Structure and Function of Observation Units in Children's Hospitals: A Mixed-Methods Study.

OBJECTIVE: Observation unit (OU) use has been promoted recently to decrease resource utilization and costs for select patients, but little is known about the operations of pediatric OUs. This study aimed to characterize the infrastructure and function of OUs within freestanding children's hospitals and to compare characteristics between hospitals with and without OUs. METHODS: All 43 freestanding children's hospitals that submit data to the Pediatric Health Information System were contacted in 2013 to identify OUs that admitted unscheduled patients from their emergency department (ED) in 2011. Semistructured interviews were conducted with representatives at hospitals with these OUs. Characteristics of hospitals with and without OUs were compared. RESULTS: Fourteen (33%) of 43 hospitals had an OU during 2011. Hospitals with OUs had more beds and more annual ED visits compared to those without OUs. Most OUs (65%) were located in the ED and had <12 beds (65%). Staffing models and patient populations differed between OUs. Nearly 60% were hybrid OUs, providing scheduled services. OUs lacked uniform outcome measures. Themes included: admissions were intuition based, certain patients were not well suited for OUs, OUs had rapid-turnover cultures, and the designation of observation status was arbitrary. Challenges included patient discontent with copayments and payer-driven utilization reviews. CONCLUSIONS: OUs were located in higher volume hospitals and varied by location, size, and staffing. Most functioned as hybrid OUs. OUs based admissions on intuition, had staffing cultures centered on rapid turnover of patient care, lacked consistent outcome measures, and faced challenges regarding utilization review and patient copayments.

Observation-status patients in children's hospitals with and without dedicated observation units in 2011.

BACKGROUND: Pediatric observation units (OUs) have demonstrated reductions in lengths of stay (LOS) and costs of care. Hospital-level outcomes across all observation-status stays have not been evaluated in relation to the presence of a dedicated OU in the hospital. OBJECTIVE: To compare observation-status stay outcomes in hospitals with and without a dedicated OU. DESIGN: Cross-sectional analysis of hospital administrative data. METHODS: Observation-status stay outcomes were compared in hospitals with and without a dedicated OU across 4 categories: (1) LOS, (2) standardized costs, (3) conversion to inpatient status, and (4) return care. SETTING/PATIENTS: Observation-status stays in 31 free-standing children's hospitals contributing observation patient data to the Pediatric Health Information System database, 2011. RESULTS: Fifty-one percent of the 136,239 observation-status stays in 2011 occurred in 14 hospitals with a dedicated OU; the remainder were in 17 hospitals without. The percentage of observation-status same-day discharges was higher in hospitals with a dedicated OU compared with hospitals without (23.8 vs 22.1, P < 0.001), but risk-adjusted LOS in hours and total standardized costs were similar. Conversion to inpatient status was higher in hospitals with a dedicated OU (11.06%) compared with hospitals without (9.63%, P < 0.01). Adjusted odds of return visits and readmissions were comparable. CONCLUSIONS: The presence of a dedicated OU appears to have an influence on same-day and morning discharges across all observation-status stays without impacting other hospital-level outcomes. Inclusion of location of care (eg, dedicated OU, inpatient unit, emergency department) in hospital administrative datasets would allow for more meaningful comparisons of models of hospital care.

Rates and impact of potentially preventable readmissions at children's hospitals.

OBJECTIVE: To assess readmission rates identified by 3M-Potentially Preventable Readmissions software (3M-PPRs) in a national cohort of children's hospitals. STUDY DESIGN: A total of 1 719 617 hospitalizations for 1 531 828 unique patients in 58 children's hospitals from 2009 to 2011 from the Children's Hospital Association Case-Mix Comparative database were examined. Main outcome measures included rates, diagnoses, and costs of potentially preventable readmissions (PPRs) and all-cause readmissions. RESULTS: The 7-, 15-, and 30-day rates by 3M-PPRs were 2.5%, 4.1%, and 6.2%, respectively. Corresponding all-cause readmission rates were 5.0%, 8.7%, and 13.3%. At 30 days, 60.6% of all-cause readmissions were considered nonpreventable by 3M-PPRs, more than one-half of which were related to malignancies. The percentage of readmissions rated as potentially preventable was similar at all 3 time intervals. Readmissions after chemotherapy, acute leukemia, and cystic fibrosis were all considered nonpreventable, and at least 80% of readmissions after index admissions for sickle cell crisis, bronchiolitis, ventricular shunt procedures, asthma, and appendectomy were designated potentially preventable. Total costs for all readmissions were $1.7 billion; PPRs accounted for 27.3% of these costs. The most costly readmissions were associated with ventricular shunt procedures ($26.5 million/year), seizures ($15.5 million/year), and sickle cell crisis ($15.0 million/year). CONCLUSIONS: Rates of PPRs were significantly lower than all-cause readmission rates more than one-half of which were caused by exclusion of malignancies. Annual costs of PPRs, although significant in the aggregate, appear to represent a much smaller cost-savings opportunity for children than for adults. Our study may help guide children's hospitals to focus readmission reduction strategies on areas where the financial vulnerability is greatest based on 3M-PPRs.

