Underweight is independently associated with mortality in post-operative and non-operative patients admitted to the intensive care unit: a retrospective study

<p>Abstract</p> <p>Background</p> <p>Low and high body mass index (BMI) have been recently shown to be associated with increased and decreased mortality after ICU admission, respectively. The objective of this study was to determine the impact of BMI on mortality and le...

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Main Authors: Afessa Bekele, Gajic Ognjen, Finkielman Javier D
Format: Article
Language:English
Published: BMC 2004-10-01
Series:BMC Emergency Medicine
Online Access:http://www.biomedcentral.com/1471-227X/4/3
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author Afessa Bekele
Gajic Ognjen
Finkielman Javier D
author_facet Afessa Bekele
Gajic Ognjen
Finkielman Javier D
author_sort Afessa Bekele
collection DOAJ
description <p>Abstract</p> <p>Background</p> <p>Low and high body mass index (BMI) have been recently shown to be associated with increased and decreased mortality after ICU admission, respectively. The objective of this study was to determine the impact of BMI on mortality and length of stay in patients admitted to the intensive care unit (ICU).</p> <p>Methods</p> <p>In this retrospective cohort study, the Acute Physiology and Chronic Health Evaluation (APACHE) III database of patients admitted to the ICUs of a tertiary academic medical center, from January 1997 to September 2002, was crossed with a Hospital Rule-based Systems database to obtain the height and weight of the patients on admission to the ICU. The cohort was divided in post-operative and non-operative groups. We created the following five subgroups based on the BMI: <18.5, 18.5 to 24.9, 25 to 29.9, 30.0 to 39.9, ≥ 40.0 Kg/m<sup>2</sup>. A multiple logistic regression analysis was used to determine the independent impact of BMI on hospital mortality. The ICU length of stay ratio was defined as the ratio of the observed to the predicted LOS. <it>P</it>-value < 0.05 was considered significant. The 95% confidence interval (CI) was calculated for the odds ratio (OR).</p> <p>Results</p> <p>BMI was available in 19,669 of the 21,790 patients in the APACHE III database; 11,215 (57%) of the patients were admitted post-operatively. BMI < 18.5 was associated with increased mortality in both post-operative (OR = 2.14, 95% CI, 1.39 to 3.28) and non-operative (OR = 1.51, 95% CI, 1.13 to 2.01) patients. Post-operative patients with a BMI between 30.0 to 39.9 had a lower mortality rate (OR = 0.68, 95% CI, 0.49 to 0.94). Post-operative patients with BMI <18.5 or BMI ≥ 40 had an ICU length of stay ratio significantly higher than patients with BMI between 18.5 to 24.9. The addition of BMI < 18.5 did not improve significantly the accuracy of our prognostic model in predicting hospital mortality.</p> <p>Conclusions</p> <p>Low BMI is associated with higher mortality in both post- and non-operative patients admitted to the ICU. LOS is increased in post-operative patients with low and high BMIs.</p>
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spelling doaj.art-add6850d81934dca8ae0d2ad5fdd0f762022-12-21T18:51:33ZengBMCBMC Emergency Medicine1471-227X2004-10-0141310.1186/1471-227X-4-3Underweight is independently associated with mortality in post-operative and non-operative patients admitted to the intensive care unit: a retrospective studyAfessa BekeleGajic OgnjenFinkielman Javier D<p>Abstract</p> <p>Background</p> <p>Low and high body mass index (BMI) have been recently shown to be associated with increased and decreased mortality after ICU admission, respectively. The objective of this study was to determine the impact of BMI on mortality and length of stay in patients admitted to the intensive care unit (ICU).</p> <p>Methods</p> <p>In this retrospective cohort study, the Acute Physiology and Chronic Health Evaluation (APACHE) III database of patients admitted to the ICUs of a tertiary academic medical center, from January 1997 to September 2002, was crossed with a Hospital Rule-based Systems database to obtain the height and weight of the patients on admission to the ICU. The cohort was divided in post-operative and non-operative groups. We created the following five subgroups based on the BMI: <18.5, 18.5 to 24.9, 25 to 29.9, 30.0 to 39.9, ≥ 40.0 Kg/m<sup>2</sup>. A multiple logistic regression analysis was used to determine the independent impact of BMI on hospital mortality. The ICU length of stay ratio was defined as the ratio of the observed to the predicted LOS. <it>P</it>-value < 0.05 was considered significant. The 95% confidence interval (CI) was calculated for the odds ratio (OR).</p> <p>Results</p> <p>BMI was available in 19,669 of the 21,790 patients in the APACHE III database; 11,215 (57%) of the patients were admitted post-operatively. BMI < 18.5 was associated with increased mortality in both post-operative (OR = 2.14, 95% CI, 1.39 to 3.28) and non-operative (OR = 1.51, 95% CI, 1.13 to 2.01) patients. Post-operative patients with a BMI between 30.0 to 39.9 had a lower mortality rate (OR = 0.68, 95% CI, 0.49 to 0.94). Post-operative patients with BMI <18.5 or BMI ≥ 40 had an ICU length of stay ratio significantly higher than patients with BMI between 18.5 to 24.9. The addition of BMI < 18.5 did not improve significantly the accuracy of our prognostic model in predicting hospital mortality.</p> <p>Conclusions</p> <p>Low BMI is associated with higher mortality in both post- and non-operative patients admitted to the ICU. LOS is increased in post-operative patients with low and high BMIs.</p>http://www.biomedcentral.com/1471-227X/4/3
spellingShingle Afessa Bekele
Gajic Ognjen
Finkielman Javier D
Underweight is independently associated with mortality in post-operative and non-operative patients admitted to the intensive care unit: a retrospective study
BMC Emergency Medicine
title Underweight is independently associated with mortality in post-operative and non-operative patients admitted to the intensive care unit: a retrospective study
title_full Underweight is independently associated with mortality in post-operative and non-operative patients admitted to the intensive care unit: a retrospective study
title_fullStr Underweight is independently associated with mortality in post-operative and non-operative patients admitted to the intensive care unit: a retrospective study
title_full_unstemmed Underweight is independently associated with mortality in post-operative and non-operative patients admitted to the intensive care unit: a retrospective study
title_short Underweight is independently associated with mortality in post-operative and non-operative patients admitted to the intensive care unit: a retrospective study
title_sort underweight is independently associated with mortality in post operative and non operative patients admitted to the intensive care unit a retrospective study
url http://www.biomedcentral.com/1471-227X/4/3
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