A total of 9420 cases were received in surgical emergency department of Dilla University Teaching and Referral Hospital from January 2008-June 2019, from which 4390 patients were trauma cases. 376 cases had complete documentation from 384 included samples giving a response rate of 98%.
Socio-demographic characteristics
The mean and SD of ages of study participants was 24.5(±10.3). In this study, the youngest and the oldest trauma victims were 3 years and 66 years old respectively. The majority of victims were in the age range of 20-40 years, 196(52.1%) whereas 29(7.7%) cases were in the age range of greater than 40 years old. The majority of cases experiencing trauma were rural dwellers 225(59.8%) compared to urban dwellers who were 151(40.2%). In this study, patients with low socioeconomic status accounted the majority of trauma incidents compared to middle and high socioeconomic status. More than half of the study participants were single 243(62.2%) whereas there was only one divorced trauma victim. On the other hand, students accounted the majority of trauma incidents 161(42.8%) followed by farmers 80(22.1%), (Table 1)
Table-1: socio-demographic characteristics of patients visiting surgical emergency department, DHURH, 2016-2019, (n=376)
Characteristics
|
Category
|
Number
|
Percent
|
Age
|
≤ 20
|
151
|
40.2
|
20-40
|
196
|
52.1
|
≥40
|
29
|
7.7
|
Gender
|
Male
|
267
|
71
|
Female
|
109
|
29
|
Place of Residence
|
Urban
|
151
|
40.2
|
Rural
|
225
|
59.8
|
Educational status
|
Illiterate
|
76
|
20.2
|
Read and write
|
73
|
19.4
|
Primary school
|
124
|
33
|
Secondary school
|
93
|
24.7
|
College and above
|
10
|
2.7
|
Marital status
|
Single
|
243
|
62.2
|
married
|
137
|
36.4
|
Widowed
|
4
|
1.1
|
Divorced
|
1
|
0.3
|
Occupation
|
Student
|
161
|
42.8
|
Civil servant
|
11
|
2.9
|
Driver
|
35
|
9.3
|
Farmer
|
83
|
22.1
|
Unemployed
|
80
|
21.3
|
Others
|
6
|
1.6
|
Income
|
Low
|
280
|
74.5
|
Middle
|
90
|
23.9
|
High
|
6
|
1.6
|
Living condition
|
Home
|
373
|
99.2
|
Street
|
3
|
0.8
|
Epidemiology of trauma
In this study, the overall prevalence of trauma was 46.6%. Road Traffic Accident was the commonest mechanism of injury 178(47.3) followed by assault 113(30.1%) whereas burn injury was the lowest mechanism of injury 22 (5.9), (Figure 2).
Figure 2 Mechanism of Injury
The commonest types of injury was lower extremity injury 135(35.9%) followed by upper extremity 74(19.7) and Polytrauma 58(15.4) whereas chest trauma was the found to be the lowest types of injury, (Figure 3).
Figure 3 Types of Injury
Outcomes of trauma
In this study, there was 23(6%) death from included samples visiting surgical emergency department. Mortality of cases were more prevalent in 20-40 age groups 13(56.5%) and who are male 12(52.2%). There was more death in rural dwellers 16(69.6%) compared to the one who lives in Urban 7(30.4). The majority of deaths occurred in students 6(20.1%) and who are male 12(52.2) when compared to the other groups. Besides, the mortality of cases was very high in low socioeconomic status when compared to middle and high socioeconomic status, (Table 2)
Table-2: socio-demographic characteristics and outcomes of patients visiting surgical emergency department of Dilla University Teaching and Referral Hospital, 2016-2019, (n = 376)
Variable
|
Category
|
Outcome
|
Number (%)
|
Improved
|
Died
|
Age
|
<20
|
145
|
6
|
151(40.2)
|
20-40
|
183
|
13
|
196(52.1)
|
>40
|
25
|
4
|
29(7.7)
|
Gender
|
Male
|
255
|
12
|
267(71)
|
|
Female
|
98
|
11
|
109(29)
|
Place of residence
|
Urban
|
144
|
7
|
151(40.2)
|
|
Rural
|
209
|
16
|
225(59.8)
|
Educational status
|
Illiterate
|
66
|
10
|
76(20.2)
|
Read and write
|
118
|
5
|
123(32.7)
|
Primary school
|
69
|
4
|
73(19.4)
|
Secondary school
|
90
|
4
|
94(25)
|
College and above
|
10
|
0
|
10(2.7)
|
Marital status
|
Single
|
223
|
13
|
236(62.8)
|
Married
|
125
|
10
|
135(35.9)
|
Widowed
|
4
|
0
|
4(1.1)
|
Divorced
|
1
|
0
|
1(0.3)
|
Occupation
|
Student
|
155
|
6
|
161(42.8)
|
Civil servant
|
10
|
1
|
11(2.9)
|
Driver
|
34
|
1
|
35(9.3)
|
Farmer
|
75
|
8
|
83(22.1)
|
Unemployed
|
73
|
7
|
80(21.3)
|
Others
|
6
|
0
|
6(1.6)
|
Income
|
Low
|
264
|
16
|
280(74.4)
|
Medium
|
87
|
3
|
90(24)
|
High
|
2
|
4
|
6(1.6)
|
Living condition
|
Home
|
351
|
22
|
373(99.2)
|
Street
|
2
|
1
|
3(0.8)
|
Road Traffic Accident was the commonest cause death 12(52.2%) followed by assault 8(34%) and the least was found in burn patients. Polytrauma was responsible for the majority of death 10(43.5%) followed by head injury 9(39.1). The mortality of cases with lower trauma score at admission was very high. The mortality of cases that arrived in health institution after one hour was very high, (Table 3).
