Implications of Obesity for the General Medicine Inpatient

1Northwestern University, Chicago, IL
2Northwestern University, Chicago, IL
3Northwestern University, Chicago, IL

Meeting: Hospital Medicine 2010, April 8-11, Washington, D.C.

Abstract number: 149


The long‐term health consequences related to obesity are well documented. Recent surgical and intensive care unit literature has reported no significant differences in morbidity or mortality related to obesity. However, the full consequences of obesity itself for the general medicine inpatient are unknown. This study sought to determine the effect of obesity on hospital‐relevant outcomes for general medicine patients.


Utilizing our enterprise data warehouse, we conducled a retrospective chart review from September 2006 through September 2008 of general medicine patients admitted to Northwestern Memorial Hospital (NMH) in Chicago, Illinois. Body mass index (BMI) was calculated on admission for all in patients using traditional formulas [BMI (kg/m2) = weight (kg)/height2 (m2)] from information input by nurses into the electronic medical record. Patients were excluded if they had a BMI less than 18.5. Patients were classified into groups based on calculated BMI. Groups were as follows: 18.5 ≤ BMI < 25, 25 ≤ BMI ≤ 30, 30 ≤ BMI < 35, 35 ≤ BMI < 40, and BMI ≥ 40. Hospital relevant outcomes included length of stay, transfer to the intensive care unit (ICU), and 30‐day readmission rates. All outcomes were adjusted for patient age and Charlson score. SAS was used to con‐duct all statistical analyses.


Between September 1,2006, and September 1,2008, a total of 11,948 patients were admitted to the general medicine service at NMH. After excluding those patients with a BMI < 18.5, 11,235 eligible patients were included in the analysis. Of these, 35.1% of patients (3942) met criteria for obesity (BMI > 30). The study population was 54.5% (6124) female with an average age of 60.2 ± 18.7 years. Unadjusted analysis showed that patients with a BMI ≥ 40 were more likely to be readmitted within 30 days (P = 0.05) compared to those with a BMI < 40. The difference in readmission rates between BMI ranges persisted after adjusting for both age and Charlson score (P = 0.04). Outcomes were similar across BMI ranges < 40. No significant differences were found between BMI and length of stay (P = 0.36) or risk of ICU transfer during admission (P = 0.07).


Obese inpatients. particularly those with a BMI > 40, do appear to have higher rates of 30‐day readmission. However, increasing BMI does not significantly affect length of hospital stay or risk of transfer to the ICU.

Author Disclosure:

K. Wachsberg, none; M. Tipping, none; M. Williams, none.

To cite this abstract:

Wachsberg K, Tipping M, Williams M. Implications of Obesity for the General Medicine Inpatient. Abstract published at Hospital Medicine 2010, April 8-11, Washington, D.C. Abstract 149. Journal of Hospital Medicine. 2010; 5 (suppl 1). Accessed April 9, 2020.

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