ORIGINAL CONTRIBUTION
motorcycle accidents
A
Population-Based Study of Motorcycle Injury and Costs From the Connecticut Childhood Injury Prevention Center,* and the
Mary Braddock, MD, MPH *t Robert Schwartz, MD, MPH*
Departments of Pediatricst and
Garry Lapidus, PA-C, MPH *t
Emergeney Medicine/Trauma,¢
Leonard Banco, MD *t
Hartford, Connecticut.
Lenworth Jacobs, MD, MPH*
Receivedfor publication August 30, 1991. Revision receivedNovember 12, 1991. Acceptedfor publication December 2, 1991. Presented at the Societyfor Academic Emergency Medicine Annual Meeting in Washington, DC, May 1991.
Study objective: To provide a population-based injury and cost profile for motorcycle injury in Connecticut. Design: Population-based retrospective epidemiologic review of Connecticut death certificates, hospital discharge data, and police accident reports. Results: Connecticut death certificates identified 112 deaths from motorcycle injuries for an annual death rate of 1.2 per 100,000 persons. Death rates were highest among 20- to 24-year-old men. Nonhelmeted motorcyclists were 3.4-fold more likely to die than were helmeted riders (P< .05). An estimated 2,361 motorcycle-related hospital discharges resulted in an annual hospitalization rate of 24.7 per 100,000 persons. Head, neck, and spinal injuries accounted for 22% of all injuries. Total costs exceeded $29 million; 29% of hospitalized patients were uninsured, and 42% of the cost was not reimbursed to the hospitals. Conclusion: Motorcycle injuries contribute significantly to Connecticut's mortality, morbidity, and medical costs. Our study suggests that a uniform helmet law would save an estimated ten lives and prevent more than 90 nonfatal injuries in Connecticut each year at a cost savings to the state of $5.1 million. These data are crucial in advocating re-enactment of motorcycle helmet laws. [Braddock M, Schwartz R, Lapidus G, Banco L, Jacobs L: A population-based study of motorcycle injuries and costs. Ann Emerg Med March 1992;21:273-278.]
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ANNALS OF EMERGENCY MEDICINE 21:3 MARCH 1992
MOTORCYCLE
INJURIES
Braddock et al
INTRODUCTION Motorcycle crashes are an important cause of fatal injury in the United States. In 1989, 3,036 motorcycle fatalities occurred, representing 7% of all motor vehicle deaths. Per vehicle mile traveled, the number of motorcycle-related deaths is approximately 19-fold the number for automobiles. More than half of all motorcycle deaths occurred in 16- to 29-year-old men. 1 Motorcycle fatalities are only the tip of the injury severity spectrum. For every motorcycle death, there are 17 motorcycle injuries severe enough to require hospital admission and 90 additional injuries that require emergency department treatment. 2 In 1989, there were an estimated 26,000 motorcycle injuries classified as severe and an additional 56,000 classified as mild or moderate according to the National Accident Sampling System.3 The majority of fatal and severe motorcycle-related injuries are due to head trauma. 4 7 Although it is well known that motorcycle helmets are effective in preventing or reducing the severity of motorcycle-related head injuries, between 1975 and 1983, 28 states either weakened or repealed their motorcycle helmet use laws. Connecticut's mandatory motorcycle helmet use law was repealed in 1976. In mid1989, a partial motorcycle helmet law mandating helmet use by motorcycle operators and riders under the age of 18 years was adopted.7-9 Motorcycle injuries generate enormous costs in acute medical care, rehabilitation, disability, and lost productivity. Several studies have documented that a high proportion of injured motorcyclists are uninsured and that a significant portion of their total medical care costs, including rehabilitation and readmission for acute problems, is paid by public funds, v-13 Most studies, however, describe the experiences of a single trauma center, which may not he representative of the entire population at risk for motorcycle injury and may not accurately reflect the extent of the problem.10.14-16 The purpose of our study was to provide a population-based injury and acute care cost profile for fatal and nonfatal motorcycle collisions occurring in Connecticut.
