Transient Ischemic Attack Requiring Hospitalization of Children in the United States
Kids’ Inpatient Database 2003 to 2009
Background and Purpose—Transient ischemic attacks (TIA) are not well described in children. We assessed the prevalence of risk factors for TIA requiring hospitalization in children in a large national database.
Methods—Using the Healthcare Cost and Utilization Project Kids’ Inpatient Database, children aged 1 to 18 years admitted for TIA in 2003, 2006, and 2009 were identified by International Classification of Diseases, Ninth Revision, Clinical Modification code 435. Descriptive analyses identified patient characteristics. Trend analysis determined the change in annual average hospitalization days from 2003 to 2009.
Results—TIA was the primary diagnosis for 531 children. Important secondary diagnoses included sickle cell disease (20%), congenital heart disease (11%), migraine (12%), moyamoya disease (10%), and stroke (4%). Mean length of stay decreased from 3.0 days (95% confidence interval, 2.4–3.6) in 2003 to 2.3 days (95% confidence interval, 2.0–2.7) in 2009 (P=0.04). During the same period, 2590 children were admitted with ischemic stroke; 4.8 children with stroke were admitted for every child with TIA.
Conclusions—Recognized risk factors for TIA, including sickle cell disease, congenital heart disease, moyamoya, recent stroke, and migraine, were present in <60% of children. Pediatric admissions for ischemic stroke were ≈5-fold more common than for TIA. Further study is required to understand the risk of stroke after TIA in children to guide appropriate evaluation and treatment.
Transient ischemic attack (TIA) has rarely been described in children. The Brain Attack Surveillance in Corpus Christi project found an approximate annual incidence of hemorrhagic or ischemic stroke in children of 4.3 per 100 000 and of 0.54 per 100 000 for TIA in a population-based sample of 8 children with stroke or TIA.1 In adults, depending on risk factors, 1% to 10% with TIA will have an ischemic stroke within 2 days.2 However, the growing literature on TIA in adults does not apply to children who typically have different risk factors. This is a first step to understand the epidemiology and medical conditions associated with TIA in children.
The patient sample was taken from the Kids’ inpatient database, part of the Healthcare Cost and Utilization Project (HCUP). A comprehensive synopsis of Kids’ inpatient database is available at http://www.hcup-us.ahrq.gov/kidoverview.jsp.
National estimates were obtained by use of discharge weights developed using the American Hospital Association as the standard. Children aged 1 to 18 years from Kids’ inpatient database years 2003, 2006, and 2009 were included in this study. The International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) primary diagnosis code 435 identified children admitted with TIA. Variables including age, sex, race/ethnicity, and comorbidities were obtained from Agency for Healthcare Research and Quality’s comorbidity data files. ICD-9-CM secondary diagnosis codes identified secondary diagnoses in children with TIA including but not limited to hypertension (401, 405), elevated blood pressure (796.2), diabetes mellitus (249, 250), congenital heart disease (745–747), migraine (346), moyamoya disease (MMD; 437.5), stroke (430–434, 436–437.1), and sickle cell disease (SCD; 282.6). ICD-9-CM procedure codes were used to estimate the percentage of patients with TIA who underwent TIA-related procedures, such as cerebral angiography (88.41) and transfusion (99.04). Length of stay (LOS) and hospital charges were recorded. If there were <11 discharges for a given variable, that variable was excluded according to the HCUP policy.
Linear regression determined the relationship between hospitalization charges and LOS after adjusting for hospitalization year to control for inflation of hospital charges. Trend analysis was performed to determine the change in annual average hospitalization days from 2003 through 2009 using the Cochran–Armitage trend test. SAS version 9.3 software (SAS Institute, Cary, NC) was used to perform analyses.
TIA was the primary hospitalization diagnosis in 531 children (Table I in the online-only Data Supplement). Median age was 13 (interquartile range, 8–16) years, and 48% were male. TIAs were more common in adolescents; 67% occurred in those aged 11 to 18 years. Important secondary diagnoses included SCD (20%), congenital heart disease (11%), migraine (12%), MMD (10%), and stroke during the same hospital admission (4%). Of these children with both TIA and stroke, 17 of 22 had identifiable risk factors: 10 had SCD, 5 had MMD and 2 had migraine. Anemia, coagulopathy, diabetes mellitus, hypertension, and obesity were rare comorbid conditions, each noted in ≤6% of children. Two hundred seventeen (41%) had no risk factor identified. Additional analyses are available in Tables II and III in the online-only Data Supplement. The rates of cerebral angiography and transfusion were 18% and 7%, respectively. No child with TIA died; 97% were discharged home.
