The impact of obesity on Singaporean trauma patients and their venous thromboembolism risk

Background The impact of obesity on trauma outcomes had been equivocal and the majority of these studies were conducted in the Western population. The aim of our study is to evaluate the impact of obesity on morbidity and mortality in Singaporean patients after trauma. Methods A retrospective case control study of trauma patients admitted to a tertiary institution was performed. Patients admitted for both blunt and penetrating trauma who are aged 16 years and above were included. Propensity score matching (PSM) was performed to reduce selection bias. Results A total of 5239 patients were reviewed (obese 648, non-obese 4591). Median age was 76 (IQR 63-83) years. Median BMI was 22.8 kg/m(2) (IQR 20.4-25.2). The overall median ISS was 10 (IQR 9-14). Median ISS was higher in non-obese patients, 10 (IQR 9-14) as compared to obese patients of ISS 9 (IQR 9-13), p = 0.003. Obese patients had more abdominal injuries, n = 27/648 (4.2%) than non-obese n = 114/4591 (2.5%), p = 0.013. Non-obese patients had more head injuries, n = 1698/4591 (37%) as compared to the obese n = 195/648 (30.1%), p = 0.001. In-hospital mortality was comparable in the matched cohort (obese n = 11/645 (1.7%), (non-obese, n = 39/1290 (3.0%), OR 0.56 [0.28-1.09], p = 0.085). ICU admission was shorter for the obese (n = 36/645 (5.6%) versus n = 108/1290 (8.4%), OR 0.65 [0.44-0.96], p = 0.027). Obese patients had higher incidence of venous thromboembolism (n = 16/645 (2.5%) versus n = 12/1290 (0.9%), OR 2.71 [1.27-5.76], p = 0.007). Conclusion Obese trauma patients had fewer head injuries, fewer ICU admissions but comparable mortality rates. Obesity was also associated with higher incidence of venous thromboembolism in the matched cohort.