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BACKGROUND:

Headache is a common complaint among children presenting to the emergency department (ED) and can be due to serious neurologic and nonneurologic diagnoses (SNNDs). We sought to characterize the children discharged from the ED with headache found to have SNNDs at revisits.

METHODS:

We performed a multicenter retrospective cohort study using data from 45 pediatric hospitals from October 1, 2015, to March 31, 2019. We included pediatric patients (≤18 years) discharged from the ED with a principal diagnosis of headache, excluding patients with concurrent or previous SNNDs or neurosurgeries. We identified rates and types of SNNDs diagnosed within 30 days of initial visit and compared these rates with those of control groups defined as patients with discharge diagnoses of cough, chest pain, abdominal pain, and soft tissue complaints.

RESULTS:

Of 121 621 included patients (57% female, median age 12.4 years, interquartile range: 8.8–15.4), 608 (0.5%, 95% confidence interval: 0.5%–0.5%) were diagnosed with SNNDs within 30 days. Most were diagnosed at the first revisit (80.8%); 37.5% were diagnosed within 7 days. The most common SNNDs were benign intracranial hypertension, cerebral edema and compression, and seizures. A greater proportion of patients with SNNDs underwent neuroimaging, blood, and cerebrospinal fluid testing compared with those without SNNDs (P < .001 for each). The proportion of SNNDs among patients diagnosed with headache (0.5%) was higher than for control cohorts (0.0%–0.1%) (P < .001 for each).

CONCLUSIONS:

A total 0.5% of pediatric patients discharged from the ED with headache were diagnosed with an SNND within 30 days. Further efforts to identify at-risk patients remain a challenge.

What’s Known on This Subject:

Headache is a common complaint in pediatric emergency departments (EDs) and is usually due to benign etiologies. However, some are due to serious diagnoses. We have limited understanding of children discharged with headache and later found to have serious disease.

What This Study Adds:

We identified children discharged from pediatric EDs with headache and later found to have serious diagnoses. The rate of serious diagnoses is low (0.5%); these patients underwent more testing at the index ED visit than patients without serious diagnoses.

Headache is prevalent in the pediatric population, with up to 80% of children diagnosed with headache in one year1,2  and up to 40% experiencing headache in one week.3  Although there are outpatient resources for headache management,4  it is one of the most common neurologic reasons for admissions.57  Similarly, headache is a common chief complaint in pediatric emergency departments (EDs).8,9  Although the majority of headaches are benign, researchers in single-center prospective10  and retrospective9,1115  studies estimate that 1% to 15% of patients with headache evaluated in the ED have serious etiologies, including vascular malformations, neoplasms, and bacterial meningitis. The identification of such cases in the ED requires careful evaluation, often aided by diagnostic testing. Neuroimaging, including computed tomography (CT) and MRI, is an important diagnostic tool to evaluate many serious neurologic conditions. However, such testing is not always indicated. Current guidelines from the American Academy of Neurology recommend neuroimaging in children with headache only if they have an abnormal neurologic examination or symptoms to suggest neurologic dysfunction.16  Although over-testing exposes children to the risks of radiation, sedation, incidental findings, and increased cost and length of stay,1719  under-testing can lead to missed serious neurologic and nonneurologic diagnoses (SNNDs).2022 

To date, there has been limited investigation into the frequency of missed SNNDs among children discharged from the ED. Previous studies in children have been limited to single centers and small cohorts of a few hundred patients.915,23  Therefore, our objective was to evaluate the rates of SNNDs among pediatric patients discharged from the ED with a diagnosis of headache by using a large, multicenter cohort.

We performed a multicenter, retrospective cohort study using administrative data provided by the Pediatric Health Information System (PHIS), a database that contains billing data from ED, inpatient, ambulatory surgery, and observation units from geographically diverse children’s hospitals in the United States affiliated with the Children’s Hospital Association (Overland Park, KS). Contributing hospitals are located in 26 states and the District of Columbia. Encounters are deidentified but assigned unique patient identifiers to allow for tracking across multiple encounters. The Children’s Hospital Association and participating hospitals jointly ensure the data quality and integrity. We included data from 45 hospitals in PHIS for this study. The Ann and Robert H. Lurie Children’s Hospital Institutional Review Board deemed this study exempt from the requirement for informed consent.

We included patients ≤18 years of age with an International Classification of Diseases,10th Revision, Clinical Modification (ICD-10-CM), principal diagnosis code of headache (R51.X [headache], G43.X [migraine], and G44.X [other headache syndromes]) who were billed for ED encounters and discharged between October 1, 2015, and March 31, 2019.