Mean LOS decreased from 3.0 days (95% confidence interval, 2.4–3.6) in 2003 to 2.3 days (95% confidence interval, 2.0–2.7) in 2009 (P<0.04). Hospitalization charges were directly associated with LOS (P<0.0001) even after adjusting for hospitalization year. During the same period, 2590 children were admitted with arterial ischemic stroke (AIS); therefore, 4.8 children with AIS were admitted for every child with TIA.
In recent years, although research has focused on childhood AIS,3 few studies have described TIA in a pediatric population. In adults with TIA, 1% to 10% will have a stroke within the next 48 hours,2 and up to 15% will have a stroke within 3 months.4 In this 3-year sample of >500 children hospitalized with a primary diagnosis of TIA, 22 (4%) had a secondary diagnosis of stroke within the same hospitalization.
TIAs were more common in adolescents with 67% occurring in those aged 11 to 18 years. Of note, stroke was ≈5 times more common than TIA in the Kids’ database. Although the frequency of stroke after a TIA in children has not been reported, about a third of children who had a confirmed AIS had a history of recent TIAs,5 and prior TIA is a strong risk factor for recurrent stroke in children.6
Similar to our study, the sparse pediatric TIA literature has primarily included children with MMD and children with SCD. In the Cooperative Study of Sickle Cell Disease, a history of TIA was a strong risk factor for AIS.7 In young children with MMD, the most common presenting symptom is TIA.8
In our study, of 531 children with TIA, 217 (40.9%) had no risk factor identified. This is consistent with pediatric AIS literature where up to 30% of strokes remain cryptogenic even after a complete vascular, cardiac, and prothrombotic evaluation.3
This study has limitations inherent to the Kids’ data set, namely the accuracy of the diagnosis and procedures codes listed in the discharge summaries. In a previous study, the sensitivity and positive predictive values in adults for a primary diagnosis of ICD-9-CM code 435, TIA, were 75% and 80%, respectively.9 It is also likely that TIA is underdiagnosed in children. Without detailed chart review, it is difficult to determine whether migraine is a risk factor for TIA and stroke in children as it is in adults or whether complicated migraine is simply a common differential diagnosis for TIA in children.10 Definitively distinguishing whether children with a primary diagnosis of TIA had stroke or migraine before TIA or after TIA is not possible in this administrative data set. Finally, application of the diagnosis TIA might not be uniform across all hospitals.
Recognized risk factors for TIA including SCD, congenital heart disease, MMD, recent stroke, and migraine were present in <60% of children. Admissions for AIS were ≈5-fold more common than for TIA in children, and 4% with a primary diagnosis of TIA also had stroke during the same hospitalization. Children in this high-risk category often had SCD or MMD. Children with TIA may also be quite healthy: LOS was short, no child died, and most were discharged home rather than to a rehabilitation facility. Additional study is required to understand the risk of stroke after TIA in children to guide appropriate evaluation and treatment.
Sources of Funding
Dr Qureshi received research grant from National Institutes of Health (NIH)-U01-NS062091-01A2; Dr Beslow from NIH-K12-NS049453; and Dr Jordan from NIH-K23-NS062110.
The online-only Data Supplement is available with this article at http://stroke.ahajournals.org/lookup/suppl/doi:10.1161/STROKEAHA.113.004526/-/DC1.
- Received December 13, 2013.
- Revision received December 30, 2013.
- Accepted January 2, 2014.
- © 2014 American Heart Association, Inc.
- Zahuranec DB,
- Brown DL,
- Lisabeth LD,
- Morgenstern LB
- Roach ES,
- Golomb MR,
- Adams R,
- Biller J,
- Daniels S,
- Deveber G,
- et al
- Easton JD,
- Saver JL,
- Albers GW,
- Alberts MJ,
- Chaturvedi S,
- Feldmann E,
- et al
- Ganesan V,
- Prengler M,
- Wade A,
- Kirkham FJ
- Ohene-Frempong K,
- Weiner SJ,
- Sleeper LA,
- Miller ST,
- Embury S,
- Moohr JW,
- et al
- Tagawa T,
- Naritomi H,
- Mimaki T,
- Yabuuchi H,
- Sawada T