Cognitive impairment and functional disability are major determinants of caregiving
needs and societal health care costs. Although the incidence of severe sepsis is high
and increasing, the magnitude of patients' long-term cognitive and functional limitations
after sepsis is unknown.
To determine the change in cognitive impairment and physical functioning among patients
who survive severe sepsis, controlling for their presepsis functioning.
A prospective cohort involving 1194 patients with 1520 hospitalizations for severe
sepsis drawn from the Health and Retirement Study, a nationally representative survey
of US residents (1998-2006). A total of 9223 respondents had a baseline cognitive
and functional assessment and had linked Medicare claims; 516 survived severe sepsis
and 4517 survived a nonsepsis hospitalization to at least 1 follow-up survey and are
included in the analysis.
Personal interviews were conducted with respondents or proxies using validated surveys
to assess the presence of cognitive impairment and to determine the number of activities
of daily living (ADLs) and instrumental ADLs (IADLs) for which patients needed assistance.
Survivors' mean age at hospitalization was 76.9 years. The prevalence of moderate
to severe cognitive impairment increased 10.6 percentage points among patients who
survived severe sepsis, an odds ratio (OR) of 3.34 (95% confidence interval [CI],
1.53-7.25) in multivariable regression. Likewise, a high rate of new functional limitations
was seen following sepsis: in those with no limits before sepsis, a mean 1.57 new
limitations (95% CI, 0.99-2.15); and for those with mild to moderate limitations before
sepsis, a mean of 1.50 new limitations (95% CI, 0.87-2.12). In contrast, nonsepsis
general hospitalizations were associated with no change in moderate to severe cognitive
impairment (OR, 1.15; 95% CI, 0.80-1.67; P for difference vs sepsis = .01) and with
the development of fewer new limitations (mean among those with no limits before hospitalization,
0.48; 95% CI, 0.39-0.57; P for difference vs sepsis <.001 and mean among those with
mild to moderate limits, 0.43; 95% CI, 0.23-0.63; P for difference = .001). The declines
in cognitive and physical function persisted for at least 8 years.
Severe sepsis in this older population was independently associated with substantial
and persistent new cognitive impairment and functional disability among survivors.
The magnitude of these new deficits was large, likely resulting in a pivotal downturn
in patients' ability to live independently.