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.