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Alcohol use, driving records, and crash culpability among injured motorcycle drivers
Anal. and Preu. Vol. 25, No. 6, pp. 711-716, 1993 Printed in the U.S.A.
0001-4575/93$6.00 t .OO 0 1993Pergamon Press Ltd.
Accid.
ALCOHOL USE, DRIVING RECORDS, AND CRASH CULPABILITY AMONG INJURED MOTORCYCLE DRIVERS* CARL A. SODERSTROM,~PATRICIAC. DISCHINGER,~SHIU MAN Ho,~ and MARGARET T. SODERSTROM~T+ ‘Department of Surgery, Shock Trauma Center, 3Center for living, Maryland Institute for Emergency Medical Services Systems, Baltimore, MD 21201-1595, U.S.A.; ‘National Study Center for Trauma and Emergency Medical Systems, Baltimore, MD 21201-1595, U.S.A. (Receiued 25 September 1991; in revised form 22 February 1993)
Abs~ct-Alcohol use, driving records, crash culpability, and crash conviction rates for 165 injured motorcycle drivers (MTCDs) were studied. Of the 165 MTCDs, 53.3% tested positive for alcohol (BAC+). Culpability determinations (n = 150) revealed that 83% of BAC+ and 46% of BAC- MTCDs caused their crashes (p < 0.001). Driving records (n = 145) revealed the following prevalence of one or more convictions for BAC+ and BAC- MTCDs: impaired driving (2% vs. 7%, p < 0.001); speeding (74% vs. 58%, p < 0.05); and reckless driving (68% vs. 44%, p < 0.002). Of the surviving culpable impaired MCTDs (n = 48), 16.7% received crash-related convictions, 12.5% received ~cohol-related convictions. The reasons for the low conviction rates are probably multifactoral.
cated (DWI), 7.7% had a prior license revocation or suspension, and 3 1.1% had a prior moving violation (NHTSA 1989). In contrast, among fatally injured drivers with BAG of 100 to 190 mgldl, the prior conviction rates for DWI, revoked/suspended license, and moving violations were five times higher (10.6%), three times higher (20.3%), and one-andone-half times higher (47.2%), respectively. Among those with BACs 2 200, the prior DWI conviction rates (17.6%) and license revo~ation/suspension rates (24.6%) were still higher. Estimates for the probability of being arrested for drunken driving per episode of driving while impaired vary from a high of 1 in 50 to a low of 1 in 2,000 (Macdonald and Pederson 1988; Miller, Whitney, and Washousky 1986). Little is known about preinjury driving records, crash culpability, and crash conviction rates of hospitalized drivers relative to alcohol use. The few published reports that have addressed such issues have predominantly involved injured automobile drivers (Maull, Kinning, and Hickman 1984; Cotquitt, Fielding, and Cronan 1987; Barillo et al. 1990; Soderstrom et al., 1990). In 1981, Terhune and Fell studied the role of alcohol in crash causation among 497 drivers treated in an emergency department. They found that 74% of legally intoxicated drivers were culpable (p < 0.001). The first culpability study of patients admitted
INTRODUCTION
The etiologic link between alcohol use and the causation of both fatal and nonfatal vehicular crashes is well established (Council on Scientific Affairs 1986). Alcohol use was a factor in 53% of the over 300,000 traffic-related deaths occurring between 1982 and 1988 (NHTSA 1989). Among drivers involved in fatal crashes during 1987 and 1988, an estimated 33.3% of passenger car drivers and 50.6% of motorcycle drivers had consumed alcohol prior to crashing. In driver groups, approximately three-quarters had a blood alcohol concentration (BAC) 2 100 mg/dl. Most vehicular crashes do not involve fatalities. According to the National Accident Sampling System (NASS) report of 1986 (NHTSA 1988), there were 8.2 million passenger car crashes and 188,000 motorcycle crashes resulting in the hospitalization of 242,000 car occupants and 43,000 motorcycle riders. An estimated 6% of the passenger car drivers involved in 1986 crashes used alcohol prior to crashing compared to 12% of motorcycle drivers. Among drivers who were fatally injured in 1988 and had no detectable blood alcohol (BAC -), 2.1% had a previous conviction for driving while intoxi*Presentedat the 34th Annual Meeting of the Association for the Advancement of Automotive Medicine, October 5-7, 1991, Toronto, Canada. ?Margaret T. Soderstrom is presently with the Johns Hopkins School of Nursing Baltimore, MD, U.S.A. 711
712
C. A.
SODERSTROM
for treatment, by Maul1 and associates (1984), involved 56 intoxicated drivers (BAC L 150 mg/dl; mean, 240 mgidl) treated in Richmond, Virginia. In all but one of the 52 (98.1%) instances in which crash culpability was assessed, the police considered the drunk drivers culpable of causing the crashes in which they were injured. Only 19 (33.9%) of the 56 drunk drivers received a crash conviction: not one was for driving under the influence (DUB of alcohol. Sixteen percent of the drivers had received a prior DUI conviction, 28.6% had one or more reckless driving convictions, and 35.7% had a previous license suspension or revocation. A subsequent study described 84 drunk injured drivers (BAC I> 106 mgldl; median 219 mgidl) in Connecticut (Colquitt et al. 1987). None of the 59 with complete records received an alcohol-related driving conviction (three were charged with DUD. Crash culpability and preinjury driving records were not addressed. In contrast to the aforementioned reports, Barillo and associates (1990) reported that 4 1% of surviving injured drunk drivers admitted to a Pennsylvania trauma center were arrested for drunk driving, and 98.4% of them received a conviction. Preinjury driving records and crash culpability were not studied. The most comprehensive study of both pre- and postcrash driving records, crash culpability assessment, and convictions of injured drivers involved drivers admitted to a trauma center in Baltimore (Soderstrom et al. 1990). In that study of 150 selected injured car drivers (who survived, were discharged to home, and had moderate injury), the following were noted: (i) among 58 impaired drivers (BAC 2 80 mgldl; mean, I81 mgidl), six (10.3%) received an alcohol-related conviction; (ii) in the 140 crashes in which crash culpability could be assessed, 64.7% of unimpaired drivers (94.6% BAC = 0) were considered culpable compared with 92.7% of impaired drivers (p < 0.001); (iii) although preinjury conviction rates for DWI/DUI, speeding, and reckless driving were significantly higher for impaired drivers, in the postinjury period (2-3 years), the only difference between impaired and unimpaired drivers was a higher alcohol-related conviction rate for the impaired. Littfe is known about injured motorcycle drivers’ alcohol use and crashes. Therefore, we have studied the driving records, crash culpability, and crash convictions of injured hospitalized motorcycle drivers and assessed their use of alcohol. Our methods and findings are presented in this report.
etal.