For patients with multiple ED encounters within the assessed time frame, we considered the first encounter as the index visit and subsequent encounters as revisits. We excluded ED encounters that were transfers from another hospital or resulted in admissions. As in previous studies,15,23,24  we excluded encounters associated with trauma or poisoning (any associated ICD-10-CM diagnosis code of S00-T88). We excluded patients who had an SNND made during or previous to the index visit. We also excluded those with previous history of neurosurgeries, defined as the presence of any previously billed procedure performed by a physician with a specialty of neurologic surgery. We applied these exclusions by considering all encounters available in PHIS for each patient, including inpatient and ambulatory surgery encounters. To determine which patients met the exclusion criteria of a previously diagnosed SNND before October 2015, when ICD-10-CM was universally implemented, we used generalized equivalence mapping, a resource provided by the Centers for Medicare and Medicaid services,25  to perform backward mapping of the ICD-10-CM codes to International Classification of Diseases, Ninth Revision codes.

To evaluate if our outcomes were confounded by a baseline incidence of SNNDs, we performed analyses of SNND rates for four other index visit diagnoses: cough (R05), chest pain (R07), abdominal pain (R10), and soft tissue complaints (M79), consistent with previous methods.24  We applied the same exclusions for these cohorts as for the primary cohort.

We evaluated the following: demographics (age, sex, race, ethnicity, primary payer, and geographic region), chronic conditions, and diagnostic testing. We categorized age into subgroups of infants and toddlers (0–2 years), young children (3–5 years), older children (6–12 years), and adolescents (13–18 years). We defined chronic conditions using the complex chronic conditions (CCCs) flag in PHIS, which is based on encounter-level diagnosis codes.26  Diagnostic tests at the index visit were defined as neuroimaging (ie, head CT or brain MRI), EEG, blood, and cerebrospinal fluid (CSF) testing.

Because secondary headaches of significant etiology can be of neurologic or nonneurologic origin, our outcomes of interest were patients with SNNDs, billed as either a primary or associated diagnosis on revisits within 30 days of the index visit. A priori, we determined 30 days as the follow-up period for diagnosis on the basis of a similar previous study in the adult ED population.17  Furthermore, 30 days is a time frame during which many acute etiologies can re-present.14,27,28  If a patient was diagnosed with multiple SNNDs during the 30-day period, the first revisit where one or more SNNDs were diagnosed was considered the revisit by which time to diagnosis was calculated.

Two investigators (A.Z.Z. and J.R.M.) developed the list of SNNDs on the basis of previous literature defining serious causes of secondary headache.14,15,24,29,30  The list consists of >100 diagnoses, each representing a distinct ICD-10-CM billable code. These were consolidated into 22 mutually exclusive categories based on the diagnoses (Table 1). For example, malignant neoplasm of the pituitary gland (C75.1) was combined with malignant neoplasm of cerebral meninges (C70.0, C70.9) and other diagnoses of central nervous system malignancies to make the category of malignant neoplasms.

TABLE 1

SNNDs

DiagnosisICD-10-CM Diagnosis Code(s)
Malignant neoplasms C70.0, C70.9, C71, C71.x, C72.2x, C72.3x, C72.4x, C72.50, C72.59, C72.9, C75.1, C75.2, C75.3, C69, C69.x, C69.xx 
Bacterial meningitis G00, G00.x, G04.2 
Encephalitis, myelitis and encephalomyelitis G04.8, G04.90, G04.91, G05.3, G05.4, G37.4 
Intracranial and intraspinal abscess G06.0, G06.1, G06.2, G09 
Phlebitis and thrombophlebitis of intracranial venous sinuses G08, I67.6, O87.3, O22.5x 
Benign intracranial hypertension G93.2 
Cerebral edema and compression G93.5, G93.6 
Acute angle-closure glaucoma H40.2x 
Hypertension I10, I67.4 
Intracranial hemorrhage I60.x, I61.x, I62.x 
Cerebral artery occlusion, ischemia, and stroke I63.x, I65.x, I66.x, 167.2, I67.9, I68.0, I68.8, G45.0, G45.8, G45.9, G46.x 
Cerebral artery dissection and aneurysms I67.1, I72.0, I72.5, I72.6, I77.71, I77.74 
Cerebral arteritis M31.5, M31.6, I67.7, I68.2 
Preeclampsia O14.x 
Cerebral vascular malformations I67.5, Q28.2, Q28.3 
Ventricular shunt malfunction T85.0x, T85.730x 
Hydrocephalus G91.x, Q03.x, Q05.x, Q07.02 
Seizures G40.x 
Mitochondrial encephalopathy, lactic acidosis and stroke-like episodes E88.41 
Optic neuritis H46, H46.x 
Multiple sclerosis G35 
Acute disseminated encephalomyelitis G04.0, G04.01 
DiagnosisICD-10-CM Diagnosis Code(s)
Malignant neoplasms C70.0, C70.9, C71, C71.x, C72.2x, C72.3x, C72.4x, C72.50, C72.59, C72.9, C75.1, C75.2, C75.3, C69, C69.x, C69.xx 
Bacterial meningitis G00, G00.x, G04.2 
Encephalitis, myelitis and encephalomyelitis G04.8, G04.90, G04.91, G05.3, G05.4, G37.4 
Intracranial and intraspinal abscess G06.0, G06.1, G06.2, G09 
Phlebitis and thrombophlebitis of intracranial venous sinuses G08, I67.6, O87.3, O22.5x 
Benign intracranial hypertension G93.2 
Cerebral edema and compression G93.5, G93.6 
Acute angle-closure glaucoma H40.2x 
Hypertension I10, I67.4 
Intracranial hemorrhage I60.x, I61.x, I62.x 
Cerebral artery occlusion, ischemia, and stroke I63.x, I65.x, I66.x, 167.2, I67.9, I68.0, I68.8, G45.0, G45.8, G45.9, G46.x 
Cerebral artery dissection and aneurysms I67.1, I72.0, I72.5, I72.6, I77.71, I77.74 
Cerebral arteritis M31.5, M31.6, I67.7, I68.2 
Preeclampsia O14.x 
Cerebral vascular malformations I67.5, Q28.2, Q28.3 
Ventricular shunt malfunction T85.0x, T85.730x 
Hydrocephalus G91.x, Q03.x, Q05.x, Q07.02 
Seizures G40.x 
Mitochondrial encephalopathy, lactic acidosis and stroke-like episodes E88.41 
Optic neuritis H46, H46.x 
Multiple sclerosis G35 
Acute disseminated encephalomyelitis G04.0, G04.01 

