-See ≤24 hr
	N diagnosed/ N Seen	%	N diagnosed/ N Seen	%	N diagnosed/ N Seen	%	N diagnosed/ N Seen	%
Seen at medical home network ≤ 7 days	52/165	31.5	572/1206	47.4	79/328	24.1	75/179	41.9
Seen by an outside provider ≤ 7 days*	3/18	16.7	3/5	60.0	3/25	12.0	-	-
Estimated overall population	63/233	27.0	585/1227	47.7	91/424	21.5	75/179	41.9

25% abstracted group.

Discussion

In this analysis of one-year of triage call data, for the 5,045 calls that utilized the Barton Schmitt Pediatric Head Injury Telephone Triage Protocol for patients ages 0 to 17 years, 2,454 initial calls had recommendations to follow-up with a provider with emergency or urgent care, or within 24 hr/same day. We found varying follow-up with these urgent triage recommendations among patients calling during OH and AH and by recommendation disposition. These results add new information on triage patterns for pediatric patients with head injury and their subsequent steps in seeking care.

The highest proportion to follow up in our sample was among those calling during OH with the recommendation See ≤ 24 hr (estimated 91.9%). This may be related to the feasibility of calling during office hours and the family having the ability to schedule the visit immediately and take the child to the provider that same day or the next day. For those who are recommended to go to the ED or urgent care, proximity in location may prohibit being seen in the medical home network if they are going to the nearest facility. Even though we abstracted records seeking documentation of being seen elsewhere, it is possible a child was seen and that point of care was not recorded in the medical home network EHR.

The relatively lowest proportion for follow-up was in the AH-See ≤ 24 hr (estimated 65.3%). In their meta-analyses, Huibers and colleagues (2011) noted that symptom change was the second most common category for non-compliance (across patient populations). Though we did not evaluate the reasons or circumstances for not seeking care, it is possible that families may have made the decision not to seek care in the office the next day if symptoms improved overnight, without having made a second call to the triage call system.

The rate of concussion reported in this sample who sought care was estimated to be approximately 40%. Although there was a range in the proportion of concussion diagnoses between those made in the medical home network (41.1%) and those made by outside health care providers (18.8%), examining extensive contributing factors to these differences in concussion diagnoses was beyond the scope of this analysis. In the Children’s Hospital of Philadelphia health care network in 2012, there was an effort to increase provider awareness and education on concussion including introduction of an electronic clinical decision support tool (Arbogast et al., 2017; Fishe et al., 2016), which might account for the relatively higher rate of diagnosis of concussion in the patients seen in the medical home network. Though records were abstracted to identify visits to outside medical providers, it is possible a child was seen, and the documentation or communication of that information were not transferred to the medical home. Nonetheless, the estimated 40% rate among those seen highlights the prevalence of concussion diagnoses for pediatric patients who contact the telephone triage call system with concern for head injury. Future studies should explore the characteristics of those referred for urgent follow-up who ultimately did not receive a concussion diagnosis in order to further develop the triage algorithms and understand parental head injury concerns.

Patient education in the management of calls to triage systems is an important factor in helping parents follow-up on care recommendations. In their meta-analysis across studies with patients of various ages, Purc-Stephenson and Thrasher (2012) noted that non-compliance with triage recommendations was associated with recall problems of not hearing the same triage disposition as what was recorded, changes in symptoms (better or worse), need for a second opinion from another health care practitioner, or appointment availability. Head injuries and potential concussion can be a source of stress and fear for parents who often do not know how to gauge the seriousness of presenting symptoms, or the provider-recommended timing to seek care. Nurses taking the calls in the telephone triage system are specially trained to listen to parental concerns, follow the pertinent Barton-Schmitt pathway, and guide the parent on the appropriate disposition. The telephone triage system is a point of care where parents can receive one-on-one telephonic education and anticipatory guidance, which can be influential in how parents follow instructions given to them. Though the proportion being seen in the medical network home or by an outside health care provider was high in our sample (estimated 84.1%), attention to the communication of triage disposition remains key in the patient (or parent)-provider interaction.

