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Tamara D. Simon

University of Southern California

ORCID: 0000-0003-4734-7020

Publishes on Cerebrospinal fluid and hydrocephalus, Spinal Dysraphism and Malformations, Head and Neck Surgical Oncology. 97 papers and 5.1k citations.

97Publications
5.1kTotal Citations

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Children With Complex Chronic Conditions in Inpatient Hospital Settings in the United States
Cited by 721Open Access

OBJECTIVES: Hospitalized children are perceived to be increasingly medically complex, but no such trend has been documented. The objective of this study was to determine whether the proportion of pediatric inpatient use that is attributable to patients with a diagnosis of one or more complex chronic condition (CCC) has increased over time and to assess the degree to which CCC hospitalizations are associated with attributes that are consistent with heightened medical complexity. METHODS: A retrospective observational study that used the 1997, 2000, 2003, and 2006 Kids Inpatient Databases examined US hospitalizations for children. Attributes of medical complexity included hospital admissions, length of stay, total charges, technology-assistance procedures, and mortality risk. RESULTS: The proportion of inpatient pediatric admissions, days, and charges increased from 1997 to 2006 for any CCC and for every CCC group except hematology. CCCs accounted for 8.9% of US pediatric admissions in 1997 and 10.1% of admissions in 2006. These admissions used 22.7% to 26.1% of pediatric hospital days, used 37.1% to 40.6% of pediatric hospital charges, accounted for 41.9% to 43.2% of deaths, and (for 2006) used 73% to 92% of different forms of technology-assistance procedures. As the number of CCCs for a given admission increased, all markers of use increased. CONCLUSIONS: CCC-associated hospitalizations compose an increasing proportion of inpatient care and resource use. Future research should seek to improve methods to identify the population of medically complex children, monitor their increasing inpatient use, and assess whether current systems of care are meeting their needs.

Pediatric Medical Complexity Algorithm: A New Method to Stratify Children by Medical Complexity
Cited by 454

OBJECTIVES: The goal of this study was to develop an algorithm based on International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), codes for classifying children with chronic disease (CD) according to level of medical complexity and to assess the algorithm's sensitivity and specificity. METHODS: A retrospective observational study was conducted among 700 children insured by Washington State Medicaid with ≥1 Seattle Children's Hospital emergency department and/or inpatient encounter in 2010. The gold standard population included 350 children with complex chronic disease (C-CD), 100 with noncomplex chronic disease (NC-CD), and 250 without CD. An existing ICD-9-CM-based algorithm called the Chronic Disability Payment System was modified to develop a new algorithm called the Pediatric Medical Complexity Algorithm (PMCA). The sensitivity and specificity of PMCA were assessed. RESULTS: Using hospital discharge data, PMCA's sensitivity for correctly classifying children was 84% for C-CD, 41% for NC-CD, and 96% for those without CD. Using Medicaid claims data, PMCA's sensitivity was 89% for C-CD, 45% for NC-CD, and 80% for those without CD. Specificity was 90% to 92% in hospital discharge data and 85% to 91% in Medicaid claims data for all 3 groups. CONCLUSIONS: PMCA identified children with C-CD (who have accessed tertiary hospital care) with good sensitivity and good to excellent specificity when applied to hospital discharge or Medicaid claims data. PMCA may be useful for targeting resources such as care coordination to children with C-CD.

Hospital care for children with hydrocephalus in the United States: utilization, charges, comorbidities, and deaths
Tamara D. Simon, Jay Riva-Cambrin, Rajendu Srivastava et al.|Journal of Neurosurgery Pediatrics|2008
Cited by 383

OBJECT: The aims of this study were to measure inpatient health care for pediatric hydrocephalus in the US; describe patient, hospital, and hospitalization characteristics for pediatric hydrocephalus inpatient care; and determine characteristics associated with death. METHODS: A cross-sectional study was performed using the 1997, 2000, and 2003 Healthcare Cost and Utilization Project Kids' Inpatient Databases (KID), nationally representative weighted data sets of hospital discharges for pediatric patients. A hydrocephalus-related hospitalization was classified as either cerebrospinal fluid (CSF) shunt-related (including initial placements, infections, malfunctions, or other) or non-CSF shunt-related. Patients>18 years of age were excluded. The KID provided weighted estimates of 6.657, 6.597, and 6.732 million total discharges in the 3 study years. RESULTS: Each year there were 38,200-39,900 admissions, 391,000-433,000 hospital days, and total hospital charges of $1.4-2.0 billion for pediatric hydrocephalus. Hydrocephalus accounted for 0.6% of all pediatric hospital admissions in the US in 2003, but for 1.8% of all pediatric hospital days and 3.1% of all pediatric hospital charges. Over the study years, children admitted with hydrocephalus were older, had an increase in comorbidities, and were admitted more frequently to teaching hospitals. Compared with children who survived, those who died were more likely to be <3 months of age and have a birth-related admission, have no insurance, have comorbidities, be transferred, and have a non-CSF shunt-related admission. CONCLUSIONS: Children with hydrocephalus have a chronic illness and use a disproportionate share of hospital days and healthcare dollars in the US. Since 1997 they have increased in age and in number of comorbid conditions. For important changes in morbidity and mortality rates to be made, focused research efforts and funding are necessary.