Utilization of viral molecular diagnostics among children hospitalized with community acquired pneumonia.

OBJECTIVE: To examine whether results of a polymerase chain reaction-based respiratory viral panel (RVP) are associated with changes in antibiotic use or differential clinical outcomes among children hospitalized with pneumonia. METHODS: We retrospectively identified otherwise healthy children hospitalized over a 3-year period at a single institution with community-acquired pneumonia who had an RVP performed within 24 hours of admission. We examined associations between RVP results and clinical outcomes as well as management decisions including initiation and duration of intravenous antibiotics. RESULTS: Among 202 children, a positive RVP (n = 127, 63%) was associated with a more complicated clinical course, although this was due largely to more severe disease seen in younger children and those with respiratory syncytial virus (n = 38, 30% of positive detections). Detection of a virus did not influence antibiotic therapy. Included children were younger and had more severe illness than children hospitalized with pneumonia at the same institution without an RVP obtained. CONCLUSIONS: In our study, only respiratory syncytial virus was associated with a more severe clinical course compared with RVP-negative children. Regardless of the virus detected, RVP positivity did not influence antibiotic usage. However, RVP use focused primarily on children with severe pneumonia. Whether similar testing influences management decisions among children with less severe illness deserves further study.

Community household income and resource utilization for common inpatient pediatric conditions.

BACKGROUND AND OBJECTIVE: Child health is influenced by biomedical and socioeconomic factors. Few studies have explored the relationship between community-level income and inpatient resource utilization for children. Our objective was to analyze inpatient costs for children hospitalized with common conditions in relation to zip code-based median annual household income (HHI). METHODS: Retrospective national cohort from 32 freestanding children's hospitals for asthma, diabetes, bronchiolitis and respiratory syncytial virus, pneumonia, and kidney and urinary tract infections. Standardized cost of care for individual hospitalizations and across hospitalizations for the same patient and condition were modeled by using mixed-effects methods, adjusting for severity of illness, age, gender, and race. Main exposure was median annual HHI. Posthoc tests compared adjusted standardized costs for patients from the lowest and highest income groups. RESULTS: From 116,636 hospitalizations, 4 of 5 conditions had differences at the hospitalization and at the patient level, with lowest-income groups having higher costs. The individual hospitalization level cost differences ranged from $187 (4.1%) to $404 (6.4%). Patient-level cost differences ranged from $310 to $1087 or 6.5% to 15% higher for the lowest-income patients. Higher costs were typically not for laboratory, imaging, or pharmacy costs. In total, patients from lowest income zip codes had $8.4 million more in hospitalization-level costs and $13.6 million more in patient-level costs. CONCLUSIONS: Lower community-level HHI is associated with higher inpatient costs of care for 4 of 5 common pediatric conditions. These findings highlight the need to consider socioeconomic status in health care system design, delivery, and reimbursement calculations.

Resource utilization for observation-status stays at children's hospitals.

BACKGROUND AND OBJECTIVE: Observation status, in contrast to inpatient status, is a billing designation for hospital payment. Observation-status stays are presumed to be shorter and less resource-intensive, but utilization for pediatric observation-status stays has not been studied. The goal of this study was to describe resource utilization characteristics for patients in observation and inpatient status in a national cohort of hospitalized children in the Pediatric Health Information System. METHODS: This study was a retrospective cohort from 2010 of observation- and inpatient-status stays of ≤2 days; all children were admitted from the emergency department. Costs were analyzed and described. Comparison between costs adjusting for age, severity, and length of stay were conducted by using random-effect mixed models to account for clustering of patients within hospitals. RESULTS: Observation status was assigned to 67 230 (33.3%) discharges, but its use varied across hospitals (2%-45%). Observation-status stays had total median costs of $2559, including room costs and $678 excluding room costs. Twenty-five diagnoses accounted for 74% of stays in observation status, 4 of which were used for detailed analyses: asthma (n = 6352), viral gastroenteritis (n = 4043), bronchiolitis (n = 3537), and seizure (n = 3289). On average, after risk adjustment, observation-status stays cost $260 less than inpatient-status stays for these select 4 diagnoses. Large overlaps in costs were demonstrated for both types of stay. CONCLUSIONS: Variability in use of observation status with large overlap in costs and potential lower reimbursement compared with inpatient status calls into question the utility of segmenting patients according to billing status and highlights a financial risk for institutions with a high volume of pediatric patients in observation status.

