Participants:
We screened 5264 eligible trauma patients over the study period. A total of 538 patients were identified as adult drivers in road traffic accidents and presented to the ED of MNH within 24hrs of the injury (Fig. 1). The majority of our patients were male (n = 520, 96.7%), young (median age 30, IQR 25–36) and drove motorcycles (83.6%) or cars (11.9%) (Table 1). Nearly two thirds of patients were transferred to our facility from outlying hospitals. The median time between injury and ED arrival was 5.77 hours (IQR 3.76-9.37hs) for those referred from another facility vs 4.2 hours (IQR 1.73–9.73) for those presenting directly to the MNH ED.
Table 1
Descriptive characteristics of patients enrolled
Total patients | 538 |
Median age, years (IQR) | 30 (25–36) |
Gender, female (%) | 17 (3.1%) |
Vehicle driven (%) Motorcycle Car Bus Bajaj | 442 (83.6%) 64 (11.9%) 1 (0.2%) 23 (4.3%) |
Referred from other hospitals Yes No | 351 (65.2%) 187 (34.8%) |
Alcohol Saliva Swab obtained (%) Not obtained (%) Reason: Unable to produce sample Intubated Copious blood in mouth Lack of consent Not documented | 191 (35.5%) 347 (64.5%) 103 (29.7%) 6 (1.7%) 87 (25.1%) 32 (9.2%) 119 (34.3%) |
Urine drug screen obtained (%) Not obtained (%) Reason: No urine sample available Not documented | 362 (67.3%) 176 (32.7%) 52 (29.5%) 124 (70.5%) |
ASSIST completed (%) Not administered (%) Reason: Patient altered Patient refusal Not documented | 417 (77.5%) 121 (22.5%) 9 (7.4%) 101 (83.5%) 11 (9.1%) |
IQR = interquartile range. ASSIST = Alcohol, Smoking and Substance Involvement Screening Test. |
BAC testing was available for 191 patients, or 35.5% of the study population. BAC was not available in 347 (67.3%) because either they were unable to produce a saliva sample (103 patients, 29.7% of those without BAC), due manufacturer recommended test contraindications such as intubation (6 patients, 1.7%) or copious blood in the mouth (87 patients, 25.1%), or due to lack of consent (32 patients, 9.2%). The reason was not documented in 119 patients (34.3%). The majority (176, 92.1%) of patients who had BAC testing had levels < 20 mg/dL. Fourteen patients (7.3%) had BAC levels 20–80 mg/dL, and one patient had a level of 80–300 mg/dL. No patients had BAC levels > 300 mg/dL (Table 2).
Table 2
Blood alcohol content levels by saliva testing
| N = 191, Count (%) |
0–20 mg/dL | 176 (92.1%) |
20–80 mg/dL | 14 (7.3%) |
80–300 mg/dL | 1 (0.5%) |
> 300 mg/dL | 0 (%) |
A urine drug screen (UDS) was available for 362 patients (67.3%), and was not obtained in 176 (23.7%). Of those who did not receive a UDS, 52 patients (29.5%) did not have urine available, and the reason was not documented in 124 patients (70.5%). 68 (18.7%) had a positive result for at least one illicit substance. The most commonly detected illicit substance was tetrahydrocannabinol (THC) (n = 34, 9.4%), the active compound in marijuana, followed by benzodiazepines (n = 28, 7.7%), phencyclidine (PCP) (n = 5, 1.4%), non-methadone opiates (n = 4, 1.1%), methadone (n = 1, 0.3%), barbiturates (n = 3, 0.8%), and cocaine (n = 1, 0.3%).
Table 3
| N = 362 Count (%) |
All Negative | 294 (81.2%) |
At Least One Positive | 68 (18.7%) |
Benzodiazepines | 28 (7.7%) |
Barbiturates | 3 (0.8%) |
Cocaine | 1 (0.3) |
THC | 34 (9.4%) |
Methamphetamines | 0 (0%) |
Opiates | 4 (1.1%) |
PCP | 5 (1.4%) |
Amphetamines | 0 (0%) |
Methadone | 1 (0.3%) |
THC = tetrahydrocannabinol. PCP = phencyclidine |
A total of 177 patients had both a UDS and BAC level completed. Of these, three (1.7%) had both a positive UDS and BAC, all of which were positive for THC and one of which was positive for THC and PCP. Nine patients (5.1%) had a positive BAC and a negative UDS, 23 patients had a positive UDS and a negative BAC (13.9%) and in 142 patients (80.2%) both tests were negative.
The ASSIST tool was completed for 417 patients (77.5%). Of the 121 (22.5%) of patients who did not have a complete ASSIST tool, 9 (7.4%) were altered, 101 (83.5%) refused consent, and the reason was not documented for 11 (9.1%). 29 patients (6.9%) were at high risk for an alcohol use disorder, and 75 patients (18.0%) were at medium risk for an alcohol use disorder. Seventeen (4.1%) patients were at high risk for a tobacco use disorder, while 47(11.3%) were at medium risk for a tobacco use disorder. Only one patient (0.2%) as at high risk for an opiate use disorder, and no patients were at high risk for use disorders of other substances. Thirteen patients (3.1%) were at medium risk for a cannabis use disorder. Few patients were at high risk for use disorders of other substances included sedatives (n = 1, 0.2%), hallucinogens (n = 1, 0.2%), or opiates (n = 2, 0.5%) (Table 4).
