Helmet Use Improves Outcomes After Motorcycle Accidents MARGIE A. MURDOCK, RN, MSN, and KENNETH WAXMAN, MD, Orange, California
To determine the effects of motorcycle helmet use on the outcome of patients admitted to a Level I trauma center, we studied patient outcomes and demographic and epidemiologic variables of 474 patients injured in motorcycle collisions and treated at such a center over a 45-month period. Of those involved in a motorcycle collision, 50% were not wearing a helmet, 230/o were wearing a helmet, and in 270/o helmet use was unknown. Those who were wearing a helmet had fewer and less severe head and facial injuries, required fewer days on a ventilator, and sustained no serious neck injuries; fewer patients who wore helmets were discharged with disability, and hospital charges were lower. These data support the need for both increased public education regarding helmet use and mandatory helmet use legislation. (Murdock MA, Waxman K: Helmet use improves outcomes after motorcycle accidents. West J Med 1991 Oct; 155:370-372)
andatory motorcycle helmet laws have been repealed or weakened in many states over the past several years. These repeals have been associated with an increased number of patients sustaining serious head injuries. 1-4 Public debate persists regarding the efficacy of helmet use in preventing death and disability. There is also argument that helmet use may be associated with an increased incidence of neck injury. To address these issues, we examined the outcomes of patients admitted to our trauma center after motorcycle accidents. It was our goal to examine differences in outcome associated with helmet use. Patients and Methods The University of California Irvine Medical Center (UCIMC) is a 493-bed teaching hospital located in Orange County, California. It is one of three designated trauma centers and the only Level I center in the county. Countywide triage guidelines are used in the prehospital setting to identify and designate patients to be sent to a trauma center. The triage criteria are based on the mechanism of injury, vital signs, and other clinical findings. Triage decisions are the responsibility of base station physicians. Trauma registry information is obtained on all designated trauma center patients and entered into a computerized registry, from which the information for this study was derived. The following variables were analyzed: helmet use, age, sex, survival, duration of hospital stay, days in the intensive care unit, days on a ventilator, admission blood alcohol levels, neck injuries, disability status at discharge, insurance status, and hospital charges. In addition, the Abbreviated Injury Scale (AIS) was analyzed. This scale, based on anatomic findings, is used to assess and score injuries in six body regions using a scale of 1 (minor) to 6 (virtually unsalvageable injury).56 Serious injuries receive an AIS score of 3 or above. This scoring was available on 296 patients, 205 without helmets and 91 with helmets. The Student's t test or Fisher's Exact Test was used to evaluate the statistical significance of differences.
Results Over a 45-month period, 3,941 designated trauma center patients were seen at UCIMC. In all, 474 (12%) were involved in a motorcycle collision. Of these, 236 patients (50%) were not wearing a helmet, 111 (23%) were wearing a helmet, and for 127 patients (27%) helmet usage was not documented. Most of the patients (449, or 95%) were male. The age range for the total motorcycle-riding group was from 4 to 66 years; the average age was 25. Patients wearing helmets averaged 26 years of age, and those not wearing them averaged 25 years. Of the helmet users, 97% were male, and 92% of nonhelmeted users were male. Those patients for whom helmet use was not documented were excluded from further analysis. In the helmeted group, 4 patients (4%) had an AIS score in the head and neck category of 3 or more, and 39 patients (19%) in the nonhelmeted group had scores of 3 or more (Table 1). There was thus a statistically significant increased chance of sustaining a serious head injury when not wearing a helmet (P < .001). The AIS category of facial injury scores ranged from 1 to 4. Those patients who were evaluated using the AIS system were reviewed for the incidence of facial injuries. In the helmeted population, 5 patients (5%) with facial injuries had TABLE 1.-Abbreviated Injrwy Scale (AIS) Scores for Head and Nck Injuries in Motorcycle Riders, by Helmet Use (n =296 Rider Wore Helmet, AIS Score' n=91 1 ..........14 7 2..............
Rider Did Not Wear Helmet, n=205
3.............. 4.............. 5..............
3 1 0
8 11 19
'The scoring goes from 1 for least severe to 6 for most severe injury.
