Pneumonia and influenza hospitalizations among children under 5 years of age in Suzhou, China, 2005–2011

BACKGROUND: The disease burden of influenza among children in China has not been well described. OBJECTIVE: To estimate the influenza‐associated excess hospitalization rate and compare the hospitalization length and costs between pneumonia and influenza (P&I) and other community‐acquired diseases (CAD) in Suzhou, China. METHODS: We retrospectively collected hospital discharge data on pediatric patients' discharge diagnosis, hospital costs, and length of hospital stay in Suzhou. P&I hospitalization was defined as a primary discharge diagnosis of pneumonia and influenza disease (ICD‐10 codes J09–J18). Other CAD were common community‐acquired diseases among children. Negative binomial regression models were used to estimate the weekly P&I hospitalizations in Suzhou. Excess P&I hospitalizations due to influenza were calculated as the difference in P&I hospitalizations between the epidemic period and the baseline period. Baseline was defined as when the influenza‐positive rates were <5% for two consecutive weeks. RESULTS: From October 2005 to September 2011, we identified a total of 180 091 all‐cause hospitalizations among children <5 years of age in Suzhou City. The rates of P&I and influenza‐associated excess hospitalizations were highest in the 2009–2010 pandemic and 2010–2011 post‐pandemic seasons. Infants <6 months of age had the highest P&I hospitalization rates, the longest hospital stays (7.5–8.0 days), and the highest hospitalization costs for P&I. Compared with other CAD, children admitted for P&I had longer hospital stays and higher hospitalization costs. CONCLUSIONS: The influenza‐associated P&I hospitalization rates and economic burden were high among children. Targeted influenza prevention and control strategies for young children in Suzhou may reduce the influenza‐associated hospitalizations in this age group.