Population burden of long-term survivorship after severe sepsis in older Americans

Objectives: To ascertain the absolute number of Medicare beneficiaries surviving at least 3 years after severe sepsis and to estimate their burden of cognitive dysfunction and disability.

Design: Retrospective cohort analysis of Medicare data.

Setting: All short-stay inpatient hospitals in the United States, 1996 to 2008.

Participants: Individuals aged 65 and older.

Measurements: Severe sepsis was detected using a standard administrative definition. Case-fatality, prevalence, and incidence rates were calculated.

Results: Six hundred thirty-seven thousand eight hundred sixty-seven Medicare beneficiaries were alive at the end of 2008 who had survived severe sepsis 3 or more years earlier. An estimated 476,862 (95% confidence interval (CI) = 455,026-498,698) had functional disability, with 106,311 (95% CI = 79,692-133,930) survivors having moderate to severe cognitive impairment. The annual number of new 3-year survivors after severe sepsis rose 119% during 1998 to 2008. The increase in survivorship resulted from more new diagnoses of severe sepsis rather than a change in case-fatality rates; severe sepsis rates rose from 13.0 per 1,000 Medicare beneficiary-years to 25.8 (P < .001), whereas 3-year case fatality rates changed much less, from 73.5% to 71.3% (P < .001) for the same cohort. Increasing rates of organ dysfunction in hospitalized individuals drove the increase in severe sepsis incidence, with an additional small contribution from population aging.

Conclusions: Sepsis survivorship, which has substantial long-term morbidity, is a common and rapidly growing public health problem for older Americans. There has been little change in long-term case-fatality, despite changes in practice. Clinicians should anticipate more-frequent sequelae of severe sepsis in their patient populations.