Table-3: epidemiology of trauma and outcomes of patients visiting surgical emergency department of Dilla University Teaching and Referral Hospital, 2016-2019, (n = 376)
Variable
|
Category
|
Outcome
|
Number (%)
|
Improved
|
Died
|
Mechanism of injury
|
RTA
|
166
|
12
|
178(47.3)
|
Assault
|
105
|
8
|
113(30.1)
|
Fall
|
58
|
3
|
61(16.2)
|
Burn
|
9
|
0
|
9(2.4)
|
Others
|
15
|
0
|
15(4)
|
Types of injury
|
Head
|
35
|
9
|
44(11.7)
|
Chest
|
21
|
1
|
22(5.9)
|
Abdomen
|
42
|
1
|
43(11.4)
|
Upper extremities
|
74
|
0
|
74(19.7)
|
Lower extremities
|
133
|
2
|
135(35.9)
|
Polytrauma
|
48
|
10
|
58(15.4)
|
Revised trauma score
|
<10
|
10
|
10
|
20(5.3)
|
≥10
|
343
|
13
|
356(94.7)
|
Glasgow Coma scale
|
Mild
|
349
|
14
|
363(96.5)
|
Moderate
|
4
|
2
|
6(1.6)
|
Severe
|
0
|
7
|
7(1.9)
|
Time to arrive institution
|
Immediate(<1hr)
|
162
|
2
|
164(43.6)
|
Within hrs(1-24hrs)
|
190
|
13
|
203(54)
|
Within days(>24hrs)
|
1
|
8
|
9(2.4)
|
Mode of transportation
|
Ambulance
|
27
|
7
|
34(9)
|
Bajaj
|
141
|
6
|
147(39.1)
|
Taxi
|
169
|
8
|
177(47.1)
|
Others
|
16
|
2
|
18(47.8)
|
Operated on
|
Yes
|
10
|
5
|
15(4)
|
No
|
343
|
18
|
361(96)
|
Hospitalization
|
Less than one day
|
1
|
0
|
1(0.3)
|
1- 7days
|
329
|
11
|
340(90.4)
|
>7days
|
23
|
12
|
35(9.3)
|
Determinants of patient mortality after injury
Using ROC curve, we assessed the individual performance of age of respondent, Glasgow coma scale, revised trauma score, time to arrival, systolic blood pressure and length of hospitalization to predict trauma outcome. In assessing the acceptable discrimination for predicting trauma injury outcome both time to arrival and length of hospitalization are above the reference line and the other variable like Glasgow coma scale, revised trauma score and systolic blood pressure are below the reference line. The ROC analysis curve yielded an area under cure (AUC) =0.96, 95% CI: 0.92-1.00 for time to arrival which showed the highest predictive ability and excellent at discrimination of trauma patient mortality. The AUC for the length of hospitalization was 0.59, 95% CI: 0.46-0.72, which is poor at discrimination of patient outcome (figure 4)
Figure 4 the receiver operating characteristic curve of age, GCS, RTS, SBP, time to arrival and hospitalization
Bivariable logistic regression with crude odds ratio on various clinical characteristics in injury patients and potentially confounding factors that affected the relationship between primary predictor variables and a dichotomous categorical outcome (dead or improved) were considered, with a 95% confidence interval and P < 0.05. Patients with associated abdominal injury, lower extremity injury, time to arrival > 24hrs, being admitted for 1-7 days in hospital, revised trauma score <10, decrease GCS and operation had higher odd of mortality on bivariate analysis
Sex, income, age group, type of injury, time to arrival, revised trauma score (RTS), operated on and Glasgow coma scale (GCS) were the variables that had p-value <0.2 and were considered for multiple logistic regression. After adjustment for multiple logistic regression, Mortality after injury is three times more likely in a patient with revised trauma score less than ten, (AOR] =2.5, 95% CI= [1.8, 25.6]). One unit in decreasing GCS was associated with three times [AOR] =0.3, 95% CI= [0.13, 0.5]) higher odds of predicting mortality. Being admitted for 1-7 days in hospital were 90% [AOR] =0.1, 95% CI= [0.01, 0.8] less likely to predict mortality compared with those admitted for >7 days. Being middle income was also another associated factor with less likely to develop hospital mortality than their counterpart. With regard to time to admission, those with time to arrival <1hr and 1-24hr was associated with less likely to have hospital mortality compared with time to arrival >24hr (table 4).
