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. 2016 Nov;42(7):1433-1438.
doi: 10.1016/j.burns.2016.03.007. Epub 2016 Sep 1.

The measured effect magnitude of co-morbidities on burn injury mortality

Laquanda Knowlin  1 , Lindsay Stanford  1 , Danier Moore  1 , Bruce Cairns  1 , Anthony Charles  2
Affiliations

The measured effect magnitude of co-morbidities on burn injury mortality

Laquanda Knowlin et al. Burns. 2016 Nov.

Abstract

Introduction: The ability to better prognosticate burn injury outcome is challenging and historically, most center use the Baux or revised Baux score to help prognosticate burn outcome, however, the weighted contribution of comorbidity on burn mortality has traditionally not been accounted for nor adequately studied. We therefore sought to determine the effect of comorbidities, using the Charlson comorbidity index (CCI) on burn mortality.

Methods: The purpose of this study was to determine the effect of comorbidities on burn injury mortality as determined by the LA50 (lethal TBSA burn at which 50% of the cohort will succumb from the burn injury) in a retrospective analysis of patients admitted to a regional burn center from 2002 to 2012. Independent variables analyzed included basic demographics, burn mechanism, presence of inhalation injury, TBSA (total body surface area), length of hospital stay, and pre-existing comorbidities. Bivariate analysis was performed and logistic regression modeling using significant variables was utilized to estimate odds of death.

Results: 7640 patients were included in this study. Overall survival rate was 96%. 40% of our burn cohort had at least one comorbidity. There was a linear increase in the likelihood of death with an increase in CCI. The logistic regression model for mortality outcomes identified four statistically significant variables: age, TBSA, inhalational injury and the presence of comorbidities (OR=1.59 for each 1 point increase in CCI; 95% CI 1.44-1.77). The unadjusted LA50 was 53% for the entire cohort. Partial adjustment multivariate regression controlling for burn mechanism and inhalation injury only, produced a slight reduction in LA50 for the 0-18 and 19-64 age categories to 76% and 48% TBSA, respectively, but a significant decrease occurred in the ≥65 years age group with a reduced LA50 to 20% TBSA (p<0.001). After full adjustment for all significant covariates, including comorbidities, the independent magnitude of effect of comorbidities on the LA50 was evident in the <65 cohort. The full adjustment showed a LA50 decreased to 61% and 43% TBSA, respectively in the 0-18 and >18-65 age groups respectively (p<0.001), however, in the >65 years age cohort there was no change in the LA50.

Conclusion: Preexisting comorbidities have a significant effect on burn injury mortality in all age groups, particularly the younger burn population. The measured effect of comorbidities in the >65 yr age cohort was mitigated by the co-linearity between age and comorbidities. The inclusion of CCI is imperative so as to better prognosticate burn outcome and help guide expectations and resource utilization, particularly in the younger burn cohort.

Keywords: Burn injury; Burn outcome; Charlson comorbidity index; Comorbidity; LA50%TBSA.

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Figures

Figure 1
Figure 1
The predicted probability for death based on Charlson co-morbidity index
Figure 2
Figure 2
Unadjusted (A) and Adjusted (B) LA50 %TBSA for entire burn cohort * Adjusted for Burn Mechanism, Age and Inhalational injury
See this image and copyright information in PMC

References

    1. Forjuoh SN. Burns in low- and middle-income countries: a review of available literature on descriptive epidemiology, risk factors, treatment, and prevention. Burns. 2006;32:529–537. - PubMed
    1. Peck MD, Kruger GE, van der Merwe AE, et al. Burns and fires from non-electric domestic appliances in low and middle income countries Part I. The scope of the problem Burns. 2008;34:303. - PubMed
    1. Mathers C, Boerma T, Fat DM. The Global Burden of Disease: 2004 Update. World Health Organization; Geneva: 2008.
    1. Baux S. Contribution a l’Etude du traitement local des brulures thermigues etendues. Paris: These; 1961.
    1. Zawacki BE, Azen SP, Imbus SH, Chang YT. Multifactorial probit analysis of mortality in burned patients. Ann Surg. 1979;189:1–5. - PMC - PubMed

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