Part 1: The incidence of geriatric trauma is increasing
The analysis of the NTDB showed that the increase in the number of geriatric trauma ranged from 18% to 30% between 2005 and 2015. Meanwhile, the proportion of trauma patients aged less than 65 years declined during the same period (Figure 1a). The death rate of geriatric trauma patients was significantly higher than that of their younger counterparts. Additionally, the results showed that men had a significantly higher mortality rate than women in geriatric trauma patients (Figure 1b). Eighty nine thousand patients with ISS (injury severity score) ≥9 in the DGU® was analyzed. The mean age rose from 39.11 years in 1993 to 51.10 years in 2013, and the proportion of those aged ≥60 years rose from 16.5% to 37.5% between 1993 and 2013 (Figure 1c, 1d). In China, major trauma accounts for more than 60 million visits annually to hospitals, and is responsible for 700 000 to 800 000 deaths per year [18]. Based on the statistics of National Bureau of Statistics of the People’s Republic of China (http://www.stats.gov.cn/), the proportion of the population who aged 65 or above increased from 7.7% to 10.1% between 2005 and 2014 (Figure 1e).
Part 2: Comparison of different scoring tools for the prediction of in-hospital mortality in geriatric trauma patients
The sample included 311 patients aged ≥ 65 years [16, 17], while 59.00% were male. One hundred and sixty-four (52.73%) patients died in the hospital. Table 1 shows the detailed characteristics of included patients. There was no significant difference between the survival and death group, in terms of trauma mechanism, base excess, body mass index, leucocytes, thrombocytes, prothrombin, systolic blood pressure, mean artery pressure, and temperature. Patients in the death group were older than those in the survival group. The survivors of geriatric trauma had higher GCS (Glasgow coma Scale) and hemoglobin level, and lower lactate level than the patients who died. We found the length of ICU stay and length of hospital stay were significantly shorter in the death group compared to the survival group.
Table 1 Characteristics of included patients
|
|
Survival
|
Death
|
P value
|
Number of patient
|
147
|
164
|
|
Trauma mechanism
|
|
|
|
Blunt
|
144(48.30%)
|
154(51.70%)
|
0.07
|
Penetrating
|
3(23.10%)
|
10(76.90%)
|
GCS
|
|
|
|
3-8
|
47(27.30%)
|
125(72.7-%)
|
<0.01
|
9-12
|
22(61.10%)
|
14(38.90%)
|
13-15
|
78(75.70%)
|
25(24.30%)
|
Age
|
74.00 (68.25 to 80.00)
|
78.00(72.00 to 83.00)
|
<0.01
|
Base excess [mEq/L]
|
-2.80 (-5.50 to -0.80)
|
-3.25(-7.80 to -0.55)
|
0.32
|
Body mass index
|
25.95 (22.89 to 28.40)
|
25.90(22.04 to 29.16)
|
0.74
|
Hemoglobin [g/L]
|
11.80 (9.90 to 13.10)
|
10.60(8.10 to 12.20)
|
<0.01
|
Lactate [mmol/L]
|
1.90 (1.15 to 2.80)
|
2.10(1.40 to 3.40)
|
0.03
|
Los of hospital [days]
|
16.50 (9.00 to 25.00)
|
1.50(1.00 to 3.00)
|
<0.01
|
Leucocytes [10^9/L]
|
10.49 (7.33 to 13.96)
|
11.12(6.96 to 14.24)
|
0.86
|
Thrombocytes [10^9/L]
|
190.50(152.00 to 239.50)
|
174.00(132.00 to 230.00)
|
0.07
|
Prothrombin [% normal]
|
80.00 (59.00 to 95.00)
|
74.00(52.00 to 89.25)
|
0.08
|
Systolic pressure mmHg]
|
142.50 (115.00 to 160.000)
|
125.00(110.00 to 158.75)
|
0.09
|
Mean artery pressure [mmHg]
|
100.00 (82.00 to 112.75)
|
92.00(76.50 to 113.50)
|
0.22
|
Temperature
|
35.40(34.50 to 36.20)
|
35.25(34.10 to 36.00)
|
0.31
|
Los of ICU [days]
|
5.00 (2.00 to 12.00)
|
1.00(0.50 to 2.00)
|
<0.01
|
Los of MV [days]
|
1.00(0.00 to 6.25)
|
1.00(0.25 to 2.00)
|
0.04
|
GCS, Glasgow score; Los, length of stay; ICU, Intensive care unit; MV, mechanical ventilation.