A standardized protocol to reduce cerebrospinal fluid shunt infection: The Hydrocephalus Clinical Research Network Quality Improvement Initiative
John R. W. Kestle, Jay Riva-Cambrin, John C. Wellons et al.|Journal of Neurosurgery Pediatrics|2011
Cited by 305

OBJECT: Quality improvement techniques are being implemented in many areas of medicine. In an effort to reduce the ventriculoperitoneal shunt infection rate, a standardized protocol was developed and implemented at 4 centers of the Hydrocephalus Clinical Research Network (HCRN). METHODS: The protocol was developed sequentially by HCRN members using the current literature and prior institutional experience until consensus was obtained. The protocol was prospectively applied at each HCRN center to all children undergoing a shunt insertion or revision procedure. Infections were defined on the basis of CSF, wound, or pseudocyst cultures; wound breakdown; abdominal pseudocyst; or positive blood cultures in the presence of a ventriculoatrial shunt. Procedures and infections were measured before and after protocol implementation. RESULTS: Twenty-one surgeons at 4 centers performed 1571 procedures between June 1, 2007, and February 28, 2009. The minimum follow-up was 6 months. The Network infection rate decreased from 8.8% prior to the protocol to 5.7% while using the protocol (p = 0.0028, absolute risk reduction 3.15%, relative risk reduction 36%). Three of 4 centers lowered their infection rate. Shunt surgery after external ventricular drainage (with or without prior infection) had the highest infection rate. Overall protocol compliance was 74.5% and improved over the course of the observation period. Based on logistic regression analysis, the use of BioGlide catheters (odds ratio [OR] 1.91, 95% CI 1.19-3.05; p = 0.007) and the use of antiseptic cream by any members of the surgical team (instead of a formal surgical scrub by all members of the surgical team; OR 4.53, 95% CI 1.43-14.41; p = 0.01) were associated with an increased risk of infection. CONCLUSIONS: The standardized protocol for shunt surgery significantly reduced shunt infection across the HCRN. Overall protocol compliance was good. The protocol has established a common baseline within the Network, which will facilitate assessment of new treatments. Identification of factors associated with infection will allow further protocol refinement in the future.

Risk factors for shunt malfunction in pediatric hydrocephalus: a multicenter prospective cohort study
Jay Riva-Cambrin, John R. W. Kestle, Richard Holubkov et al.|Journal of Neurosurgery Pediatrics|2015
Cited by 274

OBJECT The rate of CSF shunt failure remains unacceptably high. The Hydrocephalus Clinical Research Network (HCRN) conducted a comprehensive prospective observational study of hydrocephalus management, the aim of which was to isolate specific risk factors for shunt failure. METHODS The study followed all first-time shunt insertions in children younger than 19 years at 6 HCRN centers. The HCRN Investigator Committee selected, a priori, 21 variables to be examined, including clinical, radiographic, and shunt design variables. Shunt failure was defined as shunt revision, subsequent endoscopic third ventriculostomy, or shunt infection. Important a priori-defined risk factors as well as those significant in univariate analyses were then tested for independence using multivariate Cox proportional hazard modeling. RESULTS A total of 1036 children underwent initial CSF shunt placement between April 2008 and December 2011. Of these, 344 patients experienced shunt failure, including 265 malfunctions and 79 infections. The mean and median length of follow-up for the entire cohort was 400 days and 264 days, respectively. The Cox model found that age younger than 6 months at first shunt placement (HR 1.6 [95% CI 1.1-2.1]), a cardiac comorbidity (HR 1.4 [95% CI 1.0-2.1]), and endoscopic placement (HR 1.9 [95% CI 1.2-2.9]) were independently associated with reduced shunt survival. The following had no independent associations with shunt survival: etiology, payer, center, valve design, valve programmability, the use of ultrasound or stereotactic guidance, and surgeon experience and volume. CONCLUSIONS This is the largest prospective study reported on children with CSF shunts for hydrocephalus. It confirms that a young age and the use of the endoscope are risk factors for first shunt failure and that valve type has no impact. A new risk factor-an existing cardiac comorbidity-was also associated with shunt failure.