CM, Clinical Modification.

For all included hospitals, we examined the length of time available for previous assessments of SNNDs and neurosurgery using data provided by the Children’s Hospital Association. We assessed the rate of return visits to the ED over the 30-day period and the proportion of patients having the outcome of interest during this time. Because patients may have had >1 SNND identified during the 30-day period, we identified the time to the first SNND diagnosis with respect to the number of days (0–7 days and 8–30 days) and number of ED revisits until diagnosis (1, 2, 3, 4, and ≥5). We reported demographics, presence of complex conditions, and rates of diagnostic testing. For control cohorts, we identified rates of SNNDs within 30 days of their index visit and compared overall rates of SNNDs with the primary cohort. Analyses were conducted with R version 3.6.1 (R Foundation for Statistical Computing, Vienna, Austria; https://www.R-project.org/).

First, to assess the impact of only including those with a principal discharge diagnosis of headache, we performed a sensitivity analysis expanding the inclusion criteria to include patients discharged from the ED with headache coded in any of the discharge diagnosis positions. Second, to evaluate for differences in diagnostic testing at the index visit between patients diagnosed with SNND at the index visit versus those diagnosed at revisits, we performed a post hoc analysis. In this analysis, we expanded the inclusion criteria as follows: (1) to include patients with any diagnosis of headache as in the aforementioned sensitivity analysis and (2) to include patients who had an SNND diagnosed at their index visit, regardless of whether they were discharged or admitted. We compared the rates of diagnostic testing among patients who had an SNND diagnosed on their index visit with those with an SNND diagnosed within 30 days of the index visit using χ2 testing. The P values <.05 were considered statistically significant.

A total of 181 423 encounters were identified in the initial search query. After applying exclusions, 121 621 patients were retained in the study cohort (Fig 1). The median patient age was 12.4 years (interquartile range: 8.8–15.4 years), and 57.1% were female. The 45 included hospitals contributed data to PHIS for a median duration of 14.8 years (interquartile range: 7.6–15.8 years) by the end of the 30-day follow-up period on April 30, 2019.

FIGURE 1

Patient cohort.

A total of 608 patients (0.5%; 95% confidence interval: 0.5%–0.5%) had ≥1 SNND identified within 30 days of the index visit. Of these, 37.5% had their first SNND diagnosed within 7 days of the index visit (Fig 2), and 80.8% had their first SNND diagnosed at the first ED revisit (Fig 3). A total of 13 189 patients (10.8%) had ≥1 ED revisit within 30 days of their index visit. Of patients with revisits, 82.7% had 1, 13.6% had 2, 2.8% had 3, 0.7% had 4, and 0.3% had ≥5 revisits. Most diagnoses of headache occurred in children ≥3 years of age. There was little variation in the rate of SNNDs by sex, race, ethnicity, insurance type, and geographic region. Patients with CCCs were more likely to have an SNND diagnosed at ED revisits (1.5%) compared with those without CCCs (0.5%) (Supplemental Table 5).

FIGURE 2

Number of patients (left axis) and cumulative percent of patients (right axis) with SNNDs diagnosed over time.

FIGURE 2

Number of patients (left axis) and cumulative percent of patients (right axis) with SNNDs diagnosed over time.

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FIGURE 3

Number of patients with SNNDs diagnosed, by revisit number.

FIGURE 3

Number of patients with SNNDs diagnosed, by revisit number.

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Seven hundred ninety SNNDs were identified among 608 patients meeting criteria for the primary outcome (Table 2). The most common SNNDs were benign intracranial hypertension (24.1%), cerebral edema and compression (15.2%), and seizures (11.5%). Patients with SNNDs had higher rates of neuroimaging (MRI and CT), blood, and CSF studies compared with patients without SNNDs (P < .001 for each, Table 3). For example, 25.0% of patients with SNNDs had neuroimaging at the index visit, compared with 16.0% of patients without SNNDs.