MATERIALS AND METHODS Demographic data on fatal motorcycle injuries from 1985 through 1987 were obtained from Connecticut state death certificates, using external cause of death codes (E-codes) E810 through E819 (.2, .3) and E822 through E825 (.2, .3) in the International Classification of Disease Sjstem (ICD-9-CM). 17 Police accident reports for all fatal motorcycle collisions occurring in the state (1985 through 1989) were obtained from the
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Connecticut Department of Transportation and provided information regarding hehnet usage. No effort was made to correlate data from Connecticut state death certificates and police accident reports for deaths during 1985 through 1987. Hospital discharge data (fiscal years 1987 through 1989) were obtained from the Connecticut Health InfmTnation Management and Exchange, the statewide data base of the Uniform Hospital Discharge Data Set, using the same E-codes listed above for fatal motorcycle injuries. Information abstracted from this data base included age, sex, type of injury, length of stay, service utilization, hospital charges, and patient payor classification. Connecticut's 36 acute care hospitals varied in the extent that their records included an E-code (0.4% to 97.9%). Approximately half of all injury discharges (55.2%) had an associated E-code. To minimize the selection bias that might occur in hospitals with low E-code reporting and to obtain valid statewide estimates of motorcycle injuries, only data from hospitals with 70% or more of their injury discharge records containing an associated E-code were analyzed (12) . These hospitals were a representative mix of community and trauma center hospitals. The number of injury discharge records with E-codes fiom the selected hospitals represented 36% of the statewide injury discharge total. The number of motorcycle injuries statewide was estimated by dividing the number of motorcycle injuries from the selected hospitals by 0.36. All reported results concerning hospitalization data reflect this 0.36 weighting factor. No adjustments were made for out-of-state residents who may have been admitted to Connecticut hospitals or for Connecticut residents who may have been admitted to hospitals outside the state. The 1985 Connecticut population projections data were used to calculate annualized age- and sex-specific death and hospitalization rates per 100,000 persons. 18 The number of registered motorcycle operators in Connecticut was obtained fiom the 1990
Motorcycle Statistical Annual. 19 Collision death rates for helmeted versus nonhelmeted motorcyclists were calculated using 95% confidence intervals. The diagnosis-related groups (DRGs)-based all-payor system used during fiscal years 1987 through 1989 was used to estimate hospital charges that were reimbursed. The DRG weights, rates, and outlier definitions for one large acute care hospital in Connecticut were applied to the study patient population to obtain an estimate of the percentage of charges that were not reimbursed. The weights and rates from the institution used were 0% to 5% more than those for other hospitals in Connecticut; therefore, the final result approximated the maximum amount reimbursed and might have been an underestimate of the true losses to Connecticut's hospitals. 1~
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To estimate the injury severity of the patients involved in motorcycle crashes during the study period, the data set was applied to a computer program that converts patients' ICD-9-CM diagnostic codes to the Abbreviated Injury Scale, 1990 revision (AIS 90). 2o The computer program reads all ICD-9-CM N-codes and converts them to an AIS body region and severity score. The program then calculates the Injury Severity Score (ISS) for each patient. 21
RESULTS During 1985 through 1987, 112 Connecticut death certificates identified motorcycle injury as the external cause of death, resulting in 4,954 years of potential life lost and an annual death rate of 1.2 per 100,000 persons. The annual death rate per 10,000 registered motorcycle operators was 6.7. The distribution of fatal motorcycle injuries by age and sex is shown (Table 1). Death rates were highest among persons 20 to 24 years old (4.3%). The death rate for males was 23-fold that for females (2.3 vs 0.1). Table 1. Motrocycle injury death rates per 100,000 population by age and sex, Connecticut, 1986 through 1988 Age Group 0-14 15-19 20-24 25-29 30-34 35-39 40-44 45+ Total
