Maternal parechovirus A (PeV-A) shedding, serostatus, and the risk of central nervous system PeV-A infections in infants.

BACKGROUND: Parechovirus A (PeV-A) has emerged as a leading cause of infant central nervous system (CNS) infections. Risk factors associated with infant acquisition of PeV-A are not well understood. METHODS: We conducted prospective PeV-A/enterovirus (EV) CNS infection surveillance, enrolling 461 hospitalized infants <90 days old who underwent sepsis evaluations and lumbar puncture during 2011-2012. Infants were grouped by RT-PCR detection of PeV-A, EV, or neither virus (Neg) in CSF. We collected demographic/clinical data and tested specimens from all infants. For 427 mothers, we collected demographic/clinical data and evaluated PeV-A3 and EV shedding, and PeV-A3 neutralizing antibody for 147 mothers. RESULTS: PeV-A was detected in 40 infants (8.7%), 4 in 2011 and 36 in 2012. EV was detected in 35 infants (7.6%), 16 in 2011, and 19 in 2012. PeV-A infected infants presented with irritability, abdominal discomfort, fever, and tachycardia, plus both lymphopenia and absence of CSF pleocytosis which help differentiate PeV-A from EV CNS infection. PeV-A was detected in 9/427 maternal throat swabs; eight of their infants also had PeV-A CNS infection. Infants whose mothers had PeV-A3-positive throat swabs were more likely to be PeV-A3-positive than infants whose mothers had negative throat swabs (relative risk [RR], 13.4 [95% CI, 8.6 - 20.7]). Maternal PeV-A3 seropositivity decreased with increasing maternal age. Mothers of PeV-A-positive infants had lower median PeV-A3 neutralizing titers and were more likely seronegative. CONCLUSIONS: Maternal viral shedding, serostatus and neutralization titers appear to be important factors in infant PeV-A3 CNS infections.

Antibiotic Regimens and Associated Outcomes in Children Hospitalized With Staphylococcal Scalded Skin Syndrome.

BACKGROUND: Controversy exists regarding the optimal antibiotic regimen for use in hospitalized children with staphylococcal scalded skin syndrome (SSSS). Various regimens may confer toxin suppression and/or additional coverage for methicillin-susceptible Staphylococcus aureus (MSSA) or methicillin-resistant S aureus (MRSA). OBJECTIVES: To describe antibiotic regimens in hospitalized children with SSSS and examine the association between antistaphylococcal antibiotic regimens and patient outcomes. DESIGN/METHODS: Retrospective cohort study of children hospitalized with SSSS using the Pediatric Health Information System database (2011-2016). Children who received clindamycin monotherapy, clindamycin plus MSSA coverage (eg, nafcillin), or clindamycin plus MRSA coverage (eg, vancomycin) were included. The primary outcome was hospital length of stay (LOS); secondary outcomes were treatment failure and cost. Generalized linear mixed-effects models were used to compare outcomes among antibiotic groups. RESULTS: Of 1,259 children included, 828 children received the most common antistaphylococcal antibiotic regimens: clindamycin monotherapy (47%), clindamycin plus MSSA coverage (33%), and clindamycin plus MRSA coverage (20%). Children receiving clindamycin plus MRSA coverage had higher illness severity (44%) compared with clindamycin monotherapy (28%) and clindamycin plus MSSA (32%) (P =.001). In adjusted analyses, LOS and treatment failure did not differ among the 3 regimens (P =.42 and P =.26, respectively). Cost was significantly lower for children receiving clindamycin monotherapy and highest in those receiving clindamycin plus MRSA coverage (mean, $4,839 vs $5,348, respectively; P <.001). CONCLUSIONS: In children with SSSS, the addition of MSSA or MRSA coverage to clindamycin monotherapy was associated with increased cost and no incremental difference in clinical outcomes.

Invasive Bacterial Infections in Infants Younger Than 60 Days With Skin and Soft Tissue Infections.