TABLE 2

Serious Diagnoses Overall and Stratified by Follow-up Period

ICD-10-CM DiagnosesTotal No. Diagnoses, n (Column %)0–7 d, n (Row %)8–30 d, n (Row %)
All SNNDs, total 790 262 (33.2) 528 (66.8) 
Benign intracranial hypertension 190 (24.1) 80 (42.1) 110 (57.9) 
Cerebral edema and compression 120 (15.2) 37 (30.8) 83 (69.2) 
Seizures 91 (11.5) 36 (39.6) 55 (60.4) 
Hypertension 86 (10.9) 37 (43.0) 49 (57.0) 
Ventricular shunt malfunction 77 (9.7) 22 (28.6) 55 (71.4) 
Malignant neoplasms 41 (5.2) 8 (19.5) 33 (80.5) 
Encephalitis and myelitis 31 (3.9) 7 (22.6) 24 (77.4) 
Intracranial and intraspinal abscess 24 (3.0) 2 (8.3) 22 (91.7) 
Intracranial hemorrhage 24 (3.0) 11 (45.8) 13 (54.2) 
Phlebitis and thrombophlebitis of intracranial venous sinuses 21 (2.7) 2 (9.5) 19 (90.5) 
Cerebral artery occlusion, ischemia, stroke 19 (2.4) 1 (5.3) 18 (94.7) 
Optic neuritis 18 (2.3) 4 (22.2) 14 (77.8) 
Cerebral vascular malformations 14 (1.8) 7 (50.0) 7 (50.0) 
Bacterial meningitis 12 (1.5) 4 (33.3) 8 (66.7) 
ADEM 11 (1.4) 1 (9.1) 10 (90.9) 
Multiple sclerosis 6 (0.8) 3 (50.0) 3 (50.0) 
Cerebral artery dissection and aneurysms 4 (0.5) 0 (0.0) 4 (100.0) 
Cerebral arteritis 1 (0.1) 0 (0.0) 1 (100.0) 
Preeclampsia 0 (0.0) 0 (0.0) 0 (0.0) 
Hydrocephalus 0 (0.0) 0 (0.0) 0 (0.0) 
Acute angle-closure glaucoma 0 (0.0) 0 (0.0) 0 (0.0) 
MELAS 0 (0.0) 0 (0.0) 0 (0.0) 
ICD-10-CM DiagnosesTotal No. Diagnoses, n (Column %)0–7 d, n (Row %)8–30 d, n (Row %)
All SNNDs, total 790 262 (33.2) 528 (66.8) 
Benign intracranial hypertension 190 (24.1) 80 (42.1) 110 (57.9) 
Cerebral edema and compression 120 (15.2) 37 (30.8) 83 (69.2) 
Seizures 91 (11.5) 36 (39.6) 55 (60.4) 
Hypertension 86 (10.9) 37 (43.0) 49 (57.0) 
Ventricular shunt malfunction 77 (9.7) 22 (28.6) 55 (71.4) 
Malignant neoplasms 41 (5.2) 8 (19.5) 33 (80.5) 
Encephalitis and myelitis 31 (3.9) 7 (22.6) 24 (77.4) 
Intracranial and intraspinal abscess 24 (3.0) 2 (8.3) 22 (91.7) 
Intracranial hemorrhage 24 (3.0) 11 (45.8) 13 (54.2) 
Phlebitis and thrombophlebitis of intracranial venous sinuses 21 (2.7) 2 (9.5) 19 (90.5) 
Cerebral artery occlusion, ischemia, stroke 19 (2.4) 1 (5.3) 18 (94.7) 
Optic neuritis 18 (2.3) 4 (22.2) 14 (77.8) 
Cerebral vascular malformations 14 (1.8) 7 (50.0) 7 (50.0) 
Bacterial meningitis 12 (1.5) 4 (33.3) 8 (66.7) 
ADEM 11 (1.4) 1 (9.1) 10 (90.9) 
Multiple sclerosis 6 (0.8) 3 (50.0) 3 (50.0) 
Cerebral artery dissection and aneurysms 4 (0.5) 0 (0.0) 4 (100.0) 
Cerebral arteritis 1 (0.1) 0 (0.0) 1 (100.0) 
Preeclampsia 0 (0.0) 0 (0.0) 0 (0.0) 
Hydrocephalus 0 (0.0) 0 (0.0) 0 (0.0) 
Acute angle-closure glaucoma 0 (0.0) 0 (0.0) 0 (0.0) 
MELAS 0 (0.0) 0 (0.0) 0 (0.0) 

ADEM, Acute disseminated encephalomyelitis; MELAS, mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes.

