Paediatric ischaemic stroke is a valid diagnosis in the Swedish National Patient Register

Risk factors for pediatric ischemic stroke and intracranial hemorrhage: A national electronic health record based study

Background

Stroke is an important cause of morbidity in pediatrics. Large studies are needed to better understand the epidemiology, pathogenesis and risk factors associated with pediatric stroke. Large administrative datasets can provide information on risk factors in perinatal and childhood stroke at low cost. The aim of this hypothesis-generating study was to use a large administrative dataset to assess for prevalence and odds-ratios of rare exposures associated with pediatric stroke.

Methods

The data for patients aged 0-18 with a diagnosis of either ischemic stroke or intracranial hemorrhage were extracted from the Cerner Health Facts EMR Database from 2000 to 2018. Prevalence of various possible risk factors for pediatric and adult stroke was assessed using ICD 9 and 10 codes. Odds ratios were calculated using a control group of patients without stroke.

Results

10,688 children were identified with stroke. 6339 (59 %) were ischemic and 4349 (41 %) were hemorrhagic. The most frequently identified risk factors for ischemic stroke across age groups were hypertension (29-44 %), trauma (19-33 %), and malignancy (11-24 %). The most common risk factors seen with hemorrhagic stroke were trauma (32-64 %), malignancy (5-19 %) and arrhythmia (9-12 %). Odds ratios across all age groups for dyslipidemia (17-64), hypertension (20-63), and tobacco exposure (3-59) were high in the ischemic stroke cohort.

Conclusion

This is the largest retrospective study of pediatric stroke of its kind from hospitals across the US in both academic and non-academic clinical settings. Much of our data was consistent with prior studies. ICD codes for tobacco exposure, hyperlipidemia, diabetes, and hypertension all had high odds ratios for stroke in children, which suggest a relationship between these conditions and pediatric stroke. However, ascertainment bias is a major concern with electronic health record-based studies. More focused study is needed into the role of these exposures into the pathogenesis of pediatric stroke.

The Positive Predictive Value of Pediatric Stroke Diagnoses in Administrative Data: A Retrospective Validation Study

Background

This retrospective cohort study aimed to examine the positive predictive value (PPV) of pediatric stroke diagnoses in the Danish National Registry of Patients (DNRP) and the impact of different stroke definitions on the PPV.

Methods

We included children registered with a stroke or stroke-related diagnosis in the DNRP between January 2017 through December 2020. Two assessors reviewed medical records and validated cases according to the American Heart and American Stroke Association (AHA/ASA) stroke definition. The level of interrater agreement was examined using kappa statistics. Validation by the AHA/ASA definition was compared with validation according to the definition in the International Classification of Disease 11th version (ICD-11) and the World Health Organization's definition.

Results

Stroke was confirmed in 120 of 309 included children, yielding an overall PPV of 0.39 (95% CI: 0.33-0.45). PPV varied across stroke subtypes from 0.83 (95% CI: 0.71-0.92) for ischemic stroke (AIS), 0.57 (95% CI: 0.37-0.76) for unspecified stroke, 0.42 (95% CI: 0.33-0.52) for intracerebral hemorrhage (ICH) to 0.31 (95% CI: 0.55-0.98) and 0.07 (95% CI: 0.01-0.22) for cerebral venous thrombosis and subarachnoid hemorrhage (SAH), respectively. Most non-confirmed ICH and SAH diagnoses were in children with traumatic intracranial hemorrhages (36 and 66% respectively). Among 70 confirmed AIS cases, 25 (36%) were identified in non-AIS code groups. PPV varied significantly across stroke definitions with the highest for the AHA/ASA definition (PPV = 0.39, 95% CI: 0.34-0.45) and the lowest for the WHO definition (PPV = 0.29, 95% CI: 0.24-0.34). Correspondingly, the incidence of pediatric AIS per 100.000 person-years changed from 1.5 for the AHA/ASA definition to 1.2 for ICD-11 and 1.0 for the WHO-definition. The overall interrater agreement was considered excellent (κ=0.85).

Conclusion

After validation, stroke was confirmed in only half of the children registered in the DNRP with a stroke-specific diagnosis. Non-validated administrative data should be used with caution in pediatric stroke research. Pediatric stroke incidence rates may vary markedly depending on which stroke definition is used.

A National, Electronic Health Record-Based Study of Perinatal Hemorrhagic and Ischemic Stroke

BACKGROUND

Perinatal stroke occurs in approximately 1 in 1100 live births. Large electronic health record (EHR) data can provide information on exposures associated with perinatal stroke in a larger number of patients than is achievable through traditional clinical studies. The objective of this study is to assess prevalence and odds ratios of known and theorized comorbidities with perinatal ischemic and hemorrhagic stroke.

METHODS

The data for patients aged 0-28 days with a diagnosis of either ischemic or hemorrhagic stroke were extracted from the Cerner Health Facts Electronic Medical Record (EMR) database. Incidence of birth demographics and perinatal complications were recorded. Odds ratios were calculated against a control group.

