The source population was all emergency surgical admissions to JUSH, from which study units with history of trauma were used and calculated using single population formula, N=Zα/2×P(1-P)/d2 (where P is the proportion of trauma admission from similar studies, Z=1.96 at 95% CI, and margin of error d=0.05), taking proportion of trauma admission (P)=20.9%,7 and sample size of 246 was calculated to have adequate power. Due to small study units, convenient sampling technique was used to incorporate all eligible cases of interest. A total of 241 patient registries were retrieved out of which 30 were excluded due to incomplete documentation, and finally 211 cases were included for analysis. We acknowledge that the power from the calculated sample might not be strong as it was based on uncontrolled previous study.