No. of Deaths
Rate
1 21 34 29 18 5 2 4 112
0.1 2.7 4.3 3.5 2.1 0.7 0.3 0.1 1.2
611,510 255,820 265,220 274,870 268,240 243,710 208,480 1,871,390 3,190,240
107 5
2.3 0.1
1,526,620 1,663,620
Table 2. Estimated motorcycle injury hospitalization rates per 100,000 population by age and sex, Connecticut,fiscal years 1987 through 1989" Age Group 0-14 15-19 20-24 25-29 30-34 35-39 40-44 45+ Total
No. of Injuries 114 569 894 578 294 156 78 150 2,833
Rate
Population
0.2 74.2 112.4 70.1 37.9 21.3 12.4 4.7 29.6
911,510 255,820 265,220 274,870 259,240 243,710 208,480 1,071,390 3,190,240
52.0 5.2
1,526,620 1,663,620
Sex Male 2,597 Female 236 *Data reflect 0.36 weighting factor
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injuries included such intracranial injuries in the absence of skull or facial bone fractures. •
Population
Sex Male Female
The outcome of motorcycle crashes varied by helmet use. Police accident reports indicated that nonhelmeted motorcyclists involved in collisions were 3.4-fold more likely to die than were helmeted riders (26.7 + 1.0 vs 7.9 _+2.2 deaths per 1,000 crashes [95% confidence intervals]). During fiscal years 1987 through 1989, after adjustment with the 0.36 weighting factor, there were an estimated 2,833 discharges from Connecticut hospitals resuhing from motorcycle-related injuries. The estimated annual hospitalization rate was 29.6 per 100,000 persons. Hospitalization rates were highest among persons 20 to 24 years old and among men (Table 2). The distribution of motorcycle injuries by principal diagnosis is given (Table 3). These data reflect the 0.36 weighting factor previously described. Head, neck, and spine injuries accounted for nearly one-fourth of all injuries (22%). Thirty-two percent of head, neck, and spine injuries involved skull or facial fractures, and 6% of vertebral fractures included spinal cord injuries. Seventy-three percent of patients with skull or facial fractures had an intracranial injury such as a cerebral laceration and contusion or intracranial hemorrhage. An additional 14% of head
Table 3. Percent of motorcycle ir~juriesby principal diagnosis * No. of Injuries
%
636 278 608 39 308 136 2,006
8.9 3.0 6.6 0.4 3.3 1.5 21.7
839 1,589 192 28 2,647
9.1 17.2 2.1 0.3 28.6
Internal injury Open wounds Blood vessel or nerve injury Contusions or superficial injury Crushing Nerve injury Total
536 1,189 56 297 22 64 2,164
5.8 21.9 0.6 3.2 0.2 0.7 23.4
Other
2,433
26.3
Total All Injuries
9,250
100.0
Head/Neck/Spine Skull/facial fracture Intracrania[ nenfracture Vertebral fracture only Vertebral fracture with spinal cord injury Concussion Eye iniury
Total Extremities Upper limb fracture Femur or lower limb fracture Dislocations Traumatic amputations Total
Internal Organs/Soft Tissues
*Data reflect 0.36 weighting factor.
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Nearly one third of all injuries were to the extremities, with more than 60% involving femur and lower limb fractures. Internal injuries comprised approximately 6% of the total (536). Nearly one fourth of these involved a traumatic pneumothorax/ hemothorax. The kidney (19%), heart and lung (18%), and spleen (11%) were other internal organs that were frequently injured. Mean AIS score is given by body region (Table 4). Head (2.7), chest (2.7), and abdominal (2.6) injuries were more severe than injuries to other body regions. The extremities were the most frequently injured body region, although injuries were less severe (1.7). Mean ISS score for all hospitalized motorcycle-related injuries was 9.7. A total of 29,005 hospital days, including 3,542 ICU days, were used during the study period[ These data were derived using the 0.36 weighting factor. The median length of stay was five days (range, one to 153 days; mean, 10.2 days). The number and type of procedures required by patients hospitalized with motorcycle-related injuries are given (Table 5). These data reflect the 0.36 weighting factor. More than one fourth of operations on the musculoskeletal system involved reduction of fractures and dislocations. Approximately 16% of miscellaneous diagnostic and therapeutic procedures included diagnostic radiology-, nuclear medicine, and other related techniques. Physical, occupational, and respiratory therapy comprised 11% of the total. Table 4.
AIS by body region Body Region
Head Face Chest Abdomen Extremity External
Mean AIS
2.7 1.5 2.7 2.6 1.7 1.0
Table 5.
