Influence of pre-existing medical condition and predicting value of modified Elixhauser comorbidity index on outcome of burn patients.

Objectives: To evaluate the impact of comorbidity and predicting value of the modified Elixhauser comorbidity index score on the outcome of burn patients.

Methods: A retrospective study was conducted on 5480 patients admitted during 24 h after burn to the National Burn Hospital from 1/1/2016 to 31/12/2018. Demographic data and pre-existing medical conditions were collected. Modified Elixhauser comorbidity index (ECI) score developed by Walravel et al. was calculated for each patient. The score was the weighted sum of comorbid conditions. Outcomes measured included hospitalization, complication and mortality.

Results: Among 5480 patients, 345(6.3%) had at least one pre-existing medical condition. Most common comorbidities were neurological disorder, diabetes, hypertension and psychoses. Pre-existing medical conditions were more common in elderly (25% vs. 4.8%; p < .001) and female (7.5% vs. 5.8%; p < .05). Moreover, significantly larger burn extent, higher rate of inhalation injury (p < .01) and complication (12.8% vs. 6.1%; p < .001), longer time of hospitalization (21.4 vs. 17.1 days; p < .001) were recorded in comorbidity group. It is noted that higher ECI score was remarkably higher in patients who developed complication (.6 vs. .3 respectively, p < .05) and death (.5 vs. .3; p < .05). Multivariate analysis indicated that apart from presence of inhalation injury, increased burn extent, full thickness burn area, ECI score was an independently predicted factor for prolonging the time of staying, for the development of complication and death. Each score of ECI results in increased probability unit of complication to .13 and probability unit of death to .11.

Conclusion: Pre-existing medical conditions lead to more severe and worse outcomes among burn patients. Modified Elixhauser comorbidity index score should be used as a prognosis factor for outcomes of burn patients.