MATERIALS
AND METHODS
In Maryland, I 1 trauma centers are components of the state’s comprehensive system of emergency medical care, the Maryland Institute for Emergency Medical Services Systems (MIEMSS) (Ramzy 1988). The clinical hub of MIEMSS is the Shock Trauma Center in Baltimore. All injured motorcyclists admitted for treatment to Maryland trauma centers between July 1987 and June 1988 were eligible for this study, which was part of a prospective study of all police-reported motorcycle crashes in Maryland (Shankar et al. 1990). To comply with the Maryland Automated Accident Reporting System (MAARS) (Maryland State Police 1982), state police officers must file a Motor Vehicle Accident Report for any crash in which injury occurs. The reports contain detailed information about crash scenarios, including the number and types of vehicles involved, vehicle condition, lighting and weather conditions, and roadway features and conditions. The reports include both a narrative and diagram description of the crash. Issued citations are recorded. The officer offers an opinion on the report as to primary and secondary driver-related causes of the crash and designates which factor is associated with particular vehicles in the crash. There is a checklist for driver condition, including the items “apparently normal” and “had been drinking.” For this study, Motor Vehicle Accident Reports were obtained from the Maryland State Police. Assessments took into account the above-mentioned information contained in the reports. As previously described (Soderstrom et al. 1990), driver culpability was scored using the five-point “culpability scale” advocated by Terhune (1982). Scores of f and 5 are definitive for culpability assessment: “culpable” (I) indicates that “the subject vehicle was the first to create the dangerous situation” and “neither culpable nor contributory” (5) indicates that the “driver had no responsibility for the accident.” Intermediate scores (2,3,4) are not definitive. Culpability assessments were made by the investigators (CS, PD, MS), who were blinded to BAC results. Driving records from the Maryland Motor Vehicle Administration were reviewed. Violations were grouped into four categories: (i) speeding, (ii) reckless driving (e.g. improper passing, following too closely, failure to yield), (iii) impaired driving (e.g. DUI, DWI, refusal to take a chemical test), and (iv) major license violations (e.g. no license, driving with a suspended or revoked license). Data were analyzed using chi-square tests. To
Crash culpability among injured motorcycle drivers
Table 1. Demographics of injured drivers tested for alcohol compared with all drivers treated BAC obtained (n = 165) Age* Mean <21 yr 21-34 yr 235 yr Mean ISS Died
28.0 yr 16.3% 62.4% 19.4% 15.4 9.6%
Table 3. Single vs. multiple vehicle crashes and alcohol use (N = 165) Single
All drivers (n = 203) 27.7 yri 16.7% 61.5% 20.2% 14.3t 12.6t
*Age not known in three in both groups. tNo significant difference.
713
BAC BAC +
Multiple
No.
%
No.
%
23 47
32.9 67.1
54 41
56.8 43.2
the charge of DWI. Hence, 78 (47.2%) of the drivers in this study were legally impaired. Alcohol use and age
protect patient confidentiality, access to the data base was limited to investigators, and records and reports were kept under lock and key. RESULTS During the study period, 203 motorcycle drivers were admitted to Maryland trauma centers. (More than half [52.7%] were treated at the Shock Trauma Center in Baltimore.) Two hundred of them were men (98.5%). Blood alcohol levels were determined on 165 (81.3%) of the drivers. In Table 1, demographics of drivers in whom a BAC was obtained and of all of the injured drivers are compared. MAARS reports were available foi- all 165 drivers tested for alcohol, and driving records were available for 145 of the 165 drivers tested for alcohol. Those two groups are the focus of the remainder of this report. Alcohol use
Eighty-eight (53.3%) of the drivers tested positive for alcohol use (BAC+) (mean BAC, 144 mg/dl; range, lo-370 mg/dl) (Table 2). For those with a BAC 2 100 mg/dl, the mean was 172 mg/dl. Seventeen (10.3%) had a BAC 2 200 mg/dl. In Maryland, at the time of the study, a BAC of 70-99 mg/dl was consistent with the charge of DUI, and a BAC 2 100 mg/dl was consistent with
The age of 162 drivers was known. Of the 27 drivers under the legal drinking age of 21 years, nine (31.3%) tested positive for alcohol and six (66.7%) of them had a BAC L 100 mg/dl. Of the older drivers, 57.8% were BAC+; of these, 75.6% had a BAC 2 100 mg/dl. Single versus multiple vehicle crashes alcohol use
and
The 42.7% rate of alcohol use among the 96 drivers in multiple vehicle crashes was significantly lower (p < 0.002) than the 68.1% rate among the 69 drivers in single vehicle crashes (Table 3). Culpability
In 150 (90.9%) of the 165 crashes, a definitive culpability score of 1 (culpable) or 5 (neither culpable nor contributory) was determined (Table 4). Of the 70 BAC - drivers, 45.7% were considered culpable of causing the crashes in which they were injured, compared with 67 (82.7%) of the BAC+ drivers (p < 0.001). Among the 60 drivers with a BAC 2 100 mg/dl, 86.7% were considered culpable. All but two of the 41 drivers with BACs 2 150 mg/dl were culpable. Sixty-one (93.8%) of the 65 drivers in single vehicle crashes were considered culpable of causing their crashes. (Defective road conditions, an animal impact [deer], and equipment failure were factors in the other four crashes.) In those crashes, driver culpability was 90.0% among BAC- drivers and
Table 2. BACs of 165 injured motorcycle drivers admitted to Maryland trauma centers
Table 4. Driver culpability and BAC level BAC (mg/dl)
BAC (mg/dl)
Number
%
0
77 10 13 23 42
46.7 6.1 7.9 13.9 25.5
l-69 70-99 100-149 z150
0
l-69
(45?%)
(661j74)
(81.98%)
(867;%)
(54Y%)
(33?3%)
(l&2%)
(13.!%)
70-99
2 100
Culpable Not culpable
714
Table
C. A. SODERSTROM
5. Motorcycle
driver culpability and multiple vehicle crashes
BAC:
BAC-
Single vehicle Culpable Not culpable Multi-vehicle Culpable Not culpable
Single
vs.
No.
%
No.
%
18 2
90.0 10.0
43 2
95.6 4.4
14 36
28.0 72.0
24 I1
68.6 31.4
records
The driving records were complete Maryland histories. There were no significant differences in the age group distributions between the BAC + and BAC - drivers. Hence, driving exposure rates were comparable for both groups of drivers. For each category of violations, a greater percentage of BAC + drivers had preinjury convictions compared to BAC - drivers (Table 6). The differences were highly significant for alcohol/drug and reckless driving convictions. The mean number of impaired driving convictions was over two times higher among BAC + drivers compared to BAC drivers, being 2.8 and 1.2, respectively. Only one of the five BAC - drivers had more than one conviction (two) for such violations; 12 of the 22 BAC + drivers had two or more (two had five each, three had three
6. Preinjury
driving
violations admission Drivers
Speeding (Mean) Reckless (Mean) Alcohol/drug (Mean) Suspended/revoked license (Mean) *NS
= not significant.