RESULTS

A total of 535 (63%) neonates were identified with ischemic stroke and 312 (37%) with hemorrhagic stroke. The most common exposures for ischemic stroke were sepsis (n = 82, 15.33%), hypoxic injury (n = 61, 11.4%), and prematurity (n = 49, 9.16%). The most common comorbidities for hemorrhagic stroke were prematurity (n = 81, 26%) and sepsis (n = 63, 20%). No perinatal ischemic stroke patients had diagnosis codes for cytomegalovirus disease. Procedure and diagnosis codes related to critical illness, including intubation and resuscitation, were prominent in both hemorrhagic (n = 46, 15%) and ischemic stroke (n = 45, 8%).

CONCLUSION

This electronic health record-based study of perinatal stroke, the largest of its kind, demonstrated a wide variety of comorbid conditions with ischemic and hemorrhagic stroke. Sepsis, prematurity, and hypoxic injury are associated with perinatal hemorrhagic and ischemic stroke, though prevalence varies between types. Much of our data were similar to prior studies, which lends validity to the electronic health record database in studying perinatal stroke.

Risk of Autism After Pediatric Ischemic Stroke: A Nationwide Cohort Study

BACKGROUND AND OBJECTIVES

Ischemic stroke increases the risk of neurodevelopmental disorders; however, the risk of autism is not thoroughly explored. Our aim was to evaluate risk of autism and risk factors for autism in children with pediatric ischemic stroke and in their first-degree relatives.

METHODS

In this cohort study, individuals with ischemic stroke from 1969 to 2016, <18 years of age, alive 1 week after stroke, and without prior autism were identified in Swedish national registers. Ten matched controls per index individual and all first-degree relatives of index individuals and controls were identified. Conditional Cox regression was used to calculate the risk of autism. Unconditional logistic regression was performed to analyze sex, gestational age, age at stroke diagnoses, comorbid adverse motor outcome, comorbid epilepsy, and a sibling with autism as risk factors for autism in children with ischemic stroke.

RESULTS

Of the 1,322 index individuals, 46 (3.5%) were diagnosed with autism compared to 161 (1.2%) controls (adjusted hazard ratio [aHR] 3.02, 95% CI 2.15-4.25). There was no significant difference in risk of autism according to age at stroke: perinatal (aHR 2.69, 95% CI 1.44-5.03) and childhood stroke (aHR 3.18, 95% CI 2.12-4.78). The increased risk remained after exclusion of children born preterm or small for gestational age (aHR 3.78, 95% CI 2.55-5.60) and when children with stroke diagnosed from 1997 to 2014 were analyzed (aHR 2.91, 95% CI = 1.95-4.35). Compared to controls, the risk of autism was increased in individuals with ischemic stroke and comorbid epilepsy (aHR 7.05, 95% CI 3.74-13.30), as well as adverse motor outcome (aHR 4.28, 95% CI 2.44-7.51). When individuals with adverse motor outcome and epilepsy were censored, the risk of autism was still increased (aHR 2.37, 95% CI 1.45-3.85). Sex, gestational age, and having a sibling with autism were not associated with autism in individuals with pediatric ischemic stroke.

DISCUSSION

An increased risk of autism was seen after pediatric ischemic stroke, particularly in individuals with comorbid epilepsy, and could not be explained by being born preterm or small for gestational age. The risk was increased also in individuals free from epilepsy and adverse motor outcome, implying that all children with ischemic stroke should be readily screened for autism if the disorder is suspected.

Adverse motor outcome after paediatric ischaemic stroke: A nationwide cohort study

BACKGROUND

Various frequencies of adverse motor outcomes (cerebral palsy and hemiplegia) after paediatric ischaemic stroke have been reported. Few reports on the risks of adverse motor outcomes in nationwide cohorts and contributing risk factors are available.

OBJECTIVES

To assess risk of adverse motor outcome and potential risk factors thereof after paediatric ischaemic stroke in a nationwide cohort.

METHODS

This nationwide matched cohort study identified 877 children <18 years of age diagnosed with ischaemic stroke through the Swedish national health registers from 1997 to 2016. These children, exposed to ischaemic stroke, alive 1 week after stroke, were matched for age, sex and county of residence with 10 unexposed children. Using Cox regression, we estimated the risk of adverse motor outcomes in children with stroke compared to that in unexposed children. Logistic regression was applied to compare the characteristics of children with and without adverse motor outcomes after stroke.