OBJECTIVE: The objective of this study was to describe the frequency of invasive bacterial infections (IBIs) in young infants with skin and soft tissue infections (SSTIs) and the impact of IBI evaluation on disposition, length of stay (LOS), and cost. METHODS: This retrospective (2009-2014) cohort study used data from 35 children's hospitals in the Pediatric Health Information System. We included infants younger than 60 days who presented to an emergency department (ED) with SSTI. Invasive bacterial infection was defined as bacteremia/sepsis, bone/joint infection, or bacterial meningitis. Readmission and return ED visits within 30 days were evaluated to identify missed IBIs for infants. RESULTS: A total of 2734 infants were included (median age, 33 days; interquartile range [IQR], 21-44); 62% were hospitalized. Invasive bacterial infection was identified in 2%: bacteremia (1.8%), osteomyelitis (0.1%), and bacterial meningitis (0.1%). Hospitalization occurred in 78% of infants with blood cultures, 95% with cerebrospinal fluid cultures, and 23% without cultures. Median hospitalization LOS was 2 days (IQR, 1-3). Median cost was US $4943 for infants with cerebrospinal fluid cultures (IQR, US $3475-6780) compared with US $419 (IQR, US $215-1149) for infants without IBI evaluations (P < 0.001). Five infants (0.2%) returned to the ED within 30 days with new IBI diagnoses (4 bacteremia, 1 meningitis). CONCLUSIONS: Invasive bacterial infection occurs infrequently in infants younger than 60 days who present to children's hospital EDs with SSTI. Bacteremia is the most common IBI. More extensive evaluation for IBI is associated with increased rate of admission, LOS, and cost. Further studies are needed to evaluate the safety of a limited IBI evaluation in young infants with SSTI.

Implementation of a General Pediatric Clinical Rounding Checklist.

BACKGROUND: Checklists have been found to improve patient outcomes in a variety of health care settings, but use is rare during general pediatric rounds. We aimed to decrease length of stay (LOS) by 10% within 12 months through the standardized delivery of 8 aspects of hospital care for the general pediatric unit. METHODS: For the general pediatrics unit at our freestanding children's hospital, a clinical rounding checklist was developed through a consensus of teaching faculty. Iterative plan-do-study-act cycles were conducted in a targeted medical unit over a 12-month period. We assessed change using control charts. RESULTS: Checklist use increased from 61% to 96% early in the implementation phase. LOS (72 hours) was relatively unchanged. Cardiorespiratory monitor (CRM) duration was reduced by 28% (17.3 hours) within 4 months and was sustained for more than 12 months. A similar CRM reduction of 29% (22.5 hours) was seen in our medically complex patient subgroup. No clinically significant change was appreciated in central line, peripheral intravenous (IV) catheter, IV fluid, or IV medication duration. Thirty-day readmissions, code blue events, and rapid response team activations were not impacted. CONCLUSIONS: The use of a clinical rounding checklist on the general pediatric floor improved care in only 1 of 8 targeted domains. LOS did not change significantly over the project's duration. CRM duration was significantly reduced in both routine patients and medically complex children, and these improvements were sustained without impacting patient safety. More study is needed to determine which checklist components, if any, may prove beneficial to patient outcomes.

Urban-Rural Residence and Child Physical Abuse Hospitalizations: A National Incidence Study.