7. Crash-related
convictions of drivers and BAC BACs
38 (44.7%) of the 85 drivers involved in multiple vehicle crashes were culpable of their crashes. In those crashes, 28.0% of BAC - drivers were culpable compared to 68.6% of BAC + drivers (p < 0.002).
Table
Table
BAC +
95.6% among BAC + drivers (Table 5). In contrast,
Driving
etal.
and
alcohol
status
on
with violations
BAC (n = 69)
BAC+ (n = 76)
40 (58.0%) (3.3) 30 (43.5%) (2.3) 5 (7.2%) (1.2) 5 (7.2%) (1.4)
56 (73.7%) (3.6) 52 (68.4%) (3.1)
0.05
0.002
(28?t%, (2.8)
0.001
(141:%) (1.4)
NS*
drivers
motorcycle
(mg/dl)
DUI
DWI
BAC (N = 61)* (n = 3)
l-69 (N = 8) (n = 0)
70-99 (N = 10) (n = 2)
PI00 (N = 51) (n = 8)
2 2 0 I$
0 0 0 0
I 0 2t 0
0 4 5
Speeding Reckless DWIiDUIiRef Suspended/ revoked license
I
*N = number of drivers; n = with convictions. t 1 with DUI also received a manslaughter conviction. $Had no license to drive. Ref = refused to submit to chemical test.
each, two had four each, one had six, and another had seven prior to injury). Among the BAC + drivers, five had sustained a total of seven preinjury convictions for fleeing from the police (five) or leaving the scene of a crash (two), compared to one BAC - driver who received a prior conviction for leaving the scene of a crash. Crash
convictions
Of the 145 drivers for whom driving records were available, 130 survived. Crash-related convictions for those drivers are presented in Table 7. Three (4.3%) of the unimpaired drivers (BAC = 0 or < 70 mg/dl) received a total of five crash-related convictions. Ten (16.4%) of the BAC + drivers with illegal BACs received a total of 14 crash-related convictions; seven (11.5%) of these drivers received an alcohol-related conviction. Minor convictions (e.g. not carrying a license) may have been issued but are not listed in Table 7. Convictions
P
of injured
injured
and culpability
Of the 130 surviving drivers with complete driving records, 2 (7.1%) of the 28 unimpaired drivers (BAC = 0, < 70 mg/dl) who were deemed culpable of their crashes received a conviction. Of the 48 impaired culpable drivers (BAC 2 70 mgidl), eight (16.7%) received convictions, six (12.5%) of which were alcohol-related. Police assessment of alcohol crash-related convictions
use, culpability,
and
The police offered an opinion concerning the condition of 44 drivers with a BAC 2 70 mg/dl. On 22 (50.0%) occasions, they indicated that the driver
Crash
culpability
among
“had been drinking.” Among 11 drivers with BACs of 70-99 mg/dl, 5 (45.5%) were assessed to have used alcohol, while among 14 with BACs of loo-149 mg/dl the police assessed that 4 (28.6%) “had been drinking.” Among the 19 drivers with high BACs (2 150 mg/dl), 13 (63.2%) were assessed to have been drinking. Of the 18 drivers who “had been drinking,” and were culpable of their crashes, six (33.3%) received alcohol-related crash convictions. DISCUSSION In this study, the largest of alcohol use among injured motorcycle drivers admitted to hospitals for 53.3% tested positive for alcohol treatment, (BAC+); of those, 88.6% were legally impaired (BAC ~70 mg/dl) and 73.9% had BACs zz 100 mg/dl. The results are similar to the findings of a study of 70 injured motorcycle drivers treated at the MIEMSS Shock Trauma Center two years earlier, 50% of whom were BAC+ and 75% of whom were estimated to have BACs 2 100 mg/dl (Soderstrom et al. 1988). The overall BAC + results in both studies are higher than those from a study of 97 injured cyclists treated between 1975 and 1977 at the Center: 29.9% were BAC + , 72.4% of whom had BACs 2 100 mg/dl (Soderstrom et al. 1979). The figures in the current study are similar to data for 1987 and 1988 from the Fatal Accident Reporting System of fatally injured motorcyclists, of whom 49.4% were BAC + ; 75.5% of that group had a BAC 2 100 mg/dl (NHSTA 1989). The overall 53.3% BAC + rate of this study among injured, hospitalized cyclists is higher than the 32.4% rate for 71 riders (55 drivers) reported by Bried, Cordasco, and Volz (1987) and the 47.1% rate for 51 drivers reported by McLellan and associates (1990). Finally, Luna and colleagues (1984) reported a 38.0% intoxication rate (BAC 2 100 mg/dl) among 92 injured cyclists admitted to a trauma center and tested for alcohol. An additional 47 cyclists were not tested. In the late 197Os, Hurt and colleagues (1981) conducted an extensive study of 900 motorcycle crashes in California. Prospectively, they performed in-depth crash investigations. The current study was limited to a retrospective “in-house” review of police reports. Although the current study lacks the sophistication of the investigation by Hurt et al., the results are similar. The Maryland study showed that motorcyclists involved in single-vehicle crashes were culpable over 90% of the time (compared with two-thirds of cases in the DOT study). Fewer than half of the motorcyclists involved in crashes with another vehicle were deemed culpable in the current study (compared with one-third in the DOT study).