Percentage of motorcycle injuries by procedure * Procedure Involvement
Nervous system Eye, ear, nose, mouth, and pharynx Respiratorysystem Cardiovascular, heroic, and lymphatic system Digestive system Genitourinary system Musculoskeletal system Integumentarysystem Miscellaneous diagnostic and therapeutic Total
No. of Procedures
230 203 147 125 t65 62 2,621 1,108 1,980 6,504
*Data reflect 0.36 weighting factor.
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2 1 : 3 ANNALS OF EMERGENCY MEDICINE
%
3.5 3.1 2.3 1.9 2.6 1.0 38.6 17.0 30.4 100.0
The total cost for hospitalized patients, calculated with the 0.36 weighting factor, exceeded $29.3 million. Twelve percent of the total ($3.5 million) was generated by operating room charges; 2% was computed tomography charges; and 6% was ICU charges. Sixty percent of hospitalized patients had commercial insurance, and 29% had no insurance. Using Connecticut's DRG-based all-payor system, 42% of the cost of caring for patients admitted with motorcycle-related injuries ($12.3 million) was not reimbursed to the hospitals. DISCUSSION
Motorcycle injuries are a significant cause of morbidity and mortality in Connecticut and primarily affect young men. A high proportion of motorcycle injuries are serious, reflecting the magnitude of kinetic energy transferred during the crash to the motorcycle operator or passenger. Head injuries are an important component of the motorcycle injury profile, representing nearly one fourth of all injuries and contributing significantly to fatality and overall morbidity. Unfortunately, Connecticut has not reinstated its motorcycle helmet law despite five attempts during the last 12 legislative sessions to do so. In 1989, the state adopted a partial motorcycle helmet law mandating helmet use by motorcycle operators and riders 18 years of age or younger. Nevertheless, our own data support national figures indicating that approximately 90% of motorcycle injuries and fatalities occur to persons over the age of 18. 8 In addition, states with partial hehnet laws report lower helmet usage rates among motorcyclists of all ages. 22 Finally, partial helmet laws are exceedingly difficult to enforce, requiring police to estimate, at a distance, the age of a person on a moving motorcycle. The high public cost of motorcycle injuries reported in this study and the well-documented increase in the number and severity of these injuries since repeal of motorcycle helmet laws 5-13 should give substantial impetus to advocates of full motorcycle helmet use laws in Connecticut. Using the National Highway Traffic Safety Administration formula and 1989 Connecticut Department of Transportation figures, a full-use helmet law would save an estimated ten lives and prevent more than 90 nonfatal injuries each year at an annual cost savings to the state of $5.1 million. 22 The failure of Connecticut to reinstate a motorcycle helmet law has created a tremendous financial burden for the state. Hospitals caring for patients with motorcycle injuries are at significant financial risk due to the high proportion of uninsured crash victims and the inadequate reimbursement of DRG-based systems.23,24 These data support other studies that indicate I~
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that a significant portion of the cost for motorcycle injuries requiring hospitalization is paid by the taxpayer.9 15 Furthermore, our cost estimate ($29 million) includes only the direct medical care costs generated by hospitalized motorcyclists; ED treatment, subsequent acute hospitalizations, follow-up care, long-term rehabilitation, disability, and lost productivity are not included and may be substantial.m,14, 25 This study is a population-based profile of motorcycle injuries and costs in Connecticut. The strengths of such a study lie in its ability to characterize and analyze a significant injury problem without the limitations inherent in evaluating the experiences of a single trauma center, which may not be representative of the population at risk, the scope of injuries, and the health care costs. We were able to calculate statewide mortality rates and estimate statewide hospitalization rates due to motorcycle injuries. We were also able to profile the type and severity of motorcycle-related injuries and estimate statewide direct medical care costs. Such data are crucial for health and public policy planners. Nevertheless, there remain several limitations to our data. Statewide mortality rates were calculated using Connecticut death certificate data. Although death certificate information has been considered the gold standard for mortality rate calculation, discrepancies in motorcycle-related deaths between death certificate data and police accident reports have been reported. Sosin et al reported a discrepancy of approximately 25% between the two data sources, resulting in an underestimation of motorcycle fatalities by death certificate records, r A preliminary review of our own data sources suggests that the discrepancy in Connecticut is