Differences in cost and hospital days between treatment groups will be assessed using generalized linear models with log-link and gamma distribution. The model will include treatment group (intervention/control), time (5 periods), season, age, ethnicity, insurance status, baseline patient risk , time of hospital admission (day on weekdays: 8 am - 5 pm; weekday night; weekend) as covariates, and will account for correlations within patient. The incremental cost (savings) of hospitalist care will be computed by subtracting the mean cost per patient in this group from the mean cost per patient in the general pediatrics group. The incremental cost-effectiveness ratio will be computed by dividing the incremental costs (savings) by the hospital days avoided. The investigators will also assess the robustness of the results in sensitivity analyses by assessing the joint influence of hospitalists care on both cost and effectiveness using the net monetary benefit approach.