We examined only 1 year of triage calls from one pediatric health network for this analysis. We did not evaluate factors that led to lack of follow-up with urgent triage recommendations. This is an important aspect of any future study in order to help improve how parents follow up for their child. It is possible that their child’s symptoms improved between the time they received instructions to follow up urgently and when they could arrange for a follow-up appointment. In addition, further examination of characteristics of patients who may or may not seek provider care when given the recommendation of home care would also be useful in how health care networks provide further education to the nurses triaging these calls. If nurses can understand the factors that often lead to either lack of follow-up or over-utilization of health care resources, they can be addressed in the sentinel call in hopes of maximizing optimal disposition for these patients.

Conclusion

From 1 year of triage calls that used the Barton Schmitt Pediatric Head Injury Telephone Triage Protocol within a large pediatric healthcare network, almost half were referred to seek follow-up care urgently. Of those, the majority (84%) followed up by being seen in the medical home network or an outside care provider. Approximately 40% of those seen received a diagnosis of concussion. With standardized recommendations and triage decision algorithms from nurse protocols, health care networks that have an integrated primary care system and emergency department with a connected EHR system can track patient adherence to recommendations to seek further clinical care. These data can be used to determine ways to improve parental education and compliance with follow-up recommendations, as well as improve the utility of the telephone triage system.

Footnotes

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Catherine C. McDonald

Author Biographies

Catherine C. McDonald, PhD, RN, FAAN is an assistant professor of Nursing at the University of Pennsylvania with a secondary appointment as an Assistant Professor of Pediatric Nursing at the Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania and the Center for Injury Research and Prevention at The Children’s Hospital of Philadelphia.

Melissa R. Pfeiffer, MPH is a senior biostatistician at the Center for Injury Research and Prevention at Children’s Hospital of Philadelphia.

Roni L. Robinson, RN, MSN, CRNP is a Pediatric Nurse Practitioner at Children’s Hospital of Philadelphia in the Departments of Orthopedics and Trauma Program.

Kristy B. Arbogast, PhD is the Co-Scientific Director of the Center for Injury Research and Prevention at Children’s Hospital of Philadelphia and the R. Anderson Pew Endowed Chair and Professor of Pediatrics at the University of Pennsylvania Perelman School of Medicine.

Christina L. Master, MD, FAAP, CAQSM is a Professor of Clinical Pediatrics at the University of Pennsylvania Perelman School of Medicine, a sports medicine physician, scholar at the Center for Injury Research and Prevention and Co-Director of the Minds Matter Concussion Program at Children’s Hospital of Philadelphia.

References

Arbogast

K. B.

Curry

A. E.

Metzger

K. B.

Kessler

R. S.

Bell

J. M.

Haarbauer-Krupa

Zonfrillo

M. R.

Breiding

M. J.

Master

C. L.

(2017). Improving primary care provider practices in youth concussion management. Clinical Pediatrics, 56(9), 854–865. https://doi.org/10.1177/0009922817709555

Arbogast

K. B.

Curry

A. E.

Pfeiffer

M. R.

Zonfrillo

M. R.

Haarbauer-Krupa

Breiding

M. J.

Coronado

V. G.

Master

C. L.

(2016). Point of health care entry for youth with concussion within a large pediatric care network. JAMA Pediatrics, 170(7), e160294. https://doi.org/10.1001/jamapediatrics.2016.0294

Arbogast

K. B.

McGinley

A. D.

Master

C. L.

Grady

M. F.

Robinson

R. L.

Zonfrillo

M. R.

(2013). Cognitive rest and school-based recommendations following pediatric concussion. Clinical Pediatrics, 52(5), 397–402. https://doi.org/10.1177/0009922813478160

Belman

Chandramouli

Schmitt

B. D.

Poole

S. R.

Hegarty

Kempe

(2005). An assessment of pediatric after-hours telephone care. Archives of Pediatrics & Adolescent Medicine, 159(2), 145–149. https://doi.org/10.1001/archpedi.159.2.145

Blank

Coster

O’Cathain

Knowles

Tosh

Turner

Nicholl

(2012). The appropriateness of, and compliance with, telephone triage decisions: A systematic review and narrative synthesis. Journal of Advanced Nursing, 68(12), 2610–2621. https://doi.org/10.1111/j.1365-2648.2012.06052.x

Bogdan

G. M.

Green

J. L.

Swanson

Gabow

Dart

R. C.

(2004). Evaluating patient compliance with nurse advice line recommendations and the impact on healthcare costs. The American Journal of Managed Care, 10(8), 534–542. http://www.ajmc.com/journals/issue/2004/2004-08-vol10-n8/aug04-1843p534-542

Bryan

M. A.

Rowhani-Rahbar

Comstock

R. D.

Rivara

, & On behalf of the Seattle Sports Concussion Research Collaborative. (2016). Sports- and recreation-related concussions in US youth. Pediatrics, 138(1), 1–8.