TABLE 3

Number of Patients With Diagnostic Tests at Index Visit

Diagnostic RestNo SNND (Total n = 121 013), n (%)Has SNND (Total n = 608), n (%)P
Any neuroimaginga 19 344 (16.0) 152 (25.0) <.001 
 CT 15 678 (13.0) 117 (19.2) <.001 
 MRI 3898 (3.2) 37 (6.1) <.001 
Blood tests 22 862 (18.9) 205 (33.7) <.001 
CSF studies 696 (0.6) 17 (2.8) <.001 
EEG 80 (0.1) 0 (0.0) .53 
Diagnostic RestNo SNND (Total n = 121 013), n (%)Has SNND (Total n = 608), n (%)P
Any neuroimaginga 19 344 (16.0) 152 (25.0) <.001 
 CT 15 678 (13.0) 117 (19.2) <.001 
 MRI 3898 (3.2) 37 (6.1) <.001 
Blood tests 22 862 (18.9) 205 (33.7) <.001 
CSF studies 696 (0.6) 17 (2.8) <.001 
EEG 80 (0.1) 0 (0.0) .53 
a

Some patients underwent both CT and MRI.

We analyzed rates of SNND on revisits among four control cohorts with principal discharge diagnoses of cough, chest pain, abdominal pain, and soft tissue complaints. The incidence of SNND in control cohorts ranged from 0.0% to 0.1% (Table 4). These were significantly lower than the 0.5% incidence of SNNDs identified in the primary headache cohort (P < .001 for each control cohort comparison).

TABLE 4

Rates of Serious Diagnoses Identified Within 30 Days of the Index Visit in the Control Cohort

Principal Diagnosis (ICD-10-CM Code)nNo. Patients With SNNDs (%)P
Cough (R05.x) 118 516 53 (0.0) <.001 
Chest pain (R07.x) 82 743 81 (0.1) <.001 
Abdominal pain (R10.x) 272 915 228 (0.1) <.001 
Soft tissue complaints (M79.x) 58 976 64 (0.1) <.001 
Principal Diagnosis (ICD-10-CM Code)nNo. Patients With SNNDs (%)P
Cough (R05.x) 118 516 53 (0.0) <.001 
Chest pain (R07.x) 82 743 81 (0.1) <.001 
Abdominal pain (R10.x) 272 915 228 (0.1) <.001 
Soft tissue complaints (M79.x) 58 976 64 (0.1) <.001 

The P value was derived as a χ2 test of comparing each control group to the primary headache cohort.

To explore whether our primary outcome is similar for patients with any associated diagnosis of headache and not only a principal diagnosis of headache, we used an expanded inclusion criteria of patients with any (primary or associated) diagnosis of headache. A total of 205 927 patients were included (Supplemental Fig 4). The rate of SNND in this cohort was 0.4% (95% confidence interval: 0.4%–0.4%). The demographics, types of SNNDs, and extent of diagnostic testing were similar to the primary cohort (Supplemental Tables 6 and 7).

We performed an additional analysis to determine if patients diagnosed with SNNDs at revisits had different rates of testing at the index visit compared with patients diagnosed with SNNDs at the index visit (Supplemental Fig 5). Patients diagnosed at the index visit underwent significantly more neuroimaging, blood, CSF, and EEG studies than patients diagnosed at revisits (P < .001 for each, Supplemental Table 8).

In this multicenter study of pediatric patients discharged from the ED with headache, the rate of SNNDs diagnosed within 30 days was 0.5%. Although low, this figure was significantly higher than rates among control cohort patients with other diagnoses. Nearly 40% of patients with SNNDs were identified within a week of the index ED visit, and 80% of patients were identified at the first ED revisit. Patients diagnosed with an SNND at ED revisits had higher rates of diagnostic testing at index visits than those without SNNDs. Benign intracranial hypertension, cerebral edema and compression, and seizures were the most common SNNDs.

Our finding of an SNND rate of 0.5% among pediatric patients discharged from the ED with headache is lower than that found in other studies, which have reported rates between 1% and 15%. One single-center study reported SNNDs in 4% of the 526 patients discharged from the ED with headache.5  Another single-center study of 295 patients with headache found that 4% were subsequently diagnosed with SNNDs within 5 days of the index ED visit.14  There are several potential reasons for the differences in our rate. First, our larger sample may have resulted in regression toward the mean. Second, we excluded patients with previous neurosurgery and SNND and those with trauma and SNND at their index visit. The rate of serious disease is likely higher in these excluded patients. Third, we limited our outcome to ED revisits, which does not account for other visits and diagnoses in the outpatient setting.