OBJECTIVE: To determine if child physical abuse hospitalization rates vary across urban-rural regions overall and after accounting for race/ethnicity and poverty demographics. STUDY DESIGN: This was a retrospective cross-sectional study of black, Hispanic, and non-Hispanic white children <5 years of age living in all US counties. US counties were classified as central metro, fringe/small metro, and rural. Incidence rates were calculated using child physical abuse hospitalization counts from the 2012 Kids' Inpatient Database and population statistics from the 2012 American Community Survey. Counties' race/ethnicity demographics and percent of children living in poverty were used to adjust rates. RESULTS: We identified 3082 child physical abuse hospitalizations occurring among 18.2 million children. Neither crude nor adjusted overall rates of child physical abuse hospitalizations varied significantly across the urban-rural spectrum. When stratified by race/ethnicity, crude child physical abuse hospitalization rates decreased among black children 29.1% (P = .004) and increased among white children 25.6% (P = .001) from central metro to rural counties. After adjusting for poverty, only rates among black children continued to vary significantly, decreasing 34.8% (P = .001) from central metro to rural counties. Rates were disproportionately higher among black children compared with white children and their disproportionality increased with population density, even after poverty adjustment. Rates among Hispanic children were disproportionately lower compared with white children in nearly all urban-rural categories. CONCLUSIONS: Our results suggest that urban black children have unique exposures, outside of poverty, increasing their risk for child physical abuse hospitalization. Identifying and addressing these unique urban exposures may aid in reducing black-white disproportionalities in child physical abuse.

Variation in Antibiotic Selection and Clinical Outcomes in Infants <60 Days Hospitalized With Skin and Soft Tissue Infections.

OBJECTIVES: To describe variation in empirical antibiotic selection in infants <60 days old who are hospitalized with skin and soft-tissue infections (SSTIs) and to determine associations with outcomes, including length of stay (LOS), 30-day returns (emergency department revisit or readmission), and standardized cost. METHODS: Using the Pediatric Health Information System, we conducted a retrospective study of infants hospitalized with SSTI from 2009 to 2014. We analyzed empirical antibiotic selection in the first 2 days of hospitalization and categorized antibiotics as those typically administered for (1) staphylococcal infection, (2) neonatal sepsis, or (3) combination therapy (staphylococcal infection and neonatal sepsis). We examined the association of antibiotic selection and outcomes using generalized linear mixed-effects models. RESULTS: A total of 1319 infants across 36 hospitals were included; the median age was 30 days (interquartile range [IQR]: 17-42 days). We observed substantial variation in empirical antibiotic choice, with 134 unique combinations observed before categorization. The most frequently used antibiotics included staphylococcal therapy (50.0% [IQR: 39.2-58.1]) and combination therapy (45.4% [IQR: 36.0-56.0]). Returns occurred in 9.2% of infants. Compared with administration of staphylococcal antibiotics, use of combination therapy was associated with increased LOS (adjusted rate ratio: 1.35; 95% confidence interval: 1.17-1.53) and cost (adjusted rate ratio: 1.39; 95% confidence interval: 1.21-1.58), but not with 30-day returns. CONCLUSIONS: Infants who are hospitalized with SSTI experience wide variation in empirical antibiotic selection. Combination therapy was associated with increased LOS and cost, with no difference in returns. Our findings reveal the need to identify treatment strategies that can be used to optimize resource use for infants with SSTI.

Sexually Transmitted Infection Testing in Adolescents: Current Practices in the Hospital Setting.

PURPOSE: Adolescents are disproportionately affected by sexually transmitted infections (STIs), and evidence supports expanding sexual health services to the hospital setting. Because STI testing practices in the hospital setting are poorly understood, we sought to describe current STI testing practices among adolescents seen in children's hospitals. METHODS: We performed a retrospective analysis of adolescents (14-18 years old) from 45 children's hospitals in 2015-2016, excluding visits with a billing code for sexual abuse/assault. We calculated rates of STI testing and investigated differences in STI testing by patient and hospital characteristics using generalized linear mixed modeling. RESULTS: Of the 541,714 adolescent encounters, 59,158 (10.9%) underwent STI testing. After adjusting for demographic characteristics, those with an STI test were more likely to be female (adjusted odds ratio [aOR] 1.61; 95% confidence interval [CI] 1.58-1.64), of non-Hispanic black race/ethnicity (aOR 1.20; 95% CI 1.17-1.23), or from the lowest median household income quartile (aOR 1.21; 95% CI 1.17-1.24). There was substantial inter-hospital variation in adjusted rates of STI testing (3%-24%), but strong correlation was observed between STI testing rates in the ED and inpatient settings within individual hospitals (adjusted R2 .99). CONCLUSIONS: Only one in ten adolescents seen in children's hospitals underwent STI testing with wide variation in testing patterns across hospitals. There are critical opportunities to increase adolescent STI testing in this setting. Our findings highlight potential disparities in STI testing rates and patterns that warrant further exploration from the patient, provider, and health system perspective.

