The Clinical Characteristics and Direct Medical Cost of Influenza in Hospitalized Children: A Five-Year Retrospective Study in Suzhou, China

Background: There have been few studies on children hospitalized with influenza published from mainland China. We performed a retrospective review of medical charts to describe the epidemiology, clinical features and direct medical cost of laboratory-proven influenza hospitalized children in Suzhou, China. Methods: Retrospective study on children with documented influenza infection hospitalized at Suzhou Children Hospital during 2005-2009 was conducted using a structured chart review instrument. Results: A total of 480 children were positive by immuno-fluorescent assay for influenza during 2005-2009. The hospitalizations for influenza occurred in 8-12 months of the year, most commonly in the winter with a second late summer peak (August-September). Influenza A accounted for 86.3%, and of these 286 (59.6%) were male, and 87.2% were <5 years of age. The median length of hospital stay was 7 days. Fever was the most common symptom, occurring in 398 (82.9%) children. There were 394 (82.1%) children with pneumonia and 70.2% of these hospitalized children had radiographic evidence of a pulmonary infiltrate. One hundred and twelve children (23.3%) required oxygen treatments and 13 (2.7%) were transferred to the ICU. Multivariable logistic regression showed that compared with the <= 6 months children, those aged >60 months old had shorter hospital stay (OR = 0.45); children with oxygen treatment tended to have longer hospital stays than those without oxygen treatment (OR = 2.14). The mean cost of each influenza-related hospitalization was US$ 624 (US$ 1323 for children referred to ICU and US$ 617 for those cared for on the wards). High risk children had higher total cost than low-risk patients. Conclusion: Compared to other countries, in Suzhou, children hospitalized with influenza have longer hospital stay and higher percentage of pneumonia. The direct medical cost is high relative to family income. Effective strategies of influenza immunization of young children in China may be beneficial in addressing this disease burden.