Table 4
| Low risk (Score 0–3 for drugs, 0–10 for alcohol) N = 417 Count (%) | Medium risk (Score 4–26 for drugs, score 11–26 for alcohol) N = 417 Count (%) | High risk (Score >/= 27) N = 417 Count (%) |
Tobacco | 353 (84.7%) | 47 (11.3%) | 17 (4.1%) |
Alcohol | 313 (75.1%) | 75 (18.0%) | 29 (6.9%) |
Cannabis | 404 (96.9%) | 13 (3.1%) | 0 (0%) |
Cocaine | 416 (99.8%) | 1 (0.2%) | 0 (0%) |
Amphetamines | 417 (100%) | 0 (0%) | 0 (0%) |
Inhalants | 417 (100%) | 0 (%) | 0 (0%) |
Sedatives | 416 (99.8%) | 1 (0.2%) | 0 (0%) |
Hallucinogens | 416 (99.8%) | 1 (0.2%) | 0 (0%) |
Opioids | 414 (99.3%) | 2 (0.5%) | 1 (0.2%) |
Other drugs | 417 (100%) | 0 (0%) | 0 (0%) |
Among the 29 patients who were at high risk for an alcohol use disorder, 8 (27.6%) were also at high risk for a tobacco use disorder. None were high risk for a use disorder of another substance, however two patients (6.7%) were also at a medium risk for a cannabis use disorder, including one patient (3.4%) who was at medium risk for both cannabis and cocaine use disorder. Among the 75 patients who were at medium risk for an alcohol use disorder, three (4%) were at high risk for a tobacco use disorder, and 35 (46.7%) were at medium risk for a tobacco use disorder. Eleven (14.7%) were at medium risk for a cannabis use disorder. Ten patients (13.3%) were at medium risk for a use disorder of alcohol, tobacco and cannabis use.
Among the fifteen patients who had a positive BAC, one was high risk for an alcohol use disorder (score of 33), and six (46.7%) were medium or high risk for an alcohol use disorder. The sole patient who presented with an BAC level between 80–300 mg/dL had a low risk ASSIST score for alcohol (score of 0, reporting no lifetime alcohol use) (Table 5). Among the seven patients who had a BAC of 20–80 mg/dL, four had ASSIST score of 0 (reporting no lifetime alcohol use).
Table 5
Blood alcohol content (BAC) and ASSIST scores for alcohol
| Low risk (0–10) Count (%) | Medium risk (11–26) Count (%) | High risk (>/= 27) Count (%) |
BAC 0–20 mg/dL (N = 175) | 127 (72.5%) | 36 (20.5%) | 12 (6.9%) |
BAC 20–80 mg/dL (N = 14) | 7 (50%) | 6 (42.9%) | 1 (7.1%) |
BAC 80–300 mg/dL (N = 1) | 1 (100%) | 0 (0%) | 0 (0%) |
BAC > 300 mg/dL (N = 0) | 0 | 0 | 0 |
Among patients had who a UDS that was positive for an illicit substance, only one patient who was positive for methadone had a score indicating high risk for dependence on that substance (score of 34). Six patients who had a positive UDS for THC (17.6%) were at medium risk for a cannabis use disorder (Table 6). The one patient who had a positive UDS for cocaine had an ASSIST score of 0 for cocaine (reporting no prior uses of that substance). All four patients who had a UDS positive for opiates had an ASSIST score of 0 for opiates. One of the five patients (80%) who tested positive for PCP was at medium risk for a use disorder of hallucinogens; the four others had an ASSIST score of 0 for hallucinogens.
Table 6
Positive urine drug screen and ASSIST scores for substance associated domain
| Low risk (0–3) Count (%) | Medium risk (4–26) Count (%) | High risk (>/= 27) Count (%) |
+Benzodiazepines (Sedatives) N = 27 | 27 (100%) | 0 (0%) | 0 (0%) |
+Barbiturates (Sedatives) N = 3 | 3 (100%) | 0 (0%) | 0 (0%) |
+Cocaine (Cocaine) N = 1 | 1 (100%) | 0 (0%) | 0 (0%) |
+THC (Marijuana) N = 34 | 28 (82.3%) | 6 (17.6%) | 0 (0%) |
+Methamphetamine (Amphetamine/Stimulants) N = 0 | 0 (0%) | 0 (0%) | 0 (0%) |
+Opiates (Opiates) N = 4 | 4 (100%) | 0 (0%) | 0 (0%) |
+PCP (Hallucinogens) N = 5 | 4 (80%) | 1 (20%) | 0 (0%) |
+Amphetamine (Amphetamine/Stimulants) N = 0 | 0 (100%) | 0 (100%) | 0 (100%) |
+Methadone (Opiates) N = 1 | 0 (0%) | 0 (0%) | 1 (100%) |
. THC = tetrahydrocannabinol. PCP = phencyclidine |
For screening for alcohol use, relying on objective testing alone would have identified one patient who had driven with a BAC > 80 mg/dL, and 14 others with a BAC > 20 mg/dL; this strategy would have missed 48 patients who were medium to high risk for an alcohol use disorder but who had a BAC of 0 mg/dL. Relying only the ASSIST score would have identified 104 patients who were medium or high risk for an alcohol use disorder by self-report, but would have missed the one patient driving with a BAC > 80 mg/dL, and would have missed 7 patients driving with a BAC > 20 mg/dL.
For screening for other substances, relying on objective testing would have identified 68 patients with a positive UDS, but would have missed 7 patients who were medium risk for cannabis, one patient who was medium risk for cocaine, one patient who was at medium risk for sedatives, and one patient who was at medium risk for opiates. Relying only on the ASSIST score would have identified 19 patients who were at medium to high risk for use of illicit drugs, but would have missed 27 patients who had a positive UDS for benzodiazepines, 3 patients who had a positive UDS for barbiturates, one patient who had a positive UDS for cocaine, four patients who had a positive UDS for opiates, and four patients who had a positive UDS for PCP.