injured
motorcycle
drivers
71.5
Alcohol’s causative role in motorcycle crashes is apparent from the culpability assessment results. Not only were the BAC + drivers found to be culpable at a higher rate compared with BAC- drivers (82.7% vs. 45.7% [p < O.OOl])but also an association between culpability and increasing alcohol level was noted. The alcohol/culpability link was most evident in the finding that more than twice as many BAC + (68.6%) as BAC - (28.6%) drivers (p < 0.002) were deemed culpable in multiple vehicle crashes. The overall alcohol/culpability results of the aforementioned studies of Maul1 and colleagues (1984) and Soderstrom and associates (1990) involving injured automobile drivers are consistent with Baker and Fisher’s (1977) report of fatally injured Maryland motorcycle drivers. The significantly higher rate of preinjury alcohol-related, speeding, and reckless driving convictions noted in this study parallels observations noted among injured automobile drivers treated at the Shock Trauma Center (Soderstrom et al. 1990) and those reported by Maul1 and colleagues (1984). The results of the three studies strongly suggest that previous alcohol-related convictions did not deter the injured from continuing to drive in an impaired state. Further, one should consider that convictions for drunk driving represent only about half of drunk driving arrest episodes (Soderstrom et al. 1990; Maul1 et al. 1984). The 16.4% conviction rate for any crash-related violation for the impaired injured motorcycle drivers in the current study is almost three times less than the 34.5% rate for impaired injured automobile drivers reported previously from the Shock TraumaCenter (Soderstrom et al. 1990). The conviction rate of 11.5% for alcohol-related violations in the current study is comparable to the 10.3% rate in the automobile driver study. The conviction rates in these two MIEMSS Shock Trauma Center studies represent a substantial improvement over the zero conviction rates of injured intoxicated automobile drivers reported by Maul1 and colleagues (1984) and Colquitt and associates (1987). The results of all four studies are eclipsed by the 40.6% alcohol-related conviction rate of injured drivers treated in a Pennsylvania trauma center (Barillo et al. 1990). Maul1 and his colleagues (1984) summarized well the legal, administrative, and psychological factors (including empathy for the injured patient) that present obstacles to the prosecution of impaired injured drivers admitted for treatment. In addition, one must consider the extent of the patient’s injuries and their clinical management (including rehabilitation) on the prosecution process. As noted, the mean
ISS for the study group was 15.4 and the fatality rate was 10%. That degree of injury may have precluded prosecution and trial in a timely fashion for many of the surviving patients, a factor that was not studied. Barillo and colleagues (1990) emphasized the need for such drivers to be identified by the police after the crash. In the present study, among the 33 drivers with BACs 2 100 mg/dl, in which driver condition was assessed, the police concluded that only 51.5% “had been drinking.” In the previous study from the Shock Trauma Center (Soderstrom et al. 1990) the police did not ascertain drinking in 29.3% of impaired injured drivers. Problems of police identification of alcohol use among both fatally (Baker and Fisher 1977) and nonfatally injured drivers (Maul1 et al. 1984) have been documented before. Identification of intoxicated motorcycle drivers is important for both legal (prosecution) and clinical (patient management) reasons. As noted previously, a BAC is routinely obtained at the MIEMSS Shock Trauma Center for patient management. Assessment of patients with elevated BACs (2 70 mg/dl) by the center’s substance abuse counselor for alcoholism and psychoactive substance use disorders is a standard of clinical practice (Soderstrom and Cowley 1987). To reduce morbidity and mortality from drunk driving, the authors advocate systems in which legal and clinical protocols are designed to complement each other. Acknowledgements-Portions of this study were supported by Grant DTNH22-87-Z-07490 from the U.S. Department of Transportation, National Highway Traffic Safety Administration. The
final report (DOT HS 807 612)for fulfillment of grant requirements is available from the National Technical Information Service. The authors thank the Maryland State Police for supplying crash reports and the driver records section of the Maryland Motor Vehicle Administration for providing driver records. We also thank John New for management of the Maryland Trauma Registry and Linda Kessehing for editorial assistance.
REFERENCES Baker, S. P.; Fisher, R. S. Alcohol and motorcycle fatalities. Am. J. Public Health 67:246-249; 1977. Barillo, D.; Earnest, T.; Rhodes, M.; Fina, R. Legal outcomes of intoxicated drivers involved in motor vehicle collisions. 34th Proceedings Association for the Advancement of Automotive Medicine 34:83-95; 1990. Bried, J. M.; Cordasco, F. A.; Volz, R. G. Medical and
economic parameters of motorcycle-induced trauma. Clin. Orthop. 223:252-256; 1987. Coiquitt, M.; Fielding, L. P.; Cronan, J. F. Drunk drivers and social injury. N. Engl. J. Med. 317:1262-1266; 1987. Council on Scientific Affairs, American Medical Association. Alcohol and the driver. J.A.M.A. 255:522-527; 1986.
Hurt, H. H., Jr.; Ouellet, J. V.; Thorn, D. R. Motorcycle accident cause factors and identification of countermeasures. Volume I: Technical report. Publication DOT HS-805 862. Washington, DC: National Highway Traffic Safety Administration, U.S. Department of Transportation; 198 1. Luna, G. K.; Maier, R. V.; Sowder, L.; et al. The influence of ethanol intoxication on outcome of injured motorcyclists. J. Trauma 24:695-700; 1984. Macdonald, S.; Pederson, L. L. Occurrence and patterns of driving behaviour for alcoholics in treatment. Drug Alcohol Depend. 22:15-25; 1988. Maryland State Police. Maryland Automated Accident Reporting System: MAARS Form Preparation Manual. Pikesville, MD: MSP Headquarters; September 21, 1982. Maull, K. I.; Kinning, L. S.; Hickman, J. K. Culpability and accountability of hospitalized injured alcohol-impaired drivers. J.A.M.A. 252:1880-1883; 1984. McLellan, B. A.; Vingilis, E.; Liban, C. B.; et al. Blood alcohol testing of motor vehicle crash admissions at a regional trauma center. J. Trauma 30:418-421; 1990. Miller, B. A.; Whitney, R.; Washousky, R. Alcoholism diagnosis for convicted drinking drivers referred for alcoholism evaluation. Alcohol. Clin. Exp. Res. 10:651-656; 1986. NHTSA (National Highway Traffic Safety Administration.) Fatal Accident Reporting System 1988: A review of information on fatal traffic crashes in the United States in 1988. DOT HS 807 507. Washington, DC: U.S. Department of Transportation; December 1989. NHTSA. National Accident Sampling System-1986: A report on traffic crashes and injuries in the United States. DOT HS 807 296. Washington, DC: U.S. Department of Transportation; July 1988. Ramzy, A. I. The Maryland emergency medical services system: An update. Md. Med. J. 37:517-520; 1988. Shankar, B. S.; Dischinger, P. C.; Ramzy, A. I.; SoderStrom, C. A.; Clark, C. C. Helmet use, patterns of injury and medical outcome among motorcycle drivers in Maryland. Proceedings of the Association for the Advancement of Automotive Medicine. Des Plaines, IL: AAAM; 1990: 13-34. Soderstrom, C. A.; Birschbach, J.; Dischinger, P. C. Injured drivers and alcohol use: Culpability, convictions, pre- and post-crash driving history. J. Trauma 30:1208-1214; 1990. Soderstrom, C. A.; Cowley, R A. A national alcohol and trauma center survey: Missed opportunities, failures of responsibility. Arch. Surg. 122: 1067-1071; 1987. Soderstrom, C. A.; DuPriest, R. W., Jr.; Benner, C.; et al. Alcohol and roadway trauma: Problems of diagnosis and management. Am. Surg. 45:129-136; 1979. Soderstrom, C. A.; Trifillis, A. L.; Shankar, B. S.; Clark, W. E.; Cowley, R A. Marijuana and alcohol use among 1023 trauma patients. Arch. Surg. 123:733-737; 1988. Terhune, K. W. An evaluation of crash culpability to assess alcohol and drug impairment effects. Proceedings of the American Association for Automotive Medicine 26:329-348, 1982. Terhune, K. W.; Fell, J. C. The role of alcohol, marijuana, and other drugs in the accidents of drivers. NHTSA Technical Report DOT-HS-806- 18 1. Twenty-fifth Proceedings of the American Association of Automotive Medicine, October l-3, 1981.