Bunik

Glazner

J. E.

Chandramouli

Emsermann

C. B.

Hegarty

Kempe

(2007). Pediatric telephone call centers: How do they affect health care use and costs? Pediatrics, 119(2), e305–e313. https://doi.org/10.1542/peds.2006-1511

Crane

J. D.

Benjamin

J. T.

(2000). Pediatric residents’ telephone triage experience do parents really follow telephone advice? Archives of Pediatrics & Adolescent Medicine, 154(1), 71–74.

10.

Fishe

J. N.

Luberti

A. A.

Master

C. L.

Robinson

R. L.

Grady

M. F.

Arbogast

K. B.

Zonfrillo

M. R.

(2016). After-hours call center triage of pediatric head injury: Outcomes after a concussion initiative. Pediatric Emergency Care, 32(3), 149–153. https://doi.org/10.1097/pec.0000000000000724

11.

Grady

M. F.

Master

C. L.

Gioia

G. A.

(2012). Concussion pathophysiology: Rationale for physical and cognitive rest. Pediatric Annals, 41(9), 377–382. https://doi.org/10.3928/00904481-20120827-12

12.

Huibers

Smits

Renaud

Giesen

Wensing

(2011). Safety of telephone triage in out-of-hours care: A systematic review. Scandinavian Journal of Primary Health Care, 29(4), 198–209. https://doi.org/10.3109/02813432.2011.629150

13.

Kempe

Luberti

A. A.

Hertz

A. R.

Sherman

H. B.

Amin

Dempsey

Chandramouli

MacKenzie

Hegarty

T. W.

(2001). Delivery of pediatric after-hours care by call centers: A multicenter study of parental perceptions and compliance. Pediatrics, 108(6), e111 LP–e111. http://pediatrics.aappublications.org/content/108/6/e111.abstract

14.

Kirkwood

M. W.

Yeates

K. O.

Taylor

H. G.

Randolph

McCrea

Anderson

V. A.

(2008). Management of pediatric mild traumatic brain injury: A neuropsychological review from injury through recovery. The Clinical Neuropsychologist, 22(5), 769–800. https://doi.org/10.1080/13854040701543700

15.

Master

C. L.

Mayer

A. R.

Quinn

Grady

M. F.

(2018). Concussion. Annals of Internal Medicine, 169(1), ITC1–ITC16. https://doi.org/10.7326/AITC201807030

16.

Purc-Stephenson

R. J.

Thrasher

(2012). Patient compliance with telephone triage recommendations: A meta-analytic review. Patient Education and Counseling, 87(2), 135–142. https://doi.org/10.1016/J.PEC.2011.08.019

17.

Schmitt

B. D.

(2018). Pediatric telephone protocols (16th ed.). American Academy of Pediatrics.

18.

Sroufe

N. S.

Fuller

D. S.

West

B. T.

Singal

B. M.

Warschausky

S. A.

Maio

R. F.

(2010). Postconcussive symptoms and neurocognitive function after mild traumatic brain injury in children. Pediatrics, 125(6), e1331–e1339.

19.

Thiagarajan

Ciuffreda

K. J.

Ludlam

D. P.

(2011). Vergence dysfunction in mild traumatic brain injury (mTBI): A review. Ophthalmic and Physiological Optics, 31(5), 456–468.

20.

Thornhill

Teasdale

G. M.

Murray

G. D.

McEwen

Roy

C. W.

Penny

K. I.

(2000). Disability in young people and adults one year after head injury: Prospective cohort study. BMJ, 320(7250), 1631–1635.

21.

Vernau

B. T.

Grady

M. F.

Goodman

Wiebe

D. J.

Basta

Park

Arbogast

K. B.

Master

C. L.

(2015). Oculomotor and neurocognitive assessment of youth ice hockey players: Baseline associations and observations after concussion. Developmental Neuropsychology, 40(1), 7–11.