Obesity and 1-year outcomes in older Americans with severe sepsis.
OBJECTIVE
Although critical care physicians view obesity as an independent poor prognostic marker, growing evidence suggests that obesity is, instead, associated with improved mortality following ICU admission. However, this prior empirical work may be biased by preferential admission of obese patients to ICUs, and little is known about other patient-centered outcomes following critical illness. We sought to determine whether 1-year mortality, healthcare utilization, and functional outcomes following a severe sepsis hospitalization differ by body mass index.


METHODS
Observational cohort study.


METHODS
U.S. hospitals.


METHODS
We analyzed 1,404 severe sepsis hospitalizations (1999-2005) among Medicare beneficiaries enrolled in the nationally representative Health and Retirement Study, of which 597 (42.5%) were normal weight, 473 (33.7%) were overweight, and 334 (23.8%) were obese or severely obese, as assessed at their survey prior to acute illness. Underweight patients were excluded a priori.


METHODS
None.


RESULTS
Using Medicare claims, we identified severe sepsis hospitalizations and measured inpatient healthcare facility use and calculated total and itemized Medicare spending in the year following hospital discharge. Using the National Death Index, we determined mortality. We ascertained pre- and postmorbid functional status from survey data. Patients with greater body mass indexes experienced lower 1-year mortality compared with nonobese patients, and there was a dose-response relationship such that obese (odds ratio = 0.59; 95% CI, 0.39-0.88) and severely obese patients (odds ratio = 0.46; 95% CI, 0.26-0.80) had the lowest mortality. Total days in a healthcare facility and Medicare expenditures were greater for obese patients (p < 0.01 for both comparisons), but average daily utilization (p = 0.44) and Medicare spending were similar (p = 0.65) among normal, overweight, and obese survivors. Total function limitations following severe sepsis did not differ by body mass index category (p = 0.64).


CONCLUSIONS
Obesity is associated with improved mortality among severe sepsis patients. Due to longer survival, obese sepsis survivors use more healthcare and result in higher Medicare spending in the year following hospitalization. Median daily healthcare utilization was similar across body mass index categories.
1Department of Medicine, University of Michigan, Ann Arbor, MI. 2Steindhart School of Culture, Education, and Human Development, New York University, New York, NY. 3Riverside Methodist Hospital, Columbus, OH. 4VA Center for Clinical Management Research, HSR&D Center for Excellence, Ann Arbor, MI. 5Institute for Social Research, Ann Arbor, MI.
Hallie C
HC
Prescott
Virginia W
VW
Chang
James M
JM
O'Brien
Kenneth M
KM
Langa
Theodore J
TJ
Iwashyna
D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D015331:Cohort Studies; D015897:Comorbidity; D016638:Critical Illness; D003695:Delivery of Health Care / Q000706:statistics & numerical data*; D005260:Female; D005102:Health Expenditures / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D006278:Medicare / Q000191:economics* / Q000706:statistics & numerical data; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology*; D018805:Sepsis / Q000401:mortality*; D015996:Survival Rate; D017741:Survivors / Q000706:statistics & numerical data; D014481:United States