Children's hospitals with shorter lengths of stay do not have higher readmission rates.

OBJECTIVE: To test the hypothesis that children's hospitals with shorter length of stay (LOS) for hospitalized patients have higher all-cause readmission rates. STUDY DESIGN: Longitudinal, retrospective cohort study of the Pediatric Health Information System of 183616 admissions within 43 US children's hospitals for appendectomy, asthma, gastroenteritis, and seizure between July 2009 and June 2011. Admissions were stratified by medical complexity, based on whether patients had a complex chronic health condition, were neurologically impaired, or were assisted with medical technology. Outcome measures include LOS; all-cause readmission rates within 3, 7, 15, and 30 days; and the association between hospital-specific mean LOS and all-cause readmission rates as determined by linear regression. RESULTS: Mean LOS was <3 days for all patients across all conditions, except for appendectomy in complex patients (mean LOS 3.7 days, 95% CI 3.47-4.01). Condition-specific 3-, 7-, 15-, and 30-day all-cause readmission rates for noncomplex patients were all <5%. Condition-specific readmission rates for complex patients ranged from <1% at 3 days for seizures to 16% at 30 days for gastroenteritis. There was no linear association between hospital-specific, condition-specific mean LOS, stratified by medical complexity, and all-cause readmission rates at any time interval within 30 days (all P values ≥.10). CONCLUSION: In children's hospitals, LOS is short and readmission rates are low for asthma, appendectomy, gastroenteritis, and seizure admissions. In the conditions studied, there is no association between shorter hospital-specific LOS and higher readmission rates within the LOS observed.

Role of a respiratory viral panel in the clinical management of pediatric inpatients.

BACKGROUND: Respiratory viral panels (RVPs) able to detect multiple pathogens are increasingly used in the management of pediatric inpatients. Despite this, few studies have examined whether the results of these tests are associated with clinically significant changes in medical management. METHODS: In this retrospective cohort study, we identified pediatric inpatients between August 2009 and December 2010 for whom an RVP was ordered within 24 hours of admission to a large, tertiary-care children's hospital. We used linear regression to determine whether RVP was associated with length of stay (LOS), duration of antibiotics and the number of diagnostic microbiology tests ordered, adjusting for potential confounders. RESULTS: We found that the association between results of the RVP and LOS was dependent on a patient's admission service, specifically admission to the hematology/oncology service. We also found that patients with a positive RVP had a shorter duration of intravenous antibiotic administration (P = 0.03; 42% reduction in the geometric mean), but that this was influenced by the primary admission service. We also found that positive results of the RVP were associated with decreased LOS and shorter duration of antibiotics in patients with some common respiratory diagnoses. CONCLUSIONS: This study lacked sufficient evidence to claim an association between a positive RVP and LOS in pediatric patients, adjusting for their underlying diagnosis. However, we found that a positive RVP was associated with a shorter duration of intravenous antibiotic administration in certain groups of patients and those with some common respiratory diagnoses. These findings help clarify the utility of rapid viral testing in the management of hospitalized pediatric patients.

Reducing the blood culture contamination rate in a pediatric emergency department and subsequent cost savings.

BACKGROUND AND OBJECTIVE: Blood culture contamination in the pediatric population remains a significant quality and safety issue because false-positive blood cultures lead to unnecessary use of resources and testing. In addition, few studies describe interventions to reduce peripheral blood culture contamination rates in this population. We hypothesized that the introduction of a standardized sterile collection process would reduce the pediatric emergency department's peripheral blood culture contamination rate and unnecessary use of resources. METHODS: A sterile blood culture collection process was designed by analyzing current practice and identifying areas in which sterile technique could be introduced. To spread the new technique, a web-based educational model was developed and disseminated. Subsequently, all nursing staff members were expected to perform peripheral blood cultures by using the modified sterile technique. RESULTS: The peripheral blood culture contamination rate was reduced from 3.9% during the baseline period to 1.6% during the intervention period (P < .0001), with yearly estimated savings of ~$250,000 in hospital charges. CONCLUSIONS: Subsequent to our intervention, there was a significant reduction of the peripheral blood culture contamination rate as well as considerable cost savings to the institution. When performed in a standardized fashion by using sterile technique, blood culture collection with low contamination rates can be performed via the insertion of an intravenous catheter.