Variation in Diagnostic Test Use and Associated Outcomes in Staphylococcal Scalded Skin Syndrome at Children's Hospitals.

OBJECTIVES: The incidence of staphylococcal scalded skin syndrome (SSSS) is rising, but current practice variation in diagnostic test use is not well described. Our aim was to describe the variation in diagnostic test use in children hospitalized with SSSS and to determine associations with patient outcomes. METHODS: We performed a retrospective (2011-2016) cohort study of children aged 0 to 18 years from 35 children's hospitals in the Pediatric Health Information System database. Tests included blood culture, complete blood count, erythrocyte sedimentation rate, C-reactive protein level, serum chemistries, and group A streptococcal testing. K-means clustering was used to stratify hospitals into groups of high (cluster 1) and low (cluster 2) test use. Associations between clusters and patient outcomes (length of stay, cost, readmissions, and emergency department revisits) were assessed with generalized linear mixed-effects modeling. RESULTS: We included 1259 hospitalized children with SSSS; 84% were ≤4 years old. Substantial interhospital variation was seen in diagnostic testing. Blood culture was the most commonly obtained test (range 62%-100%), with the most variation seen in inflammatory markers (14%-100%). Between hospital clusters 1 and 2, respectively, there was no significant difference in adjusted length of stay (2.6 vs 2.5 days; P = .235), cost ($4752 vs $4453; P = .591), same-cause 7-day readmission rate (0.8% vs 0.4%; P = .349), or emergency department revisit rates (0.1% vs 0.6%; P = .148). CONCLUSIONS: For children hospitalized with SSSS, lower use of diagnostic tests was not associated with changes in outcomes. Hospitals with high diagnostic test use may be able to reduce testing without adversely affecting patient outcomes.

Association of Income Inequality With Pediatric Hospitalizations for Ambulatory Care-Sensitive Conditions.

Importance: The level of income inequality (ie, the variation in median household income among households within a geographic area), in addition to family-level income, is associated with worsened health outcomes in children. Objective: To determine the influence of income inequality on pediatric hospitalization rates for ambulatory care-sensitive conditions (ACSCs) and whether income inequality affects use of resources per hospitalization for ACSCs. Design, Setting, and Participants: This retrospective, cross-sectional analysis used the 2014 State Inpatient Databases of the Healthcare Cost and Utilization Project of 14 states to evaluate all hospital discharges for patients aged 0 to 17 years (hereafter referred to as children) from January 1 through December 31, 2014. Exposures: Using the 2014 American Community Survey (US Census), income inequality (Gini index; range, 0 [perfect equality] to 1.00 [perfect inequality]), median household income, and total population of children aged 0 to 17 years for each zip code in the 14 states were measured. The Gini index for zip codes was divided into quartiles for low, low-middle, high-middle, and high income inequality. Main Outcomes and Measures: Rate, length of stay, and charges for pediatric hospitalizations for ACSCs. Results: A total of 79 275 hospitalizations for ACSCs occurred among the 21 737 661 children living in the 8375 zip codes in the 14 included states. After adjustment for median household income and state of residence, ACSC hospitalization rates per 10 000 children increased significantly as income inequality increased from low (27.2; 95% CI, 26.5-27.9) to low-middle (27.9; 95% CI, 27.4-28.5), high-middle (29.2; 95% CI, 28.6-29.7), and high (31.8; 95% CI, 31.2-32.3) categories (P < .001). A significant, clinically unimportant longer length of stay was found for high inequality (2.5 days; 95% CI, 2.4-2.5 days) compared with low inequality (2.4 days; 95% CI, 2.4-2.5 days; P < .001) zip codes and between charges ($765 difference among groups; P < .001). Conclusions and Relevance: Children living in areas of high income inequality have higher rates of hospitalizations for ACSCs. Consideration of income inequality, in addition to income level, may provide a better understanding of the complex relationship between socioeconomic status and pediatric health outcomes for ACSCs. Efforts aimed at reducing rates of hospitalizations for ACSCs should consider focusing on areas with high income inequality.