0001-4575/93$6.00 t .OO 0 1993Pergamon Press Ltd.
Accid.
ALCOHOL USE, DRIVING RECORDS, AND CRASH CULPABILITY AMONG INJURED MOTORCYCLE DRIVERS* CARL A. SODERSTROM,~PATRICIAC. DISCHINGER,~SHIU MAN Ho,~ and MARGARET T. SODERSTROM~T+ ‘Department of Surgery, Shock Trauma Center, 3Center for living, Maryland Institute for Emergency Medical Services Systems, Baltimore, MD 21201-1595, U.S.A.; ‘National Study Center for Trauma and Emergency Medical Systems, Baltimore, MD 21201-1595, U.S.A. (Receiued 25 September 1991; in revised form 22 February 1993)
Abs~ct-Alcohol use, driving records, crash culpability, and crash conviction rates for 165 injured motorcycle drivers (MTCDs) were studied. Of the 165 MTCDs, 53.3% tested positive for alcohol (BAC+). Culpability determinations (n = 150) revealed that 83% of BAC+ and 46% of BAC- MTCDs caused their crashes (p < 0.001). Driving records (n = 145) revealed the following prevalence of one or more convictions for BAC+ and BAC- MTCDs: impaired driving (2% vs. 7%, p < 0.001); speeding (74% vs. 58%, p < 0.05); and reckless driving (68% vs. 44%, p < 0.002). Of the surviving culpable impaired MCTDs (n = 48), 16.7% received crash-related convictions, 12.5% received ~cohol-related convictions. The reasons for the low conviction rates are probably multifactoral.
cated (DWI), 7.7% had a prior license revocation or suspension, and 3 1.1% had a prior moving violation (NHTSA 1989). In contrast, among fatally injured drivers with BAG of 100 to 190 mgldl, the prior conviction rates for DWI, revoked/suspended license, and moving violations were five times higher (10.6%), three times higher (20.3%), and one-andone-half times higher (47.2%), respectively. Among those with BACs 2 200, the prior DWI conviction rates (17.6%) and license revo~ation/suspension rates (24.6%) were still higher. Estimates for the probability of being arrested for drunken driving per episode of driving while impaired vary from a high of 1 in 50 to a low of 1 in 2,000 (Macdonald and Pederson 1988; Miller, Whitney, and Washousky 1986). Little is known about preinjury driving records, crash culpability, and crash conviction rates of hospitalized drivers relative to alcohol use. The few published reports that have addressed such issues have predominantly involved injured automobile drivers (Maull, Kinning, and Hickman 1984; Cotquitt, Fielding, and Cronan 1987; Barillo et al. 1990; Soderstrom et al., 1990). In 1981, Terhune and Fell studied the role of alcohol in crash causation among 497 drivers treated in an emergency department. They found that 74% of legally intoxicated drivers were culpable (p < 0.001). The first culpability study of patients admitted
INTRODUCTION
The etiologic link between alcohol use and the causation of both fatal and nonfatal vehicular crashes is well established (Council on Scientific Affairs 1986). Alcohol use was a factor in 53% of the over 300,000 traffic-related deaths occurring between 1982 and 1988 (NHTSA 1989). Among drivers involved in fatal crashes during 1987 and 1988, an estimated 33.3% of passenger car drivers and 50.6% of motorcycle drivers had consumed alcohol prior to crashing. In driver groups, approximately three-quarters had a blood alcohol concentration (BAC) 2 100 mg/dl. Most vehicular crashes do not involve fatalities. According to the National Accident Sampling System (NASS) report of 1986 (NHTSA 1988), there were 8.2 million passenger car crashes and 188,000 motorcycle crashes resulting in the hospitalization of 242,000 car occupants and 43,000 motorcycle riders. An estimated 6% of the passenger car drivers involved in 1986 crashes used alcohol prior to crashing compared to 12% of motorcycle drivers. Among drivers who were fatally injured in 1988 and had no detectable blood alcohol (BAC -), 2.1% had a previous conviction for driving while intoxi*Presentedat the 34th Annual Meeting of the Association for the Advancement of Automotive Medicine, October 5-7, 1991, Toronto, Canada. ?Margaret T. Soderstrom is presently with the Johns Hopkins School of Nursing Baltimore, MD, U.S.A. 711
712
C. A.
SODERSTROM
for treatment, by Maul1 and associates (1984), involved 56 intoxicated drivers (BAC L 150 mg/dl; mean, 240 mgidl) treated in Richmond, Virginia. In all but one of the 52 (98.1%) instances in which crash culpability was assessed, the police considered the drunk drivers culpable of causing the crashes in which they were injured. Only 19 (33.9%) of the 56 drunk drivers received a crash conviction: not one was for driving under the influence (DUB of alcohol. Sixteen percent of the drivers had received a prior DUI conviction, 28.6% had one or more reckless driving convictions, and 35.7% had a previous license suspension or revocation. A subsequent study described 84 drunk injured drivers (BAC I> 106 mgldl; median 219 mgidl) in Connecticut (Colquitt et al. 1987). None of the 59 with complete records received an alcohol-related driving conviction (three were charged with DUD. Crash culpability and preinjury driving records were not addressed. In contrast to the aforementioned reports, Barillo and associates (1990) reported that 4 1% of surviving injured drunk drivers admitted to a Pennsylvania trauma center were arrested for drunk driving, and 98.4% of them received a conviction. Preinjury driving records and crash culpability were not studied. The most comprehensive study of both pre- and postcrash driving records, crash culpability assessment, and convictions of injured drivers involved drivers admitted to a trauma center in Baltimore (Soderstrom et al. 1990). In that study of 150 selected injured car drivers (who survived, were discharged to home, and had moderate injury), the following were noted: (i) among 58 impaired drivers (BAC 2 80 mgldl; mean, I81 mgidl), six (10.3%) received an alcohol-related conviction; (ii) in the 140 crashes in which crash culpability could be assessed, 64.7% of unimpaired drivers (94.6% BAC = 0) were considered culpable compared with 92.7% of impaired drivers (p < 0.001); (iii) although preinjury conviction rates for DWI/DUI, speeding, and reckless driving were significantly higher for impaired drivers, in the postinjury period (2-3 years), the only difference between impaired and unimpaired drivers was a higher alcohol-related conviction rate for the impaired. Littfe is known about injured motorcycle drivers’ alcohol use and crashes. Therefore, we have studied the driving records, crash culpability, and crash convictions of injured hospitalized motorcycle drivers and assessed their use of alcohol. Our methods and findings are presented in this report.
etal.
