Septicemia, an illness caused by blood infections with bacteria such as E. coli and methicillin-resistant Staphylococcus aureus (MRSA), was the single most expensive condition treated in U.S. hospitals at nearly $15.4 billion in 2009, according to the latest News and Numbers from the Agency for Healthcare Research and Quality (AHRQ). Data include cases of septicemia acquired within the community and during hospital stays.

- The number of hospital stays principally for septicemia more than doubled between 2000 and 2009 (337,100 admissions and 836,000 admissions, respectively), making it the sixth most common principal reason for hospitalization in 2009.

-Â Complication resulting from a device, implant or graft was the most common reason for these hospitalizations, representing one of every five septicemia-related stays.

- The in-hospital death rate for septicemia was 16 percent in 2009  more than eight times as high as for all other hospital stays.

- More than half of all patients hospitalized for septicemia were elderly; about 14 percent were 85 and older and nearly 40 percent were 65 to 84. Some 27 percent of cases were in patients age 45 to 64, nearly 11 percent were in patients age 18 to 44 and only 1.6 percent were in children age 1 to 17.

This AHRQ News and Numbers summary is based on data from Statistical Brief #122: Septicemia in U.S. Hospitals, 2009. The report uses data from the Nationwide Inpatient Sample.