Clinical Course of Enterovirus D68 in Hospitalized Children.

BACKGROUND: Enterovirus D68 (EV-D68) has been sporadically reported as a cause of respiratory tract infections. In 2014, an international outbreak of EV-D68 occurred and caused severe respiratory disease in the pediatric population. METHODS: A retrospective chart review was performed of children admitted to Children's Mercy Hospital from August 1, 2014, to September 15, 2014, with positive multiplex polymerase chain reaction testing for EV/rhinovirus (RV). Specimens were subsequently tested for EV-D68, and clinical data were obtained from the medical records. Patients with EV-D68 were compared with children presenting simultaneously with other EV/RV. RESULTS: Of 542 eligible specimens, children with EV-D68 were significantly older than children with other EV/RV (4.6 vs. 2.2 years, P < 0.001). Children with EV-D68 were more likely to have a history of asthma (38.6% vs. 30.0%, P = 0.04) or recurrent wheezing (22.1% vs. 14.8%, P = 0.04). EV-D68-positive children more commonly received supplemental oxygen (86.7% vs. 65.0%, P < 0.001), albuterol (91.2% vs. 65.5%, P < 0.001) and corticosteroids (82.9% vs. 58.6%, P < 0.001). Age ≥5 years was an independent risk factor for intensive care unit management in EV-D68-infected children. Children with a history of asthma or recurrent wheezing and EV-D68 received supplemental oxygen (92.7% vs. 82.4%, P = 0.007) and magnesium (42.7% vs. 29.7%, P = 0.03) at higher rates and more continuous albuterol (3 vs. 2 hours, P = 0.03) than those with other EV/RV. CONCLUSIONS: EV-D68 causes severe disease in the pediatric population, particularly in children with a history of asthma or recurrent wheezing. EV-D68-positive children are more likely to require therapy for refractory bronchospasm and may need intensive care unit- level care.

Clinical Impact of an Antimicrobial Stewardship Program on Pediatric Hospitalist Practice, a 5-Year Retrospective Analysis.

BACKGROUND AND OBJECTIVES: Hospitalists increasingly serve as the primary physicians for children hospitalized with infections. Consequently, hospitalists frequently interact with institutional antimicrobial stewardship programs (ASPs). Understanding how these services interact can inform ongoing practice improvement efforts. The objectives of this study were to identify factors associated with ASP recommendations among hospitalist-managed children, and to determine the association of ASP interventions with clinical outcomes for hospitalist-managed patients. METHODS: We retrospectively analyzed ASP reviews of hospitalist patients from a children's hospital from March 2008 to June 2013. Clinical factors associated with an ASP recommendation were determined. Length of stay and 30-day readmission were compared between cases of agreement and disagreement with ASP recommendations. RESULTS: The ASP reviewed 2163 hospitalist patients, resulting in 350 recommendations (16.2% of reviews). Hospitalists agreed with ASP recommendations in 86.9% of cases. The odds of an ASP recommendation decreased during the study period. Ceftriaxone was the most common antibiotic associated with a recommendation (154/350, 44.0%); community-acquired pneumonia was the most common diagnosis (105/350, 30.0%). Antibiotic discontinuation was the most often recommendation; hospitalists most often disagreed with consulting infectious diseases. Disagreement with ASP recommendations was associated with a decreased length of stay of 15.4 (95% confidence interval -33.2 to 1.1) hours but not 30-day readmission prevalence. CONCLUSIONS: Pediatric hospitalists and ASPs can form an effective collaboration that improves antibiotic use while providing safe care. Better characterization of the areas of disagreement between hospitalists and ASPs is needed. Future studies are needed to identify ASP strategies that will be beneficial in other hospitalist settings.