RESULTS

Out of the 877 children with ischaemic stroke, 280 (31.9%) suffered adverse motor outcomes compared with 21 (0.2%) of the 8770 unexposed: adjusted hazard ratio (aHR) 167.78 (95% confidence interval (CI) 107.58, 261.66). There were no differences between risk estimates of adverse motor outcome according to age at stroke: perinatal stroke (aHR 124.11, 95% CI 30.45, 505.84) and childhood stroke (aHR 182.37, 95% CI 113.65, 292.64). An association between adverse motor outcome and childhood stroke aOR 1.56 (95% CI 1.05, 2.31) was found when analysing only children with ischaemic stroke. No associations were found between adverse motor outcome and sex, gestational age or parental age at birth.

CONCLUSIONS

The risk of adverse motor outcome is substantial after paediatric ischaemic stroke, especially childhood stroke, confirming results of previous smaller studies. This study found no associations between sex, gestational age or parental age and adverse motor outcome after paediatric ischaemic stroke.

Long-Term Mortality in Children With Ischemic Stroke: A Nationwide Register-Based Cohort Study

BACKGROUND AND PURPOSE

Ischemic stroke is a common cause of death in adults, however, mortality after pediatric ischemic stroke is not well explored. We investigate long-term and cause-specific mortality in children with ischemic stroke and their first-degree relatives.

METHODS

Through nationwide Swedish registers, we identified 1606 individuals <18 years old with ischemic stroke between 1969 and 2016 and their first-degree relatives (n=5714). Each individual with ischemic stroke was compared with 10 reference individuals (controls) matched for age, sex, and county of residence. Our main analysis examined 1327 children with ischemic stroke still alive 1 week after the event. First-degree relatives to children with ischemic stroke were compared with first-degree relatives to the reference individuals. Using a Cox proportional hazard regression model, the risk of overall and cause-specific mortality was computed in individuals with pediatric ischemic stroke and their first-degree relatives.

RESULTS

The mortality rate in the first 6 months was 40.1 (95% CI, 24.7-55.6) per 1000 person-years compared with 1.1/1000 in controls (95% CI, 0.3-1.9). The overall mortality risk was hazard ratio (HR)=10.8 (95% CI, 8.1-14.3) and remained elevated beyond 20 years (HR=3.9 [95% CI, 2.1-7.1]). Children with ischemic stroke were at increased risk of death from neurological diseases (HR=29.9 [95% CI, 12.7-70.3]), cardiovascular diseases (HR=6.2 [95% CI, 1.8-22.2]), cancers (HR=6.5 [95% CI, 2.6-15.9]) and endocrine, nutritional and metabolic diseases (HR=49.2 [95% CI, 5.7-420.8]). First-degree relatives to children with ischemic stroke had an increased mortality risk (HR=1.21 [95% CI, 1.05-1.39]), with the highest risk among siblings (HR=1.52 [95% CI, 1.09-2.11]) and relatives to individuals with ischemic stroke >28 days of age (HR=1.23 [95% CI, 1.06-1.42]) compared with the relatives of the controls.

CONCLUSIONS

Long-term mortality increased after pediatric ischemic stroke, even 20 years later, with neurological diseases as the most frequent cause of death.

Pediatric Ischemic Stroke and Epilepsy: A Nationwide Cohort Study

Background and Purpose

The risk of epilepsy after stroke has not been thoroughly explored in pediatric ischemic stroke. We examined the risk of epilepsy in children with ischemic stroke as well as in their first-degree relatives.

Methods

In Swedish National Registers, we identified 1220 children <18 years with pediatric ischemic stroke diagnosed 1969 to 2016, alive 7 days after stroke and with no prior epilepsy. We used 12 155 age- and sex-matched individuals as comparators. All first-degree relatives to index individuals and comparators were also identified. The risk of epilepsy was estimated in children with ischemic stroke and in their first-degree relatives using Cox proportional hazard regression model.

Results

Through this nationwide population-based study, 219 (18.0%) children with ischemic stroke and 91 (0.7%) comparators were diagnosed with epilepsy during follow-up corresponding to a 27.8-fold increased risk of future epilepsy (95% CI, 21.5–36.0). The risk of epilepsy was still elevated after 20 years (hazard ratio [HR], 7.9 [95% CI, 3.3–19.0]), although the highest HR was seen in the first 6 months (HR, 119.4 [95% CI, 48.0–297.4]). The overall incidence rate of epilepsy was 27.0 per 100 000 person-years (95% CI, 21.1–32.8) after ischemic stroke diagnosed ≤day 28 after birth (perinatal) and 11.6 per 100 000 person-years (95% CI, 9.6–13.5) after ischemic stroke diagnosed ≥day 29 after birth (childhood). Siblings and parents, but not offspring, to children with ischemic stroke were at increased risk of epilepsy (siblings: HR, 1.64 [95% CI, 1.08–2.48] and parents: HR, 1.41 [95% CI, 1.01–1.98]).

Conclusions

The risk of epilepsy after ischemic stroke in children is increased, especially after perinatal ischemic stroke. The risk of epilepsy was highest during the first 6 months but remained elevated even 20 years after stroke which should be taken into account in future planning for children affected by stroke.