<p><strong>BACKGROUND AND OBJECTIVES: </strong>Hospitals treating patients with greater diagnosis diversity may have higher fixed and overhead costs. We assessed the relationship between hospitals' diagnosis diversity and cost per hospitalization for children.</p>

<p><strong>METHODS: </strong>Retrospective analysis of 1 654 869 all-condition hospitalizations for children ages 0 to 21 years from 2816 hospitals in the Kids' Inpatient Database 2016. Mean hospital cost per hospitalization, Winsorized and log-transformed, was assessed for freestanding children's hospitals (FCHs), nonfreestanding children's hospitals (NFCHs), and nonchildren's hospitals (NCHs). Hospital diagnosis diversity index (HDDI) was calculated by using the D-measure of diversity in Shannon-Wiener entropy index from 1254 diagnosis and severity-of-illness groups distinguished with 3M Health's All Patient Refined Diagnosis Related Groups. Log-normal multivariable models were derived to regress hospital type on cost per hospitalization, adjusting for hospital-level HDDI in addition to patient-level demographic (eg, age, race and ethnicity) and clinical (eg, chronic conditions) characteristics and hospital teaching status.</p>

<p><strong>RESULTS: </strong>Admission counts were 383 789 (23.2%) in FCHs, 588 463 (35.6%) in NFCHs, and 682 617 (41.2%) in NCHs. Unadjusted mean cost per hospitalization was $10 757 (95% confidence interval [CI]: $9451 to $12 243) in FCHs, $6264 (95% CI: $5830 to $6729) in NFCHs, and $4192 (95% CI: $4121 to $4265) in NCHs. HDDI was significantly ( &lt; .001) higher in FCHs and NFCHs (median 9.2 and 6.4 times higher, respectively) than NCHs. Across all hospitals, greater HDDI was associated ( = .002) with increased cost. Adjusting for HDDI resulted in a nonsignificant ( = .1) difference in cost across hospital types.</p>

<p><strong>CONCLUSIONS: </strong>Greater diagnosis diversity was associated with increased cost per hospitalization and should be considered when assessing associated costs of inpatient care for pediatric patients.</p>

<p><strong>OBJECTIVE: </strong>To assess the timing of pediatric asthma rehospitalization, variation in rate of rehospitalization across hospitals, and factors associated with rehospitalization at different intervals.</p>

<p><strong>STUDY DESIGN: </strong>Retrospective cohort analysis of 44,204 hospitalizations for children with asthma within 42 children's hospitals between July 2008 and June 2011. The main outcome measures were rehospitalization for asthma within 7, 15, 30, 60, 180, and 365 days of an index asthma admission.</p>

<p><strong>RESULTS: </strong>The rate of asthma rehospitalization ranged from 0.5% (n = 208) at 7 days to 17.2% (n = 7603) at 365 days. Black patients and patients with public insurance had higher odds of rehospitalization at 60 days and beyond (P ≤ .01 for both). Adolescents (12- to 18-year-old), patients with a diagnosis of a complex chronic condition, and patients with a prior year asthma admission had higher odds of rehospitalization at every time interval (P ≤ .001 for all). Significant hospital variation in case-mix adjusted rates of rehospitalization existed at each time interval (P ≤ .01 for all). Rates at 365 days were ≤ 10.9% for the top 10% of hospitals; if all hospitals achieved this rate, 36.6% of rehospitalizations might have been avoided.</p>

<p><strong>CONCLUSIONS: </strong>Significant variation in asthma rehospitalization rates exists across children's hospitals from 7 to 365 days after an index admission. Racial/ethnic and economic disparities emerge at 60 days. By 1 year, rehospitalizations account for 1 in 6 hospitalizations. Assessing asthma rehospitalizations at longer intervals may augment our current understanding of and approach to post-hospitalization care improvement.</p>