Preventability of early readmissions at a children's hospital.

OBJECTIVE: To determine whether pediatric readmissions within 15 days of discharge were considered preventable. METHODS: Retrospective chart review of 200 randomly selected readmissions (8% of all readmissions) occurring within 15 days of discharge from a freestanding children's hospital between January 1, 2007, and December 31, 2008. The degree of preventability was assessed independently for each case by 4 pediatricians using a 5-point Likert scale and was correlated with chronic conditions and reason for index admission with 3M's Clinical Risk Groups and All Patient-Refined Diagnostic-Related Groups, respectively. RESULTS: The rate of 15-day readmissions considered more likely preventable by the discharging hospital was 20.0% (1.7% of total admissions, 95% confidence interval 14.8%-26.4%). Reviewers failed to reach initial consensus in 62.5% of cases, although final consensus was achieved after the panel reviewed cases together. Consensus ratings served as the standard for the remainder of the study. Readmissions in children with malignancies were considered less preventable than those in children with other chronic illnesses (5.8% vs 25.8%, P = .003). Readmissions following surgical admissions were considered more likely preventable than those following medical admissions (38.9% vs 15.9%, P = .002). Central venous catheter infections and ventricular shunt malfunctions accounted for 8.5% of all readmissions reviewed. CONCLUSIONS: Although initial consensus about which readmissions were more likely preventable was difficult to achieve, the overall rate of preventable pediatric 15-day readmissions was low. Pediatric readmissions are unlikely to serve as a highly productive focus for cost savings or quality measurement.

Discordant antibiotic therapy and length of stay in children hospitalized for urinary tract infection.

BACKGROUND: Urinary tract infections (UTIs) are a common reason for pediatric hospitalizations. OBJECTIVE: To determine the effect of discordant antibiotic therapy (in vitro nonsusceptibility of the uropathogen to initial antibiotic) on clinical outcomes for children hospitalized for UTI. DESIGN/SETTING: Multicenter retrospective cohort study in children aged 3 days to 18 years, hospitalized at 5 children's hospitals with a laboratory-confirmed UTI. Data were obtained from medical records and the Pediatric Hospital Information System (PHIS) database. PARTICIPANTS: Patients with laboratory-confirmed UTI. MAIN EXPOSURE: Discordant antibiotic therapy. MEASUREMENTS: Length of stay and fever duration. Covariates included age, sex, insurance, race, vesicoureteral reflux, antibiotic prophylaxis, genitourinary abnormality, and chronic care conditions. RESULTS: The median age of the 216 patients was 2.46 years (interquartile range [IQR]: 0.27, 8.89) and 25% were male. The most common causative organisms were E. coli and Klebsiella species. Discordant therapy occurred in 10% of cases and most commonly in cultures positive for Klebsiella species, Enterobacter species, and mixed organisms. In adjusted analyses, discordant therapy was associated with a 1.8 day (95% confidence interval [CI]: 1.5, 2.1) longer length of stay [LOS], but not with fever duration. CONCLUSIONS: Discordant antibiotic therapy for UTI is common and associated with longer hospitalizations. Further research is needed to understand the clinical factors contributing to the increased LOS and to inform decisions for empiric antibiotic selection in children with UTIs.

Reduction in pediatric identification band errors: a quality collaborative.

BACKGROUND AND OBJECTIVE: Accurate and consistent placement of a patient identification (ID) band is used in health care to reduce errors associated with patient misidentification. Multiple safety organizations have devoted time and energy to improving patient ID, but no multicenter improvement collaboratives have shown scalability of previously successful interventions. We hoped to reduce by half the pediatric patient ID band error rate, defined as absent, illegible, or inaccurate ID band, across a quality improvement learning collaborative of hospitals in 1 year. METHODS: On the basis of a previously successful single-site intervention, we conducted a self-selected 6-site collaborative to reduce ID band errors in heterogeneous pediatric hospital settings. The collaborative had 3 phases: preparatory work and employee survey of current practice and barriers, data collection (ID band failure rate), and intervention driven by data and collaborative learning to accelerate change. RESULTS: The collaborative audited 11377 patients for ID band errors between September 2009 and September 2010. The ID band failure rate decreased from 17% to 4.1% (77% relative reduction). Interventions including education of frontline staff regarding correct ID bands as a safety strategy; a change to softer ID bands, including "luggage tag" type ID bands for some patients; and partnering with families and patients through education were applied at all institutions. CONCLUSIONS: Over 13 months, a collaborative of pediatric institutions significantly reduced the ID band failure rate. This quality improvement learning collaborative demonstrates that safety improvements tested in a single institution can be disseminated to improve quality of care across large populations of children.