From the Department of Surgery, University of California Irvine Medical Center, Orange. Supported in part by the Critical Care Foundation. Reprint requests to Kenneth Waxman, MD, University of California Irvine Medical Center, 101 City Dr S, Orange, CA 92668.
THE WESTERN JOURNAL OF MEDICINE * OCTOBER 1991
* 155 * 4
ABBREVIATIONS USED IN TEXT AIS = Abbreviated Injury Scale UCIMC = University of California Irvine Medical Center
TABLE 3.-Discharge Disabilities in Motorcycle Riders, :: by Helmet Use (n =447) Disability
AIS scores of 1 or 2. In the nonhelmeted group, 36 patients (18%) with facial injury had AIS scores of 1 to 3 (P < .01). One criticism used against wearing a helmet is that helmet use allegedly predisposes to neck injuries.7 Ten patients sustained neck injuries, eight in the nonhelmeted group (3%) and two in the helmeted group (2%) (P = .33) (Table 2). None of these patients sustained permanent spinal cord injury or were discharged with a neurologic deficit. There were seven cervical spine fractures, six in the nonhelmeted group (3%) and one in the helmeted group (1%) (P = .27). In the nonhelmeted group, there was one injury to the larynx and one cricoid cartilage injury. In the helmeted group, one patient sustained a spinal cord contusion. Thus, helmet use was not associated with an increased risk of neck injury. It is our trauma center policy to determine blood ethanol levels on all adult patients. Results were obtained on 103 (93%) of the helmeted patients and 228 (97%) of the nonhelmeted patients. Blood specimens were positive for ethanol in 32 of the helmeted patients (29%), and 23 (72%) of them had levels of 100 mg per dl (22 mmol per liter) or higher, which at the time was considered legally intoxicated in California. In the nonhelmeted group, 110 patients (47%) had a positive blood ethanol level, 75 of them (68%) having levels of 100 mg per dl or higher. The increased use of alcohol by nonhelmeted motorcyclists was statistically significant (P < .005). In all, 152 patients were admitted to a critical care unit, 47 (42%) from the helmeted group and 105 (44%) from the nonhelmeted group (P = .39). In the helmeted group, 9 patients (8%) required ventilatory support, as did 46 patients (19%) from the nonhelmeted group. Thus, nonhelmeted patients were more likely to require ventilatory support (P < .005). Most patients discharged with disability were from the nonhelmet-wearing group: 17 (7%) had substantially decreased cognitive functioning compared with 1 patient (1%) in the helmeted group (P = .005). Additional disabilities in the nonhelmeted group included four patients with leg amputations and one who sustained a cord contusion resulting in lower extremity weakness (Table 3). Four patients in the helmeted group had sustained additional disabilities, two with arm amputations, and one with a leg amputation, and one who was discharged with T-12 paraplegia. A total of 20 patients died, 14 of whom were not wearing a helmet (6%) and 6 (5%) who were. The primary cause of TABLE 2.-Neck Injuries Sustained in Motorcycle Riders, by Helmet Use (n=447) Rider Did Not Wear Helmet, Rider Wore Helmet, n=236 n=111 Neck lnjury Cervical fracture . . Cord contusion ...
0 Larynx Cricoid ..0. 3 (3%) Total ....... ..........
'No patients were discharged with a neurologic deficit
Head injury ...... Arm amputation Leg amputation Paraplegia or lower cord injury Total .......
Rider Wore Helmet, n=11t
RiderDid Not Wear Helmet, n=236
17 0 4
1 22 (9%)
TABLE 4.-Cause of Death in Motorcycle Riders, by Helmet Use (n=447) Cause of Death
Head injury ...... Thoracic injury Abdominal injury. Total ....
