Length of Stay and Complications Associated With Febrile Infants <90 Days of Age Hospitalized in the United States, 2000-2012.

OBJECTIVES: It is not known how changes in the epidemiology of serious bacterial infection (SBI) and greater availability of rapid viral diagnostic tests have impacted the hospital length of stay (LOS) and associated complications among young infants with suspected SBI.

METHODS: We used national administrative data from the Healthcare Cost and Utilization Project Kids' Inpatient Database and other state-specific data to identify febrile infants <90 days of age hospitalized in 2000, 2003, 2006, 2009, and 2012. We used multivariate analysis to determine LOS, risk factors for prolonged LOS, and complications of care among infants with isolated fever or viral respiratory disease, without concomitant serious infection.

RESULTS: We identified 44 875 infants. LOS for each clinical group did not change over time in a clinically significant way. Mean LOS was ≤2 days for approximately two-thirds of all infants and ≥4 days for 11% in each clinical group. Factors associated with longer LOS included age <31 days, critical clinical status, concomitant chronic disease, and the presence of complications ( P < .05). We identified 289 (0.8%) infants with 351 complications of care, 18 (6%) of whom had >1. These infants had longer LOS ( P < .001), and those with chronic disease and older age were at increased risk ( P < .01).

CONCLUSIONS: Despite the changing epidemiology of SBI and increased availability of viral diagnostic testing, we did not detect a clinically significant change in LOS for febrile infants with suspected SBI. Complications associated with hospitalization of these infants was associated with increased LOS.