Pediatric observation status: are we overlooking a growing population in children's hospitals?

BACKGROUND: Inpatient administrative datasets often exclude observation stays, as observation is considered to be outpatient care. The extent to which this status is applied to pediatric hospitalizations is not known. OBJECTIVE: To characterize trends in observation status code utilization and 1-day stays among children admitted from the emergency department (ED), and to compare patient characteristics and outcomes associated with observation versus inpatient stays. DESIGN: Retrospective longitudinal analysis of the 2004-2009 Pediatric Health Information System (PHIS). SETTING: Sixteen US freestanding children's hospitals contributing outpatient and inpatient data to PHIS. PATIENTS: Admissions to observation or inpatient status following ED care in study hospitals. MEASUREMENTS: Proportions of observation and 1-day stays among all admissions from the ED were calculated each year. Top ranking discharge diagnoses and outcomes of observation were determined. Patient characteristics, discharge diagnoses, and return visits were compared for observation and 1-day stays. RESULTS: The proportion of short-stays (including both observation and 1-day stays) increased from 37% to 41% between 2004 and 2009. Since 2007, observation stays have outnumbered 1-day stays. In 2009, more than half of admissions from the ED for 6 of the top 10 ranking discharge diagnoses were short-stays. Fewer than 25% of observation stays converted to inpatient status. Return visits and readmissions following observation were no more frequent than following 1-day stays. CONCLUSIONS: Children admitted under observation status make up a substantial proportion of acute care hospitalizations. Analyses of inpatient administrative databases that exclude observation stays likely result in an underestimation of hospital resource utilization for children.

Differences in designations of observation care in US freestanding children's hospitals: are they virtual or real?

OBJECTIVE: To characterize practices related to observation care and to examine the current models of pediatric observation medicine in US children's hospitals. DESIGN: We utilized 2 web-based surveys to examine observation care in the 42 hospitals participating in the Pediatric Health Information System database. We obtained information regarding the designation of observation status, including the criteria used to admit patients into observation. From hospitals reporting the use of observation status, we requested specific details relating to the structures of observation care and the processes of care for observation patients following emergency department treatment. RESULTS: A total of 37 hospitals responded to Survey 1, and 20 hospitals responded to Survey 2. Designated observation units were present in only 12 of 31 (39%) hospitals that report observation patient data to the Pediatric Health Information System. Observation status was variably defined in terms of duration of treatment and prespecified criteria. Observation periods were limited to <48 hours in 24 of 31 (77%) hospitals. Hospitals reported that various standards were used by different payers to determine observation status reimbursement. Observation care was delivered in a variety of settings. Most hospitals indicated that there were no differences in the clinical care delivered to virtual observation status patients when compared with other inpatients. CONCLUSIONS: Observation is a variably applied patient status, defined differently by individual hospitals. Consistency in the designation of patients under observation status among hospitals and payers may be necessary to compare quality outcomes and costs, as well as optimize models of pediatric observation care.

Inpatient capacity at children's hospitals during pandemic (H1N1) 2009 outbreak, United States.

Quantifying how close hospitals came to exhausting capacity during the outbreak of pandemic influenza A (H1N1) 2009 can help the health care system plan for more virulent pandemics. This ecologic analysis used emergency department (ED) and inpatient data from 34 US children's hospitals. For the 11-week pandemic (H1N1) 2009 period during fall 2009, inpatient occupancy reached 95%, which was lower than the 101% occupancy during the 2008-09 seasonal influenza period. Fewer than 1 additional admission per 10 inpatient beds would have caused hospitals to reach 100% occupancy. Using parameters based on historical precedent, we built 5 models projecting inpatient occupancy, varying the ED visit numbers and admission rate for influenza-related ED visits. The 5 scenarios projected median occupancy as high as 132% of capacity. The pandemic did not exhaust inpatient bed capacity, but a more virulent pandemic has the potential to push children's hospitals past their maximum inpatient capacity.

