SAN DIEGO — The rising incidence of severe sepsis in the past 2 decades has been accompanied by a decline in the case fatality rate, Charmaine Lewis, M.D., reported in a poster session at the 100th International Conference of the American Thoracic Society.
The incidence of severe sepsis in the United States rose from about 10 cases per 100,000 people in 1979 to 106 cases per 100,000 people in 2002.
“Severe sepsis is a common diagnosis for ICU admission—it's the 10th most common cause of death in the United States, and it's increasing in incidence,” Dr. Lewis told FAMILY PRACTICE NEWS.
Key reasons for the increase since 1979, she said, include the emergence of HIV and the aging population. In addition, “we use a lot more immunosuppressive agents to treat what we used to consider mundane problems, such as rheumatoid arthritis,” said Dr. Lewis, of the division of pulmonary, allergy, and critical care at Emory University, Atlanta.
Meanwhile, the case fatality rate among patients with severe sepsis dropped from 56% in 1979 to 36% in 2002. Fatality rates were highest among patients with respiratory, metabolic, or cardiovascular organ failure, Dr. Lewis said.
Reasons for the decline in deaths remain unclear, she said, but may have to do with improved recognition and treatment of sepsis in acute care settings.
Dr. Lewis and her associates identified patients with severe sepsis by ICD-9 codes for sepsis and acute organ dysfunction contained in National Hospital Discharge Surveys between 1979 and 2002. They normalized incidence rates to the 2002 Census.
From 1979 to 2002 there were 3,302,635 cases of severe sepsis in the United States. Over that period the incidence increased from about 10 cases per 100,000 people in 1979 to a peak of 106 cases per 100,000 people in 2002. The incidence increased about 8.1% per year between 1982 and 2002.
The average age for all patients (65 years) did not change during the study period, but it was slightly lower for men than for women (63 vs. 67 years) and was lowest for African American males (56 years).
Each year about $17 billion is spent on the care of patients with sepsis.
The National Institutes of Health funded the study.