Our SNND rate of 0.5% is similar to the findings in a recent study of adult patients in which researchers used similar inclusion criteria and a 30-day follow-up period.24  The most common SNNDs in that study were cerebral artery occlusion, subarachnoid hemorrhage, and transient cerebral ischemia. These etiologies, which carry high mortality or morbidity, constituted 40% of the total SNNDs in that study. In contrast, such etiologies represented a minority of pediatric patients in our study (<6%). The most common SNNDs identified in our study generally carried lower morbidity and mortality. An examination of the 86 diagnoses of hypertension (Table 2) revealed 3 patients with an ICD-10-CM diagnosis of hypertensive encephalopathy (diagnosis code I67.4). The other 83 patients were diagnosed with essential hypertension only (diagnosis code I10), which encompasses malignant, benign, and unspecified hypertension. Hypertension is typically diagnosed in the outpatient setting, unless the patient has hypertensive emergency or urgency or signs of end-organ damage.3133  Therefore, it is possible that some of the 83 patients did not meet criteria for the diagnosis but rather were erroneously labeled as hypertensive because of elevated blood pressures at the ED revisit. Therefore, the true rate of serious diagnoses is likely lower than 0.5%.

In our study, SNNDs requiring acute interventions, such as ventricular shunt malfunction and malignant neoplasms, occurred at low rates. Cerebral edema and compression was the second-most common SNND identified, representing 15.2% of all patients with SNNDs and <0.1% of the overall patient cohort discharged from the index ED visit with headache. On review of the 120 patients with this condition, 51 patients (43%) had ≥1 other SNNDs, including, most commonly, ventricular shunt malfunction (n = 21), malignant neoplasms (n = 13), and intracranial hemorrhage (n = 11). This suggests that many patients were diagnosed with cerebral edema and compression secondary to another SNND.

A larger proportion of patients diagnosed with SNNDs at revisits had diagnostic testing at index visits compared with those not diagnosed with SNNDs. These findings suggest that patients ultimately diagnosed with SNNDs were subject to a higher degree of scrutiny at their index visit. Therefore, additional efforts to identify SNNDs at the index visit would be limited. In such patients, timely diagnosis may be facilitated through close outpatient follow-up. For example, one center referred a subset of children for neurology clinic appointments within one week of their ED visit for headache, thereby offering a safety net for patients with signs and symptoms concerning for serious secondary etiologies.15  Another study revealed that children who established headache center follow-up after the index visit were less likely to revisit the ED with headache.14  Furthermore, some SNNDs, such as hypertension, require longitudinal follow-up to definitively establish the diagnosis.3133  Our results also highlight the need for additional research to identify which patients require neuroimaging at the index visits.16  Given the rarity of abnormal findings, a case-control strategy may best identify factors associated with pediatric SNNDs.

The findings from this study are subject to the limitations of a retrospective analysis using billing data, including errors with coding accuracy and data availability.34  Notably, the PHIS data set does not contain clinical data, including vital signs and neurologic examination findings. In addition, this study only included patients at specialty pediatric hospitals, which may limit generalizability because an estimated 85% of children in the United States seek care in general EDs.3537  Hospitals contributed data to PHIS over varying time periods, and it is possible some patients included in the cohort were not identified as having previous SNNDs or neurosurgeries. This misclassification would result in an overestimation of the SNND rate. A repeat analysis limited to 33 hospitals that contributed data for ≥5 years before the study inclusion period revealed a similar rate of SNNDs at 30-day follow-up (0.5%), suggesting that this was not a substantial limitation (results not shown). We did not have data from outpatient visits that may have occurred, because PHIS does not include these data. Similarly, we were unable to capture subsequent visits to a different ED than the index ED. However, previous studies have indicated that only a minority of revisits are to a different ED. Researchers in one study evaluated return visits among nearly 700 000 pediatric patients at 22 EDs and found that only 0.3% of patients had a revisit to a different ED within one year of the index visit.38  In another study of pediatric patients in general and pediatric EDs, 97.7% of patients were occasional ED users, of which only 7.7% visited ≥2 hospitals in a one-year period.39  Therefore, it is unlikely that a substantial number of SNNDs were missed because of revisits to a different ED.

Among patients discharged from the ED with a diagnosis of headache, the rate of SNNDs identified within 30 days of the initial visit was 0.5%. Overall, there was a low incidence of high-acuity disease. Patients found to have SNNDs underwent more diagnostic testing at the index visits compared with patients without SNNDs, suggesting high initial clinical suspicion. For the subset of patients with clinical suspicion for serious etiologies but none identified at the index visit, this represents an opportunity for close outpatient follow-up.

Dr Zhou designed the study, analyzed and interpreted the data, drafted the initial manuscript, and approved the final manuscript as submitted; Dr Marin designed the study, supervised the data analysis and interpretation, reviewed and revised the manuscript, and approved the final manuscript as drafted; Dr Hickey conceptualized the study, supervised the data analysis and interpretation, reviewed and revised the manuscript, and approved the final manuscript as drafted; Dr Ramgopal conceptualized and designed the study, analyzed and interpreted the data, reviewed and revised the manuscript, and approved the final manuscript as drafted; and all authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.

FUNDING: No external funding.