MATERIALS
AND METHODS
In Maryland, I 1 trauma centers are components of the state’s comprehensive system of emergency medical care, the Maryland Institute for Emergency Medical Services Systems (MIEMSS) (Ramzy 1988). The clinical hub of MIEMSS is the Shock Trauma Center in Baltimore. All injured motorcyclists admitted for treatment to Maryland trauma centers between July 1987 and June 1988 were eligible for this study, which was part of a prospective study of all police-reported motorcycle crashes in Maryland (Shankar et al. 1990). To comply with the Maryland Automated Accident Reporting System (MAARS) (Maryland State Police 1982), state police officers must file a Motor Vehicle Accident Report for any crash in which injury occurs. The reports contain detailed information about crash scenarios, including the number and types of vehicles involved, vehicle condition, lighting and weather conditions, and roadway features and conditions. The reports include both a narrative and diagram description of the crash. Issued citations are recorded. The officer offers an opinion on the report as to primary and secondary driver-related causes of the crash and designates which factor is associated with particular vehicles in the crash. There is a checklist for driver condition, including the items “apparently normal” and “had been drinking.” For this study, Motor Vehicle Accident Reports were obtained from the Maryland State Police. Assessments took into account the above-mentioned information contained in the reports. As previously described (Soderstrom et al. 1990), driver culpability was scored using the five-point “culpability scale” advocated by Terhune (1982). Scores of f and 5 are definitive for culpability assessment: “culpable” (I) indicates that “the subject vehicle was the first to create the dangerous situation” and “neither culpable nor contributory” (5) indicates that the “driver had no responsibility for the accident.” Intermediate scores (2,3,4) are not definitive. Culpability assessments were made by the investigators (CS, PD, MS), who were blinded to BAC results. Driving records from the Maryland Motor Vehicle Administration were reviewed. Violations were grouped into four categories: (i) speeding, (ii) reckless driving (e.g. improper passing, following too closely, failure to yield), (iii) impaired driving (e.g. DUI, DWI, refusal to take a chemical test), and (iv) major license violations (e.g. no license, driving with a suspended or revoked license). Data were analyzed using chi-square tests. To
Crash culpability among injured motorcycle drivers
Table 1. Demographics of injured drivers tested for alcohol compared with all drivers treated BAC obtained (n = 165) Age* Mean <21 yr 21-34 yr 235 yr Mean ISS Died
28.0 yr 16.3% 62.4% 19.4% 15.4 9.6%
Table 3. Single vs. multiple vehicle crashes and alcohol use (N = 165) Single
All drivers (n = 203) 27.7 yri 16.7% 61.5% 20.2% 14.3t 12.6t
*Age not known in three in both groups. tNo significant difference.
713
BAC BAC +
Multiple
No.
%
No.
%
23 47
32.9 67.1
54 41
56.8 43.2
the charge of DWI. Hence, 78 (47.2%) of the drivers in this study were legally impaired. Alcohol use and age
protect patient confidentiality, access to the data base was limited to investigators, and records and reports were kept under lock and key. RESULTS During the study period, 203 motorcycle drivers were admitted to Maryland trauma centers. (More than half [52.7%] were treated at the Shock Trauma Center in Baltimore.) Two hundred of them were men (98.5%). Blood alcohol levels were determined on 165 (81.3%) of the drivers. In Table 1, demographics of drivers in whom a BAC was obtained and of all of the injured drivers are compared. MAARS reports were available foi- all 165 drivers tested for alcohol, and driving records were available for 145 of the 165 drivers tested for alcohol. Those two groups are the focus of the remainder of this report. Alcohol use
Eighty-eight (53.3%) of the drivers tested positive for alcohol use (BAC+) (mean BAC, 144 mg/dl; range, lo-370 mg/dl) (Table 2). For those with a BAC 2 100 mg/dl, the mean was 172 mg/dl. Seventeen (10.3%) had a BAC 2 200 mg/dl. In Maryland, at the time of the study, a BAC of 70-99 mg/dl was consistent with the charge of DUI, and a BAC 2 100 mg/dl was consistent with
The age of 162 drivers was known. Of the 27 drivers under the legal drinking age of 21 years, nine (31.3%) tested positive for alcohol and six (66.7%) of them had a BAC L 100 mg/dl. Of the older drivers, 57.8% were BAC+; of these, 75.6% had a BAC 2 100 mg/dl. Single versus multiple vehicle crashes alcohol use
and
The 42.7% rate of alcohol use among the 96 drivers in multiple vehicle crashes was significantly lower (p < 0.002) than the 68.1% rate among the 69 drivers in single vehicle crashes (Table 3). Culpability
In 150 (90.9%) of the 165 crashes, a definitive culpability score of 1 (culpable) or 5 (neither culpable nor contributory) was determined (Table 4). Of the 70 BAC - drivers, 45.7% were considered culpable of causing the crashes in which they were injured, compared with 67 (82.7%) of the BAC+ drivers (p < 0.001). Among the 60 drivers with a BAC 2 100 mg/dl, 86.7% were considered culpable. All but two of the 41 drivers with BACs 2 150 mg/dl were culpable. Sixty-one (93.8%) of the 65 drivers in single vehicle crashes were considered culpable of causing their crashes. (Defective road conditions, an animal impact [deer], and equipment failure were factors in the other four crashes.) In those crashes, driver culpability was 90.0% among BAC- drivers and
Table 2. BACs of 165 injured motorcycle drivers admitted to Maryland trauma centers
Table 4. Driver culpability and BAC level BAC (mg/dl)
BAC (mg/dl)
Number
%
0
77 10 13 23 42
46.7 6.1 7.9 13.9 25.5
l-69 70-99 100-149 z150
0
l-69
(45?%)
(661j74)
(81.98%)
(867;%)
(54Y%)
(33?3%)
(l&2%)
(13.!%)
70-99
2 100
Culpable Not culpable
714
Table
C. A. SODERSTROM
5. Motorcycle
driver culpability and multiple vehicle crashes
BAC:
BAC-
Single vehicle Culpable Not culpable Multi-vehicle Culpable Not culpable
Single
vs.
No.
%
No.
%
18 2
90.0 10.0
43 2
95.6 4.4
14 36
28.0 72.0
24 I1
68.6 31.4
records
The driving records were complete Maryland histories. There were no significant differences in the age group distributions between the BAC + and BAC - drivers. Hence, driving exposure rates were comparable for both groups of drivers. For each category of violations, a greater percentage of BAC + drivers had preinjury convictions compared to BAC - drivers (Table 6). The differences were highly significant for alcohol/drug and reckless driving convictions. The mean number of impaired driving convictions was over two times higher among BAC + drivers compared to BAC drivers, being 2.8 and 1.2, respectively. Only one of the five BAC - drivers had more than one conviction (two) for such violations; 12 of the 22 BAC + drivers had two or more (two had five each, three had three
6. Preinjury
driving
violations admission Drivers
Speeding (Mean) Reckless (Mean) Alcohol/drug (Mean) Suspended/revoked license (Mean) *NS
= not significant.