Rider Wore Helmet, n= 117 No (*,)
Rider Did Not Wear Helmet, n-236 No. (9b)
1 (1) 3 (3) 2 (2) 6 (5)
12 (5) 2 (1)
0 (0) 14 (6)
death for 12 patients in the nonhelmeted group was the result of head injury (5%), and 2 died of chest injuries. One death (1%) in the helmeted group was the result of head injury, three were due to a transected aorta, and two were caused by intra-abdominal injury (Table 4). There was a significantly greater risk of death from head injury in nonhelmeted riders (P < .05). Hospital charges were collected on each patient after discharge from the hospital (professional fees not included). Charges for the helmeted population totaled $1,793,094; the average charge per patient was $16,154. The total hospital charge for the nonhelmeted group was $7,057,580, with the average charge per patient being $29,905. The insurance status of each patient was recorded at the same time as charges. A large percentage of patients in both groups was uninsured or had state or local indigent reimbursement that was below actual costs. Adequate reimbursement occurred for 53% of helmeted patients and 40% of the nonhelmeted group (P < .05). Adequate funding was considered the insurance grouping of private insurance (third-party payers; private insurance, health maintenance organizations, and Workers' Compensation) and CHAMPUS [Civilian Health and Medical Program of the Uniformed Services].
Discussion Motorcycle riders are typically men in their mid-20s. Unless laws mandating helmet use are in place, these riders are not likely to wear helmets. Our data show that when riders not wearing helmets were brought to our trauma center after accidents, they had increased risks of serious head and facial injuries, prolonged hospital stays requiring ventilatory support, and either died of head injuries or were discharged with a neurologic deficit. These findings are consistent with those of previous reports.3'8'9
6 0 1 1
Our results also indicate that the use of a helmet does not increase the risk of sustaining a neck injury. There was no difference between the groups in the occurrence of neck
A significantly increased number of nonhelmeted patients sustained severe head injury resulting in decreased
MOTORCYCLE HELMET USE
cognitive functioning at the time of discharge. The long-term effect that these disabilities have on society in extended health care costs, custodial care, lost productivity, and emotional and financial burdens on families is impossible to determine accurately, but it is enormous. The overall incidence of death was not statistically different between the groups. This may be somewhat misleading because it is likely that many motorcyclists not wearing a helmet sustained fatal head injuries and died immediately at the scene, were not taken to a trauma center, and were not included in this study. Helmeted riders may have survived more severe multisystem injury because of less severe head injuries, only to die of other injuries in the hospital. The hospital charges for nonhelmeted patients were higher, yet were reimbursed at a lower rate than those of helmeted patients. We find it interesting that patients with CHAMPUS insurance had higher helmet use, perhaps indicating the success of instructions from the local naval base requiring all active duty personnel riding a motorcycle to wear a helmet both on and off duty. Helmet use was effective in preventing death and disability from head injury in patients brought to our trauma center. There appeared to be no increased risk of neck injury in-
volved with helmet use. This study and other published data support the need for increased public education regarding helmet use and mandatory helmet use legislation. 1-'8"0 The justification for this includes not only individual safety but also the costs to society associated with nonhelmeted users' increased costs of hospital care and prolonged disability. REFERENCES 1. Chenier TC, Evans L: Motorcyclist fatalities and the repeal of mandatory helmet wearing laws. Accid Anal Prev 1987; 19:133-139 2. McSwain NE, Lummis M: Impact of repeal of motorcycle helmet law. Surg Gynecol Obstet 1980; 151:215-224 3. McSwain NE, Petrucelli E: Medical consequences of motorcycle helmet nonusage. J Trauma 1984; 24:233-236 4. Sosen DM, Sack JJ, Holmgreen P: Head injury associated deaths from motorcycle risks-Relationship to helmet-use laws. JAMA 1990; 264:2395-2399 5. Baker SP, O'Neill B: The injury severity score: An update. J Trauma 1976; 16:882-885 6. Copes WS, Champion HR, Sacco WJ, Lawnick MM, Keast SL, Bain LW: The Injury Severity Score revisited. J Trauma 1988; 28:69-77 7. Krantz KP: Head and neck injuries to motorcycle and moped riders-with special regard to the effect of protective helmets. Injury 1985; 16:253-258 8. Bachulis BL, Sangster W, Gorrell G, Long WB: Patterns of injury in helmeted and nonhelmeted motorcyclists. Am J Surg 1988; 155:708-711 9. Evans L, Frick MC: Helmet effectiveness in preventing motorcycle driver and passenger fatalities. Accid Anal Prev 1988; 20:447-458 10. Rivara FP, Dicker BG, Bergman AB, Dacey R, Herman C: The public cost of motorcycle trauma. JAMA 1988; 260:221-223