CCC

complex chronic condition

CSF

cerebrospinal fluid

CT

computed tomography

ED

emergency department

ICD-10-CM

International Classification of Diseases, 10th Revision, Clinical Modification

PHIS

Pediatric Health Information System

SNND

serious neurologic and nonneurologic diagnosis

1
Krogh
AB
,
Larsson
B
,
Linde
M
.
Prevalence and disability of headache among Norwegian adolescents: a cross-sectional school-based study
.
Cephalalgia
.
2015
;
35
(
13
):
1181
1191
2
Abu-Arafeh
I
,
Razak
S
,
Sivaraman
B
,
Graham
C
.
Prevalence of headache and migraine in children and adolescents: a systematic review of population-based studies
.
Dev Med Child Neurol
.
2010
;
52
(
12
):
1088
1097
3
Straube
A
,
Heinen
F
,
Ebinger
F
,
von Kries
R
.
Headache in school children: prevalence and risk factors
.
Dtsch Arztebl Int
.
2013
;
110
(
48
):
811
818
4
Woods
K
,
Ostrowski-Delahanty
S
,
Cieplinski
T
,
Winkelman
J
,
Polk
P
,
Victorio
MC
.
Psychosocial and demographic characteristics of children and adolescents with headache presenting for treatment in a headache infusion center
.
Headache
.
2019
;
59
(
6
):
858
868
5
Hong
A
,
Shah
Y
,
Singh
K
,
Karkare
S
,
Kothare
S
.
Characteristics and predictors of 7- and 30-day hospital readmissions to pediatric neurology
.
Neurology
.
2019
;
92
(
16
):
e1926
e1932
6
Kabbouche
MA
,
Linder
SL
.
Management of migraine in children and adolescents in the emergency department and inpatient setting
.
Curr Pain Headache Rep
.
2005
;
9
(
5
):
363
367
7
Kabbouche
M
.
Pediatric inpatient headache therapy: what is available
.
Headache
.
2015
;
55
(
10
):
1426
1429
8
Perry
MC
,
Yaeger
SK
,
Toto
RL
,
Suresh
S
,
Hickey
RW
.
A modern epidemic: increasing pediatric emergency department visits and admissions for headache
.
Pediatr Neurol
.
2018
;
89
:
19
25
9
Kan
L
,
Nagelberg
J
,
Maytal
J
.
Headaches in a pediatric emergency department: etiology, imaging, and treatment
.
Headache
.
2000
;
40
(
1
):
25
29
10
Massano
D
,
Julliand
S
,
Kanagarajah
L
, et al
.
Headache with focal neurologic signs in children at the emergency department
.
J Pediatr
.
2014
;
165
(
2
):
376
382
11
Burton
LJ
,
Quinn
B
,
Pratt-Cheney
JL
,
Pourani
M
.
Headache etiology in a pediatric emergency department
.
Pediatr Emerg Care
.
1997
;
13
(
1
):
1
4
12
Scagni
P
,
Pagliero
R
.
Headache in an Italian pediatric emergency department
.
J Headache Pain
.
2008
;
9
(
2
):
83
87
13
Conicella
E
,
Raucci
U
,
Vanacore
N
, et al
.
The child with headache in a pediatric emergency department
.
Headache
.
2008
;
48
(
7
):
1005
1011
14
Rossi
R
,
Versace
A
,
Lauria
B
, et al
.
Headache in the pediatric emergency department: a 5-year retrospective study
.
Cephalalgia
.
2018
;
38
(
11
):
1765
1772
15
Glatstein
M
,
Voliovitch
Y
,
Orbach
R
, et al
.
Outpatient management of headache after pediatric emergency department visit: are we missing anything?
Headache
.
2019
;
59
(
9
):
1530
1536
16
Lewis
DW
,
Ashwal
S
,
Dahl
G
, et al;
Quality Standards Subcommittee of the American Academy of Neurology
;
Practice Committee of the Child Neurology Society
.
Practice parameter: evaluation of children and adolescents with recurrent headaches: report of the Quality Standards Subcommittee of the American Academy of Neurology and the Practice Committee of the Child Neurology Society
.
Neurology
.
2002
;
59
(
4
):
490
498
17
Pektezel
MY
,
Konuskan
B
,
Sonmez
FM
,
Oguz
KK
,
Anlar
B
.
Pediatric headache and neuroimaging: experience of two tertiary centers
.
Childs Nerv Syst
.
2020
;
36
(
1
):
173
177
18
Raucci
U
,
Della Vecchia
N
,
Ossella
C
, et al
.
Management of childhood headache in the emergency department. review of the literature
.
Front Neurol
.
2019
;
10
:
886
19
Sheridan
DC
,
Meckler
GD
,
Spiro
DM
,
Koch
TK
,
Hansen
ML
.
Diagnostic testing and treatment of pediatric headache in the emergency department
.
J Pediatr
.
2013
;
163
(
6
):
1634
1637
20
Khullar
D
,
Jha
AK
,
Jena
AB
.
Reducing diagnostic errors–why now?
N Engl J Med
.
2015
;
373
(
26
):
2491
2493
21
Hussain
F
,
Cooper
A
,
Carson-Stevens
A
, et al
.