Association of White Blood Cell Count and C-Reactive Protein with Outcomes in Children Hospitalized for Community-acquired Pneumonia.

We examined the association between baseline peripheral white blood cell count and C-reactive protein (CRP) values with outcomes among 153 children hospitalized with pneumonia. In multivariable analyses, CRP, but not white blood cell count, was significantly associated with both fever duration and hospital length of stay. For every 1mg/dL increase in CRP, length of stay increased by 1 hour.

Childhood obesity and in-hospital asthma resource utilization.

OBJECTIVE: To examine the relationship between pediatric obesity and inpatient length of stay (LOS), resource utilization, readmission rates, and total billed charges for in-hospital status asthmaticus. DESIGN/METHODS: We conducted a cross-sectional study of patients 5 to 17 years old hospitalized with status asthmaticus to 1 free-standing children's hospital system over 12 months. Only hospitalized patients initially treated in the hospital's emergency department were included to ensure all therapies/charges were examined. Patients with complex chronic conditions, pneumonia, or lacking recorded body mass index (BMI) were excluded. The primary exposure was BMI percentile for age. The primary outcome was LOS (in hours). Secondary outcomes were 90-day readmission rate, billed charges, and resource utilization: number of albuterol treatments, chest radiographs, intravenous fluids, intravenous or intramuscular steroids, and intensive care unit admission. Bivariate, adjusted Poisson and logistic regression model analyses were performed. RESULTS: Five hundred eighteen patients met inclusion criteria. Most had a normal BMI (59.7%); 36.7% were overweight or obese. LOS, readmissions, and resource utilization outcomes were not associated with BMI category on bivariate analyses. After adjustment for demographic/clinical characteristics, LOS decreased by 2% for each decile increase in BMI percentile for age. BMI percentile for age was not associated with billed charges, readmissions, or other measures of resource utilization. CONCLUSIONS: Although BMI decile for age is inversely associated with LOS for in-hospital pediatric status asthmaticus, the effect likely is not clinically meaningful.

Admission chest radiographs predict illness severity for children hospitalized with pneumonia.

OBJECTIVE: To assess whether radiographic findings predict outcomes among children hospitalized with pneumonia. METHODS: This retrospective study included children <18 years of age from 4 children's hospitals admitted in 2010 with clinical and radiographic evidence of pneumonia. Admission radiographs were categorized as single lobar, unilateral or bilateral multilobar, or interstitial. Pleural effusions were classified as absent, small, or moderate/large. Propensity scoring was used to adjust for potential confounders, including need for supplemental oxygen, intensive care, and mechanical ventilation, as well as hospital length of stay and duration of supplemental oxygen. RESULTS: There were 406 children (median age, 3 years). Infiltrate patterns included: single lobar, 61%; multilobar unilateral, 13%; multilobar bilateral, 16%; and interstitial, 10%. Pleural effusion was present in 21%. Overall, 63% required supplemental oxygen (median duration, 31.5 hours), 8% required intensive care, and 3% required mechanical ventilation. Median length of stay was 51.5 hours. Compared with single lobar infiltrate, all other infiltrate patterns were associated with need for intensive care; only bilateral multilobar infiltrate was associated with need for mechanical ventilation (adjusted odds ratio [aOR]: 3.0, 95% confidence interval [CI]: 1.2-7.9). Presence of effusion was associated with increased length of stay and duration of supplemental oxygen; only moderate/large effusion was associated with need for intensive care (aOR: 3.2, 95% CI: 1.1-8.9) and mechanical ventilation (aOR: 14.8, 95% CI: 9.8-22.4). CONCLUSIONS: Admission radiographic findings are associated with important hospital outcomes and care processes and may help predict disease severity.

Comparative effectiveness of empiric antibiotics for community-acquired pneumonia.

