Accuracy of ICD-9 codes for identifying children with cerebral sinovenous thrombosis
ABSTRACT Childhood sinovenous thrombosis is rare, making it difficult to study; International Classification of Diseases, ninth revision (ICD-9), code searches across multiple hospitals would permit the identification of large numbers of children with sinovenous thrombosis. However, the accuracy of these codes for identifying childhood sinovenous thrombosis has not been established. We performed a retrospective search of admissions records for Riley Hospital for Children in Indianapolis, Indiana, from January 1999 to June 2005 using ICD-9 codes 325 (cerebral sinovenous thrombosis, excluding nonpyogenic cases and cases associated with pregnancy and the puerperium), 437.6 (cerebral venous thrombosis of nonpyogenic origin), and 671.5 (cerebral venous thrombosis in pregnancy or the puerperium) in any position. During this period, there were 47042 admissions. ICD-9 code 325 identified 61 admissions on 56 children. Only 13% were of pyogenic origin. Fifty-two (92.9%) had "possible, probable, or definite" sinovenous thrombosis, but only 76.9% of those had "probable or definite" sinovenous thrombosis. Uncertainty in diagnoses stemmed from limitations in imaging and disagreement over interpretation of imaging studies. ICD-9 code 325 in the primary position identified 7 children; all had possible (n = 1), probable (n = 1), or definite (n = 5) sinovenous thrombosis. ICD-9 code 437.6 identified a single admission on a single case of probable cerebral venous thrombosis; it was unclear whether this case was "nonpyogenic." ICD-9 code 671.5 did not identify any children. ICD-9 code 325 is useful for identifying children likely to have sinovenous thrombosis, but it is not useful for differentiating pyogenic and nonpyogenic cases, and uncertainty in clinical diagnosis makes it difficult to gauge the true accuracy. Furthermore, it is important to search for the code in any position as limiting searches to the primary position misses most cases.
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ABSTRACT: IMPORTANCE Hematoma expansion is the only modifiable predictor of outcome in adult intracerebral hemorrhage; however, the frequency and clinical significance of hematoma expansion after childhood intracerebral hemorrhage are unknown. OBJECTIVE To assess the frequency and extent of hematoma expansion in children with nontraumatic intracerebral hemorrhage. DESIGN, SETTING, AND PARTICIPANTS Prospective observational cohort study at 3 tertiary care pediatric hospitals. Children (≥37 weeks' gestation to 18 years) with nontraumatic intracerebral hemorrhage were enrolled in a study from 2007 to 2012 focused on predictors of outcome. For this planned substudy of hematoma expansion, neonates 28 days or younger and participants with isolated intraventricular hemorrhage were excluded. Children with 2 head computed tomography (CT) scans within 48 hours were evaluated for hematoma expansion and were compared with children with only 1 head CT scan. Consent for the primary cohort was obtained from 73 of 87 eligible participants (84%); 41 of 73 children enrolled in the primary cohort met all inclusion/exclusion criteria for this substudy, in whom 22 had 2 head CT scans obtained within 48 hours that could be evaluated for hematoma expansion. Within our substudy cohort, 21 of 41 (51%) were male, 25 of 41 (61%) were white, 16 of 41 (39%) were black, and median age was 7.7 years (interquartile range, 2.0-13.4 years). MAIN OUTCOME AND MEASURE Primary outcome was prevalence of hematoma expansion. RESULTS Of 73 children, 41 (56%) met inclusion criteria, and 22 (30%) had 2 head CT scans to evaluate expansion. Among these 22 children, median time from symptom onset to first CT was 2 hours (interquartile range, 1.3-6.5 hours). Median baseline hemorrhage volume was 19.5 mL, 1.6% of brain volume. Hematoma expansion occurred in 7 of 22 (32%). Median expansion was 4 mL (interquartile range, 1-11 mL). Three children had significant (>33%) expansion; 2 required urgent hematoma evacuation. Expansion was not associated with poorer outcome. Compared with children with only 1 head CT scan within 48 hours, children with 2 head CT scans had larger baseline hemorrhage volumes (P = .05) and were more likely to receive treatment for elevated intracranial pressure (P < .001). CONCLUSIONS AND RELEVANCE Hematoma expansion occurs in children with intracerebral hemorrhage and may require urgent treatment. Repeat CT should be considered in children with either large hemorrhage or increased intracranial pressure.12/2013; 71(2). DOI:10.1001/jamaneurol.2013.4672
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ABSTRACT: Observational database research frequently relies on imperfect administrative markers to determine comorbid status, and it is difficult to infer to what extent the associated misclassification impacts validity in multivariable analyses. The effect that imperfect markers of disease will have on validity in situations in which researchers attempt to match populations that have strong baseline health differences is underemphasized as a limitation in some otherwise high-quality observational studies. The present simulations were designed as a quantitative demonstration of the importance of this common and underappreciated issue. Two groups of Monte Carlo simulations were performed. The first demonstrated the degree to which controlling for a series of imperfect markers of disease between different populations taking 2 hypothetically harmless drugs would lead to spurious associations between drug assignment and mortality. The second Monte Carlo simulation applied this principle to a recent study in the field of anesthesiology that purported to show increased perioperative mortality in patients taking metoprolol versus atenolol. None. Simulation 1: High type-1 error (ie, false positive findings of an independent association between drug assignment and mortality) was observed as sensitivity and specificity declined and as systematic differences in disease prevalence increased. Simulation 2: Propensity score matching across several imperfect markers was unlikely to eliminate important baseline health disparities in the referenced study. In situations in which large baseline health disparities exist between populations, matching on imperfect markers of disease may result in strong bias away from the null hypothesis.Journal of cardiothoracic and vascular anesthesia 08/2013; DOI:10.1053/j.jvca.2013.03.014 · 1.06 Impact Factor
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ABSTRACT: Adult survivors of childhood cancer have an increased risk of cerebrovascular disease; little is known about early stroke risk in childhood cancer. Our objectives were to assess stroke prevalence in children with cancer, to establish cancer and stroke type, and to determine if modifiable risk factors for stroke were present. Children with stroke and cancer were compared with all children seen for cancer at a single institution between 2000 and 2009. An International Classification of Disease, 9th version, code search and search of existing pediatric oncology and stroke databases identified children <18 years with ischemic stroke, intracerebral hemorrhage, and cerebral sinovenous thrombosis. Of 1411 children with cancer, 15 had a stroke (1.1%, 95% CI: 0.6-1.7%). Stroke classifications were seven intracerebral hemorrhages, five ischemic strokes (one of which was followed by intracerebral hemorrhage), and three sinovenous thromboses. Stroke occurred at a median of 5 months after cancer diagnosis. Ten children with strokes had hematologic malignancies and five had brain tumors. Thirteen patients died poststroke, eight because of withdrawal of care. White blood cell count ≥48,000/mm(3) was found in four children, all with intracerebral hemorrhage. Five of seven children with intracerebral hemorrhage had platelets <50,000/mm(3). Stroke has a prevalence of approximately 1% in children with cancer. Hemorrhagic stroke and ischemic stroke occur with approximately equal frequency; children with leukemia and brain tumors are at greatest risk.Pediatric Neurology 08/2013; DOI:10.1016/j.pediatrneurol.2013.04.009 · 1.50 Impact Factor