Diagnostic error in the emergency department: learning from national patient safety incident report analysis
.
BMC Emerg Med
.
2019
;
19
(
1
):
77
22
Chellis
M
,
Olson
J
,
Augustine
J
,
Hamilton
G
.
Evaluation of missed diagnoses for patients admitted from the emergency department
.
Acad Emerg Med
.
2001
;
8
(
2
):
125
130
23
Mackay
MT
,
Chua
ZK
,
Lee
M
, et al
.
Stroke and nonstroke brain attacks in children
.
Neurology
.
2014
;
82
(
16
):
1434
1440
24
Dubosh
NM
,
Edlow
JA
,
Goto
T
,
Camargo
CA
 Jr.
,
Hasegawa
K
.
Missed serious neurologic conditions in emergency department patients discharged with nonspecific diagnoses of headache or back pain
.
Ann Emerg Med
.
2019
;
74
(
4
):
549
561
25
Centers for Disease Control and Prevention
.
International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM). Available at: https://www.cdc.gov/nchs/icd/icd10cm.htm. Accessed January 22, 2020
26
Feudtner
C
,
Feinstein
JA
,
Zhong
W
,
Hall
M
,
Dai
D
.
Pediatric complex chronic conditions classification system version 2: updated for ICD-10 and complex medical technology dependence and transplantation
.
BMC Pediatr
.
2014
;
14
:
199
27
Wilne
S
,
Collier
J
,
Kennedy
C
,
Koller
K
,
Grundy
R
,
Walker
D
.
Presentation of childhood CNS tumours: a systematic review and meta-analysis
.
Lancet Oncol
.
2007
;
8
(
8
):
685
695
28
Reulecke
BC
,
Erker
CG
,
Fiedler
BJ
,
Niederstadt
T-U
,
Kurlemann
G
.
Brain tumors in children: initial symptoms and their influence on the time span between symptom onset and diagnosis
.
J Child Neurol
.
2008
;
23
(
2
):
178
183
29
Papetti
L
,
Capuano
A
,
Tarantino
S
,
Vigevano
F
,
Valeriani
M
.
Headache as an emergency in children and adolescents
.
Curr Pain Headache Rep
.
2015
;
19
(
3
):
3
30
Schobitz
E
,
Qureshi
F
,
Lewis
D
.
Pediatric headaches in the emergency department
.
Curr Pain Headache Rep
.
2006
;
10
(
5
):
391
396
31
Whelton
PK
,
Carey
RM
,
Aronow
WS
, et al
.
2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APHA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American college of cardiology/american heart association task force on clinical practice guidelines
.
Hypertension
.
2018
;
71
(
6
):
e13
e115
32
Siu
AL
;
U.S. Preventive Services Task Force
.
Screening for high blood pressure in adults: U.S. Preventive Services Task Force recommendation statement
.
Ann Intern Med
.
2015
;
163
(
10
):
778
786
33
Dionne
JM
.
Updated guideline may improve the recognition and diagnosis of hypertension in children and adolescents; review of the 2017 AAP blood pressure clinical practice guideline
.
Curr Hypertens Rep
.
2017
;
19
(
10
):
84
34
Gorelick
MH
,
Knight
S
,
Alessandrini
EA
, et al;
Pediatric Emergency Care Applied Research Network
.
Lack of agreement in pediatric emergency department discharge diagnoses from clinical and administrative data sources
.
Acad Emerg Med
.
2007
;
14
(
7
):
646
652
35
Athey
J
,
Dean
JM
,
Ball
J
,
Wiebe
R
,
Melese-d’Hospital
I
.
Ability of hospitals to care for pediatric emergency patients
.
Pediatr Emerg Care
.
2001
;
17
(
3
):
170
174
36
Larson
DB
,
Johnson
LW
,
Schnell
BM
,
Goske
MJ
,
Salisbury
SR
,
Forman
HP
.
Rising use of CT in child visits to the emergency department in the United States, 1995-2008
.
Radiology
.
2011
;
259
(
3
):
793
801
37
Michelson
KA
,
Lyons
TW
,
Hudgins
JD
, et al
.
Use of a national database to assess pediatric emergency care across United States emergency departments
.
Acad Emerg Med
.
2018
;
25
(
12
):
1355
1364
38
Alpern
ER
,
Clark
AE
,
Alessandrini
EA
, et al;
Pediatric Emergency Care Applied Research Network (PECARN)
.
Recurrent and high-frequency use of the emergency department by pediatric patients
.
Acad Emerg Med
.
2014
;
21
(
4
):
365
373
39
Supat
B
,
Brennan
JJ
,
Vilke
GM
,
Ishimine
P
,
Hsia
RY
,
Castillo
EM
.
Characterizing pediatric high frequency users of California emergency departments
.
Am J Emerg Med
.
2019
;
37
(
9
):
1699
1704

Competing Interests

POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose.

FINANCIAL DISCLOSURE: The authors have indicated they have no financial relationships relevant to this article to disclose.

Supplementary data