The ISS (34.00 vs 24.00, P<0.01), NISS (50.00 vs 27.00, P<0.01), APACHE Ⅱ (23.00 vs 15.00, P<0.01), and SAPS Ⅱ (55.00 vs 34.00, P<0.01) in the death group were significantly higher than that in the survival group. The median TRISS was significantly lower in the death group than that in the survival group (0.51 vs 0.96, P<0.01) (Table 2 and Figure 2).
Table 2 Comparison of different scoring tools between two groups
|
|
Survival
|
Death
|
P value
|
ISS
|
24.00 (14.50 to 29.00)
|
34.00(25.00 to 75.00)
|
<0.01
|
NISS
|
27.00 (22.00 to 38.00)
|
50.00(34.00 to 75.00)
|
<0.01
|
TRISS
|
0.96(0.78 to 0.99)
|
0.51(0.11 to 0.82)
|
<0.01
|
APACHE Ⅱ
|
15.00 (10.00 to 22.00)
|
23.00(19.00 to 29.00)
|
<0.01
|
SPAS Ⅱ
|
34.00 (27.00 to 55.00)
|
55.00(34.75 to 61.00)
|
<0.01
|
SPAS Ⅱ, simplified acute physiology score Ⅱ; APACHE Ⅱ, Acute Physiology and Chronic Health Evaluation Ⅱ; ISS, injury severity score; NISS, new injury severity score; TRISS, Trauma and Injury Severity Score.
The AUCs were calculated to assess the performance of different scoring tools for the prediction of in-hospital mortality in geriatric trauma patients. Table 3 and Figure 3 shows the AUC of the ISS was 0.807, NISS was 0.850, TRISS was 0.828, APACHE Ⅱ was 0.715, and SPAS Ⅱ was 0.725. Table 4 shows the difference between the AUCs of different scoring tools. Compared with APACHE Ⅱ and SAPS Ⅱ, the ISS, NISS, and TRISS appear to be better predictors of in-hospital mortality in elderly trauma patients. Especially the AUCs of NISS and TRISS were significantly higher than that of the APACHE Ⅱ and SPAS Ⅱ (P<0.01).
Table 3 Diagnostic value of different scoring tool in predicting in-hospital mortality
|
|
AUC
|
95% CI of AUC
|
APACHE Ⅱ
|
0.715
|
0.644 to 0.778
|
ISS
|
0.807
|
0.743 to 0.861
|
NISS
|
0.850
|
0.790 to 0.898
|
SPAS Ⅱ
|
0.725
|
0.655 to 0.788
|
TRISS
|
0.828
|
0.766 to 0.880
|
SPAS Ⅱ, simplified acute physiology score Ⅱ; APACHE Ⅱ, Acute Physiology and Chronic Health Evaluation Ⅱ; ISS, injury severity score; NISS, new injury severity score; TRISS, Trauma and Injury Severity Score; AUC, area under the receiver operating characteristic curve.
Table 4 The matrix of AUC comparison between different scoring tool using P value
|
|
SPAS Ⅱ
|
APACHE Ⅱ
|
ISS
|
NISS
|
TRISS
|
SPAS Ⅱ
|
|
0.61
|
0.07
|
<0.01
|
<0.01
|
APACHE Ⅱ
|
0.61
|
|
0.03
|
<0.01
|
<0.01
|
ISS
|
0.07
|
0.03
|
|
0.02
|
0.34
|
NISS
|
<0.01
|
<0.01
|
0.02
|
|
0.37
|
TRISS
|
<0.01
|
<0.01
|
0.34
|
0.37
|
|
SPAS Ⅱ, simplified acute physiology score Ⅱ; APACHE Ⅱ, Acute Physiology and Chronic Health Evaluation Ⅱ; ISS, injury severity score; NISS, new injury severity score; TRISS, Trauma and Injury Severity Score; AUC, area under the receiver operating characteristic curve.