Epidemiology, complications, and cost of hospitalization in children with laboratory-confirmed influenza infection.
BACKGROUND
Influenza causes significant morbidity among children. Previous studies used indirect case ascertainment methods with little cost data. We sought to measure the burden of laboratory-confirmed influenza from hospitalized children.


METHODS
We conducted a retrospective cohort study during 3 viral seasons at Primary Children's Medical Center (Salt Lake City, UT). Children < or = 18 years of age who were hospitalized with laboratory-confirmed influenza infection were included. Outcomes included hospitalization rates, complications including intensive care unit stays, mechanical ventilation, length of stay, and total hospital costs.


RESULTS
A total of 325 children had hospitalizations attributable to influenza over 3 viral seasons: 28% < 6 months of age, 33% between 6 and 23 months of age; and 39% > 2 years of age; 37% had high-risk medical conditions. Population-based rates of hospitalization for Salt Lake County residents ranged from 6.3 to 252.7 per 100,000 children. The highest rates were in children younger than 6 months, and rates decreased with increasing age. Forty-nine (15%) children had an ICU stay; 27 required mechanical ventilation, and half of these patients were > 2 years of age. Total hospital cost for the cohort was 2 million dollars; 55% was accounted for by children > 2 years of age. Length of stay and total hospital costs were significantly higher in all children > 2 years of age compared with children < 6 months of age and were comparable to all children 6 to 23 months of age.


CONCLUSIONS
Proven influenza infection in children results in substantial hospital resource utilization and morbidity. Nationwide, the median hospital costs may total 55 million dollars. Our data support the Advisory Committee on Immunization's recommendations to expand the use of influenza vaccine to children > 2 years of age.
Ampofo
Krow
K
Division of Pediatric Infectious Disease, University of Utah Health Sciences Center, 30 North 1900 E, Room 2A100, Salt Lake City, UT 84132, USA. krow.ampofo@hsc.utah.edu
Gesteland
Per H
PH
Bender
Jeffery
J
Mills
Michelle
M
Daly
Judy
J
Samore
Matthew
M
Byington
Carrie
C
Pavia
Andrew T
AT
Srivastava
Rajendu
R
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003365:Costs and Cost Analysis; D005260:Female; D006760:Hospitalization / Q000191:economics*; D006801:Humans; D007223:Infant; D007251:Influenza, Human / Q000150:complications* / Q000191:economics / Q000453:epidemiology* / Q000628:therapy; D008297:Male; D012189:Retrospective Studies