Table-4: bivariate and multivariate output on factors associated with injury outcomes
Variable
|
Category
|
Outcome
|
COR
|
P-value
|
AOR
|
P-value
|
Improved
|
Died
|
Age
|
<20
|
145
|
6
|
0.26(0.70-0.98)
|
0.04
|
1.87(0.09-39)
|
0.68
|
20-40
|
183
|
13
|
0.44(0.13-1.47)
|
0.18
|
0.51(0.25-10)
|
0.66
|
>40
|
25
|
4
|
1
|
|
1
|
|
Gender
|
Male
|
255
|
12
|
0.42(0.18-0.98)
|
0.04
|
0.54(0.08-3.8)
|
0.54
|
|
Female
|
98
|
11
|
1
|
|
1
|
|
Income
|
Low
|
264
|
16
|
0.03(0.01-0.18)
|
<0.001
|
0.09(0.002-3.5)
|
0.2
|
Medium
|
87
|
3
|
0.02(0.002-0.13)
|
<0.001
|
0.003(0-0.4)
|
0.02
|
High
|
2
|
4
|
1
|
|
1
|
|
Time to arrival
|
Immediate(<1hr)
|
162
|
2
|
0.002(0-0.02
|
<0.001
|
0(0-0.011)
|
<0.001
|
|
Within hrs(1-24hrs)
|
190
|
13
|
0.009(0.001-0.07)
|
<0.001
|
0(0-0.016)
|
<0.001
|
|
Within days(>24hrs)
|
1
|
8
|
1
|
|
1
|
|
Types of injury
|
Head
|
35
|
9
|
1.23(0.45-3.35)
|
0.68
|
1(0.09-10.5)
|
0.99
|
Chest
|
21
|
1
|
0.22(0.02-1.9)
|
0.17
|
0.28(0.01-8.7)
|
0.46
|
Abdomen
|
42
|
1
|
0.11(0.01-0.9)
|
0.04
|
0.35(0.02-5)
|
0.44
|
Upper extremities
|
74
|
0
|
-
|
-
|
-
|
-
|
Lower extremities
|
133
|
2
|
0.07(0.02-0.34)
|
0.001
|
0.07(0.002-2)
|
0.12
|
Polytrauma
|
48
|
10
|
1
|
|
1
|
|
Operated on
|
Yes
|
10
|
5
|
9.53(2.0-30.8)
|
0.0002
|
2(0.06-60)
|
0.69
|
No
|
343
|
18
|
1
|
|
1
|
|
Hospitalization
|
Less than one day
|
1
|
0
|
-
|
-
|
-
|
-
|
1-7days
|
329
|
11
|
0.06(0.03-0.16)
|
<0.0001
|
0.1(0.01-0.8)
|
0.038
|
>7days
|
23
|
12
|
1
|
|
1
|
|
RTS
|
<10
|
10
|
10
|
26.4(9.35-74.41)
|
<0.0001
|
2.5 (1.8-25.6)
|
0.04
|
|
≥10
|
343
|
13
|
1
|
|
1
|
|
GSC Median(IQR)
|
15(0)
|
0.45(0.34-0.58
|
<0.0001
|
0.3(0.13-0.5)
|
0.001
|
COR: Crude Odd Ratio, AOR: Adjusted Odd Ratio, GCS: Glasgow Coma Scale, RTS: Revised Trauma Score