Accuracy of administrative billing codes to detect urinary tract infection hospitalizations.

BACKGROUND: Hospital billing data are frequently used for quality measures and research, but the accuracy of the use of discharge codes to identify urinary tract infections (UTIs) is unknown. OBJECTIVE: To determine the accuracy of International Classification of Diseases, 9th revision (ICD-9) discharge codes to identify children hospitalized with UTIs. METHODS: This multicenter study conducted in 5 children's hospitals included children aged 3 days to 18 years who had been admitted to the hospital, undergone a urinalysis or urine culture, and discharged from the hospital. Data were obtained from the pediatric health information system database and medical record review. With the use of 2 gold-standard methods, the positive predictive value (PPV) was calculated for individual and combined UTI codes and for common UTI identification strategies. PPV was measured for all groupings for which the UTI code was the principal discharge diagnosis. RESULTS: There were 833 patients in the study. The PPV was 50.3% with the use of the gold standard of laboratory-confirmed UTIs but increased to 85% with provider confirmation. Restriction of the study cohort to patients with a principle diagnosis of UTI improved the PPV for laboratory-confirmed UTI (61.2%) and provider-confirmed UTI (93.2%), as well as the ability to benchmark performance. Other common identification strategies did not markedly affect the PPV. CONCLUSIONS: ICD-9 codes can be used to identify patients with UTIs but are most accurate when UTI is the principal discharge diagnosis. The identification strategies reported in this study can be used to improve the accuracy and applicability of benchmarking measures.

Addressing inpatient crowding by smoothing occupancy at children's hospitals.

OBJECTIVE: To quantify the difference in weekday versus weekend occupancy, and the opportunity to smooth inpatient occupancy to reduce crowding at children's hospitals. METHODS: Daily inpatient census data for 39 freestanding, tertiary-care children's hospitals were used to calculate occupancy and to model the impact of reducing variation in occupancy and the change in the number of patients, patient-days, and hospitals exposed to high occupancy pre- and post-smoothing. We also calculated the proportion of weekly admissions that would require different scheduling to achieve within-week smoothing. RESULTS: Overall, hospitals' mean occupancy ranged from 70.9% to 108.1% on weekdays, and 65.7% to 94.9% on weekends. Weekday occupancy exceeded weekend occupancy with a median difference of 8.2% points. The mean post-smoothing reduction in weekly maximum occupancy across all hospitals was 6.6% points. Through smoothing, 39,607 patients from the 39 hospitals were removed from exposure to occupancy levels >95%. To achieve within-week smoothing, a median 2.6% of admissions would have to be scheduled on a different day of the week; this equates to a median of 7.4 patients per week (range: 2.3-14.4). CONCLUSION: Hospitals do have substantial unused capacity, and smoothing occupancy over the course of a week could be a useful strategy that hospitals can use to reduce crowding and protect patients from crowded conditions.

Epidemiology of 15-Day Readmissions to a Children's Hospital.

OBJECTIVE: To describe the population of pediatric patients readmitted to a children's hospital within 15 days of discharge. PATIENTS AND METHODS: Medical records were reviewed to identify characteristics of patients and their hospitalizations for all children hospitalized during calendar years 2007-2008 who were readmitted up to and including 15 days after a previous discharge. RESULTS: Of 30 188 total hospital admissions during the study period, 2546 (8.4%) were followed by a readmission within 15 days of discharge. The age groups with the greatest number of readmissions were infants (aged 31-364 days, 20.8% of readmissions) and patients aged >10 years (31.3% of readmissions). Most readmitted patients (78.0%) had an underlying chronic illness, and patients with malignancies were most likely to be readmitted, followed by newborns and patients with neurologic conditions. Patients with malignancies also experienced the greatest number of readmissions per patient (4.1). Most patients who were readmitted had only 1 readmission (71.5%), but the small subset of patients with 3 or more readmissions accounted for 43.7% of all 15-day readmissions. Disease recurrence and natural course of the original diagnosis were the most common reasons for readmission (44.9%), followed by planned readmissions (20.6%) and readmissions for a new, unrelated illness (7.7%). CONCLUSIONS: This report is the first description of the epidemiology of all 15-day pediatric readmissions at a children's hospital. The results of this study serve as a basis for additional analysis to determine the extent to which readmissions in the pediatric population may or may not be preventable.