7. Crash-related
convictions of drivers and BAC BACs
38 (44.7%) of the 85 drivers involved in multiple vehicle crashes were culpable of their crashes. In those crashes, 28.0% of BAC - drivers were culpable compared to 68.6% of BAC + drivers (p < 0.002).
Table
Table
BAC +
95.6% among BAC + drivers (Table 5). In contrast,
Driving
etal.
and
alcohol
status
on
with violations
BAC (n = 69)
BAC+ (n = 76)
40 (58.0%) (3.3) 30 (43.5%) (2.3) 5 (7.2%) (1.2) 5 (7.2%) (1.4)
56 (73.7%) (3.6) 52 (68.4%) (3.1)
0.05
0.002
(28?t%, (2.8)
0.001
(141:%) (1.4)
NS*
drivers
motorcycle
(mg/dl)
DUI
DWI
BAC (N = 61)* (n = 3)
l-69 (N = 8) (n = 0)
70-99 (N = 10) (n = 2)
PI00 (N = 51) (n = 8)
2 2 0 I$
0 0 0 0
I 0 2t 0
0 4 5
Speeding Reckless DWIiDUIiRef Suspended/ revoked license
I
*N = number of drivers; n = with convictions. t 1 with DUI also received a manslaughter conviction. $Had no license to drive. Ref = refused to submit to chemical test.
each, two had four each, one had six, and another had seven prior to injury). Among the BAC + drivers, five had sustained a total of seven preinjury convictions for fleeing from the police (five) or leaving the scene of a crash (two), compared to one BAC - driver who received a prior conviction for leaving the scene of a crash. Crash
convictions
Of the 145 drivers for whom driving records were available, 130 survived. Crash-related convictions for those drivers are presented in Table 7. Three (4.3%) of the unimpaired drivers (BAC = 0 or < 70 mg/dl) received a total of five crash-related convictions. Ten (16.4%) of the BAC + drivers with illegal BACs received a total of 14 crash-related convictions; seven (11.5%) of these drivers received an alcohol-related conviction. Minor convictions (e.g. not carrying a license) may have been issued but are not listed in Table 7. Convictions
P
of injured
injured
and culpability
Of the 130 surviving drivers with complete driving records, 2 (7.1%) of the 28 unimpaired drivers (BAC = 0, < 70 mg/dl) who were deemed culpable of their crashes received a conviction. Of the 48 impaired culpable drivers (BAC 2 70 mgidl), eight (16.7%) received convictions, six (12.5%) of which were alcohol-related. Police assessment of alcohol crash-related convictions
use, culpability,
and
The police offered an opinion concerning the condition of 44 drivers with a BAC 2 70 mg/dl. On 22 (50.0%) occasions, they indicated that the driver
Crash
culpability
among
“had been drinking.” Among 11 drivers with BACs of 70-99 mg/dl, 5 (45.5%) were assessed to have used alcohol, while among 14 with BACs of loo-149 mg/dl the police assessed that 4 (28.6%) “had been drinking.” Among the 19 drivers with high BACs (2 150 mg/dl), 13 (63.2%) were assessed to have been drinking. Of the 18 drivers who “had been drinking,” and were culpable of their crashes, six (33.3%) received alcohol-related crash convictions. DISCUSSION In this study, the largest of alcohol use among injured motorcycle drivers admitted to hospitals for 53.3% tested positive for alcohol treatment, (BAC+); of those, 88.6% were legally impaired (BAC ~70 mg/dl) and 73.9% had BACs zz 100 mg/dl. The results are similar to the findings of a study of 70 injured motorcycle drivers treated at the MIEMSS Shock Trauma Center two years earlier, 50% of whom were BAC+ and 75% of whom were estimated to have BACs 2 100 mg/dl (Soderstrom et al. 1988). The overall BAC + results in both studies are higher than those from a study of 97 injured cyclists treated between 1975 and 1977 at the Center: 29.9% were BAC + , 72.4% of whom had BACs 2 100 mg/dl (Soderstrom et al. 1979). The figures in the current study are similar to data for 1987 and 1988 from the Fatal Accident Reporting System of fatally injured motorcyclists, of whom 49.4% were BAC + ; 75.5% of that group had a BAC 2 100 mg/dl (NHSTA 1989). The overall 53.3% BAC + rate of this study among injured, hospitalized cyclists is higher than the 32.4% rate for 71 riders (55 drivers) reported by Bried, Cordasco, and Volz (1987) and the 47.1% rate for 51 drivers reported by McLellan and associates (1990). Finally, Luna and colleagues (1984) reported a 38.0% intoxication rate (BAC 2 100 mg/dl) among 92 injured cyclists admitted to a trauma center and tested for alcohol. An additional 47 cyclists were not tested. In the late 197Os, Hurt and colleagues (1981) conducted an extensive study of 900 motorcycle crashes in California. Prospectively, they performed in-depth crash investigations. The current study was limited to a retrospective “in-house” review of police reports. Although the current study lacks the sophistication of the investigation by Hurt et al., the results are similar. The Maryland study showed that motorcyclists involved in single-vehicle crashes were culpable over 90% of the time (compared with two-thirds of cases in the DOT study). Fewer than half of the motorcyclists involved in crashes with another vehicle were deemed culpable in the current study (compared with one-third in the DOT study).
