Socioeconomic Burden of Influenza in the Republic of Korea, 2007-2010

Background: Although the socioeconomic burden of 2009 pandemic influenza A (H1N1) was considerable, no reliable estimates have been reported. Our aim was to compared medical costs and socioeconomic burden resulting from pandemic influenza A (H1N1) 2009 with that of previous seasonal influenza. Methods: We estimated the medical costs and socioeconomic burden of influenza from May 2007 to April 2010. We used representative national data sources(data from the Health Insurance Review Agency, the National Health Insurance Corporation, the Korea Centers for Disease Control and Prevention, and the Korean National Statistics Office) including medical utilization, prescription of antivirals, and vaccination. Uncertainty of data was explored through sensitivity analysis using Monte Carlo simulation. Results: Compared with the seasonal influenza, total medical costs (US$291.7 million) associated with pandemic (H1N1) 2009 increased more than 37-fold. Compared with the 2007-2008 season, outpatient diagnostic costs (US$135.3 million) were 773 times higher in the 2009-2010 season, and the mean diagnostic cost per outpatient visit was 58.8 times higher. Total socioeconomic burden of pandemic (H1N1) 2009 was estimated at US$1581.3 million (10%-90%: US$1436.0-1808.3 million) and those of seasonal influenza was estimated at US$44.7 million (10%-90%: US$32.4-57.9 million) in 2007-2008 season and US$42.3 million (10%-90%: US$31.5-53.8 million) in 2008-2009 season. Indirect costs accounted for 56.0% of total costs in pandemic (H1N1) 2009, and 66.48-68.09% in seasonal influenza. The largest contributors to total burden were productivity losses of caregiver in pandemic (H1N1) 2009, and productivity losses due to morbidity of outpatient in seasonal influenza. Conclusions: In the Republic of Korea, socioeconomic burden of pandemic (H1N1) 2009 were considerably higher than burden of the previous two influenza seasons, primarily because of high diagnostic costs and longer sick leave.