Ambulatory CareHospitalizationIntensive Care UnitsIntensive CareOutpatient Clinics, HospitalIntensive Care Units, NeonatalIntensive Care Units, PediatricLength of StayRetrospective StudiesTreatment OutcomeProspective StudiesUnited StatesRisk FactorsIntensive Care, NeonatalInfant, NewbornPatient DischargeCohort StudiesTime FactorsFollow-Up StudiesHealth Care CostsIncidencePatient AdmissionPatient ReadmissionSeverity of Illness IndexHospital CostsHeart FailureInpatientsAmbulatory Care FacilitiesHospital MortalityCritical IllnessAmbulatory Surgical ProceduresAge FactorsPneumoniaComorbidityEmergency Service, HospitalRisk Assessment