injured
motorcycle
drivers
71.5
Alcohol’s causative role in motorcycle crashes is apparent from the culpability assessment results. Not only were the BAC + drivers found to be culpable at a higher rate compared with BAC- drivers (82.7% vs. 45.7% [p < O.OOl])but also an association between culpability and increasing alcohol level was noted. The alcohol/culpability link was most evident in the finding that more than twice as many BAC + (68.6%) as BAC - (28.6%) drivers (p < 0.002) were deemed culpable in multiple vehicle crashes. The overall alcohol/culpability results of the aforementioned studies of Maul1 and colleagues (1984) and Soderstrom and associates (1990) involving injured automobile drivers are consistent with Baker and Fisher’s (1977) report of fatally injured Maryland motorcycle drivers. The significantly higher rate of preinjury alcohol-related, speeding, and reckless driving convictions noted in this study parallels observations noted among injured automobile drivers treated at the Shock Trauma Center (Soderstrom et al. 1990) and those reported by Maul1 and colleagues (1984). The results of the three studies strongly suggest that previous alcohol-related convictions did not deter the injured from continuing to drive in an impaired state. Further, one should consider that convictions for drunk driving represent only about half of drunk driving arrest episodes (Soderstrom et al. 1990; Maul1 et al. 1984). The 16.4% conviction rate for any crash-related violation for the impaired injured motorcycle drivers in the current study is almost three times less than the 34.5% rate for impaired injured automobile drivers reported previously from the Shock TraumaCenter (Soderstrom et al. 1990). The conviction rate of 11.5% for alcohol-related violations in the current study is comparable to the 10.3% rate in the automobile driver study. The conviction rates in these two MIEMSS Shock Trauma Center studies represent a substantial improvement over the zero conviction rates of injured intoxicated automobile drivers reported by Maul1 and colleagues (1984) and Colquitt and associates (1987). The results of all four studies are eclipsed by the 40.6% alcohol-related conviction rate of injured drivers treated in a Pennsylvania trauma center (Barillo et al. 1990). Maul1 and his colleagues (1984) summarized well the legal, administrative, and psychological factors (including empathy for the injured patient) that present obstacles to the prosecution of impaired injured drivers admitted for treatment. In addition, one must consider the extent of the patient’s injuries and their clinical management (including rehabilitation) on the prosecution process. As noted, the mean
ISS for the study group was 15.4 and the fatality rate was 10%. That degree of injury may have precluded prosecution and trial in a timely fashion for many of the surviving patients, a factor that was not studied. Barillo and colleagues (1990) emphasized the need for such drivers to be identified by the police after the crash. In the present study, among the 33 drivers with BACs 2 100 mg/dl, in which driver condition was assessed, the police concluded that only 51.5% “had been drinking.” In the previous study from the Shock Trauma Center (Soderstrom et al. 1990) the police did not ascertain drinking in 29.3% of impaired injured drivers. Problems of police identification of alcohol use among both fatally (Baker and Fisher 1977) and nonfatally injured drivers (Maul1 et al. 1984) have been documented before. Identification of intoxicated motorcycle drivers is important for both legal (prosecution) and clinical (patient management) reasons. As noted previously, a BAC is routinely obtained at the MIEMSS Shock Trauma Center for patient management. Assessment of patients with elevated BACs (2 70 mg/dl) by the center’s substance abuse counselor for alcoholism and psychoactive substance use disorders is a standard of clinical practice (Soderstrom and Cowley 1987). To reduce morbidity and mortality from drunk driving, the authors advocate systems in which legal and clinical protocols are designed to complement each other. Acknowledgements-Portions of this study were supported by Grant DTNH22-87-Z-07490 from the U.S. Department of Transportation, National Highway Traffic Safety Administration. The
final report (DOT HS 807 612)for fulfillment of grant requirements is available from the National Technical Information Service. The authors thank the Maryland State Police for supplying crash reports and the driver records section of the Maryland Motor Vehicle Administration for providing driver records. We also thank John New for management of the Maryland Trauma Registry and Linda Kessehing for editorial assistance.
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economic parameters of motorcycle-induced trauma. Clin. Orthop. 223:252-256; 1987. Coiquitt, M.; Fielding, L. P.; Cronan, J. F. Drunk drivers and social injury. N. Engl. J. Med. 317:1262-1266; 1987. Council on Scientific Affairs, American Medical Association. Alcohol and the driver. J.A.M.A. 255:522-527; 1986.
Hurt, H. H., Jr.; Ouellet, J. V.; Thorn, D. R. Motorcycle accident cause factors and identification of countermeasures. Volume I: Technical report. Publication DOT HS-805 862. Washington, DC: National Highway Traffic Safety Administration, U.S. Department of Transportation; 198 1. Luna, G. K.; Maier, R. V.; Sowder, L.; et al. The influence of ethanol intoxication on outcome of injured motorcyclists. J. Trauma 24:695-700; 1984. Macdonald, S.; Pederson, L. L. Occurrence and patterns of driving behaviour for alcoholics in treatment. Drug Alcohol Depend. 22:15-25; 1988. Maryland State Police. Maryland Automated Accident Reporting System: MAARS Form Preparation Manual. Pikesville, MD: MSP Headquarters; September 21, 1982. Maull, K. I.; Kinning, L. S.; Hickman, J. K. Culpability and accountability of hospitalized injured alcohol-impaired drivers. J.A.M.A. 252:1880-1883; 1984. McLellan, B. A.; Vingilis, E.; Liban, C. B.; et al. Blood alcohol testing of motor vehicle crash admissions at a regional trauma center. J. Trauma 30:418-421; 1990. Miller, B. A.; Whitney, R.; Washousky, R. Alcoholism diagnosis for convicted drinking drivers referred for alcoholism evaluation. Alcohol. Clin. Exp. Res. 10:651-656; 1986. NHTSA (National Highway Traffic Safety Administration.) Fatal Accident Reporting System 1988: A review of information on fatal traffic crashes in the United States in 1988. DOT HS 807 507. Washington, DC: U.S. Department of Transportation; December 1989. NHTSA. National Accident Sampling System-1986: A report on traffic crashes and injuries in the United States. DOT HS 807 296. Washington, DC: U.S. Department of Transportation; July 1988. Ramzy, A. I. The Maryland emergency medical services system: An update. Md. Med. J. 37:517-520; 1988. Shankar, B. S.; Dischinger, P. C.; Ramzy, A. I.; SoderStrom, C. A.; Clark, C. C. Helmet use, patterns of injury and medical outcome among motorcycle drivers in Maryland. Proceedings of the Association for the Advancement of Automotive Medicine. Des Plaines, IL: AAAM; 1990: 13-34. Soderstrom, C. A.; Birschbach, J.; Dischinger, P. C. Injured drivers and alcohol use: Culpability, convictions, pre- and post-crash driving history. J. Trauma 30:1208-1214; 1990. Soderstrom, C. A.; Cowley, R A. A national alcohol and trauma center survey: Missed opportunities, failures of responsibility. Arch. Surg. 122: 1067-1071; 1987. Soderstrom, C. A.; DuPriest, R. W., Jr.; Benner, C.; et al. Alcohol and roadway trauma: Problems of diagnosis and management. Am. Surg. 45:129-136; 1979. Soderstrom, C. A.; Trifillis, A. L.; Shankar, B. S.; Clark, W. E.; Cowley, R A. Marijuana and alcohol use among 1023 trauma patients. Arch. Surg. 123:733-737; 1988. Terhune, K. W. An evaluation of crash culpability to assess alcohol and drug impairment effects. Proceedings of the American Association for Automotive Medicine 26:329-348, 1982. Terhune, K. W.; Fell, J. C. The role of alcohol, marijuana, and other drugs in the accidents of drivers. NHTSA Technical Report DOT-HS-806- 18 1. Twenty-fifth Proceedings of the American Association of Automotive Medicine, October l-3, 1981.