BACKGROUND AND OBJECTIVE: Narrow-spectrum antibiotics are recommended as the first-line agent for children hospitalized with community-acquired pneumonia (CAP). There is little scientific evidence to support that this consensus-based recommendation is as effective as the more commonly used broad-spectrum antibiotics. The objective was to compare the effectiveness of empiric treatment with narrow-spectrum therapy versus broad-spectrum therapy for children hospitalized with uncomplicated CAP. METHODS: This multicenter retrospective cohort study using medical records included children aged 2 months to 18 years at 4 children's hospitals in 2010 with a discharge diagnosis of CAP. Patients receiving either narrow-spectrum or broad-spectrum therapy in the first 2 days of hospitalization were eligible. Patients were matched by using propensity scores that determined each patient's likelihood of receiving empiric narrow or broad coverage. A multivariate logistic regression analysis evaluated the relationship between antibiotic and hospital length of stay (LOS), 7-day readmission, standardized daily costs, duration of fever, and duration of supplemental oxygen. RESULTS: Among 492 patients, 52% were empirically treated with a narrow-spectrum agent and 48% with a broad-spectrum agent. In the adjusted analysis, the narrow-spectrum group had a 10-hour shorter LOS (P = .04). There was no significant difference in duration of oxygen, duration of fever, or readmission. When modeled for LOS, there was no difference in average daily standardized cost (P = .62) or average daily standardized pharmacy cost (P = .26). CONCLUSIONS: Compared with broad-spectrum agents, narrow-spectrum antibiotic coverage is associated with similar outcomes. Our findings support national consensus recommendations for the use of narrow-spectrum antibiotics in children hospitalized with CAP.

Identifying pediatric community-acquired pneumonia hospitalizations: Accuracy of administrative billing codes.

IMPORTANCE: Community-acquired pneumonia (CAP) remains one of the most common indications for pediatric hospitalization in the United States, and it is frequently the focus of research and quality studies. Use of administrative data is increasingly common for these purposes, although proper validation is required to ensure valid study conclusions. OBJECTIVE: To validate administrative billing data for hospitalizations owing to childhood CAP. DESIGN AND SETTING: Case-control study of 4 tertiary care, freestanding children's hospitals in the United States. PARTICIPANTS: A total of 998 medical records of a 25% random sample of 3646 children discharged in 2010 with at least 1 International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) code representing possible pneumonia were reviewed. Discharges (matched on date of admission) without a pneumonia-related discharge code were also examined to identify potential missed pneumonia cases. Two reference standards, based on provider diagnosis alone (provider confirmed) or in combination with consistent clinical and radiographic evidence of pneumonia (definite), were used to identify CAP. EXPOSURE: Twelve ICD-9-CM­based coding strategies, each using a combination of primary or secondary codes representing pneumonia or pneumonia-related complications. Six algorithms excluded children with complex chronic conditions. MAIN OUTCOMES AND MEASURES: Sensitivity, specificity, and negative and positive predictive values (NPV and PPV, respectively) of the 12 identification strategies. RESULTS: For provider-confirmed CAP (n = 680), sensitivity ranged from 60.7% to 99.7%; specificity, 75.7% to 96.4%; PPV, 67.9% to 89.6%; and NPV, 82.6% to 99.8%. For definite CAP (n = 547), sensitivity ranged from 65.6% to 99.6%; specificity, 68.7% to 93.0%; PPV, 54.6% to 77.9%; and NPV, 87.8% to 99.8%. Unrestricted use of the pneumonia-related codes was inaccurate, although several strategies improved specificity to more than 90% with a variable effect on sensitivity. Excluding children with complex chronic conditions demonstrated the most favorable performance characteristics. Performance of the algorithms was similar across institutions. CONCLUSIONS AND RELEVANCE: Administrative data are valuable for studying pediatric CAP hospitalizations. The strategies presented here will aid in the accurate identification of relevant and comparable patient populations for research and performance improvement studies.