much greater. During the study period, Connecticut death certificates from 1985 through 1987 identified 112 motorcycle fatalities compared with 214 motorcycle deaths reported by police accident reports. Further research is under way to determine the cause of this discrepancy. Our figures represent statewide estimations of nonfatal motorcycle injuries and costs. Estimation was necessary due to nonuniform recording of E-codes on hospital discharge records. Among Connecticut's 36 acute care hospitals, the percentage of hospital discharge records containing an E-code varied from 0.4% to 97.9%. In addition to the lack of unifmm reporting of E-codes on hospital discharge records, there is no uniform method for estimating statewide injury totals. Our method of analyzing data only from hospitals with m o I ~ than 70% of records containing E-codes was derived from unpublished reports; it has not been standardized. Given the wide variation in the use of E-codes, an agreed-on method for statewide injury total
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estimation must be adopted if more studies analyzing populationbased data are to be performed. Ahernatively, mandating the use of E-codes on hospital discharge and ED records would vastly improve the quality of infm~ation that could be retrieved from these sources. A third limitation of our data is the use of only hospital records to determine nonfatal motorcycle injury severity and cost. Although one can safely assume that the most severely injured motorcyclists are admitted to the hospital, the resulting injury profile excludes a large proportion of injured patients who are treated in the ED and released. Studies report that between one fourth and one half of injured motorcyclists require hospital admission.26, 2v Our study underestimates the impact of motorcycle injuries in Connecticut because the number and cost of treating injured motorcyclists who are not admitted to the hospital are not readily available. Bach and Wyman estimated that if only 10% of injured motorcyclists required hospitalization, the national costs of motorcycle injury- would be $263 millionJ ¢ One additional problem with motorcycle injury hospital discharge data in Connecticut is that helmet use is not included. Therefore, we were not able to compare injury severity or cost based on helmet use. Finally, a potential limitation to our study is the decision not to exclude nonresidents from the analysis of motorcycle-injured patients hospitalized in the state. We made the assumption that the number of nonresidents hospitalized in Connecticut was small and would approximate the number of Connecticut residents hospitalized outside the state; in effect the two groups would cancel each other out and provide a true population-based, nonfatal injury profile. This assumption held true for the largest major trauma center in the state, where more than 90% of motorcycle-injured patients were state residents. Therefore, we believe that our estimated rates for hospitalization due to motorcycle injuries reflect a population-based experience.
CONCLUSION Motorcycle crashes are an important cause of death and morbidity in Connecticut. The direct medical care costs associated with motorcycle crashes are high, and the hospitals caring for these patients are not reimbursed adequately. A significant proportion of fatal and serious nonfatal injuries results fiom head injury that can be prevented through use of motorcycle helmets. The information presented in this study should enhance legislative efforts to re-enact a full motorcycle helmet law in Connecticut. I
The authors thank Gene lnterlandi and Mario Tonarelli for their assistance in providing data from the Connecticut Departmen t of Transportation.
ANNALS OF EMERGENCY MEDICINE 2 1 : 3 MARCH 1992
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INJURIES
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I
REFERENCES
Address for reprints: Garry Lapidus, PA-C, MPH, Connecticut Childhood Injury
/. US Department of Transportation, National Highway Traffic Safety Administration: Fatal Accident Reporting System.Washington, DC, DOT.1989. 2. BaranchikJ, Chatterjee F, Greene-CraddenY, et ah Motor vehicle trauma in Northeastern Ohio: I. Incidence and outcome by age, sex, and road-use category. Am J Epidemiol 1986;123:846-861. 3. US Department of Transportation, National Highway Traffic Safety Administratian: General Estimates System 1989."A Review of Information on Police-Reported Traffic Crashesin the United States. Washington, DC, DOT, publication No. HS 807-665, December 1990. 4. Hurt, H, Ouelett J, Them D: Motorcycle Accident Causeand Factors and Identification of Countermeasures: Volume 1, TechnicalReport. Washington, DC, US Department of Transportation, National Highway Traffic Safety Administration, January 1981. 5. Bachulis B, Sangster W, Gorrell G, et al: Patterns of injury in helmeted and nonhelmeted motorcyclists. Am J Surg 1988;155:708-711. 8. Heiiman D, Weisbuch J, Blair R, eta/: Motorcycle-@ated trauma and helmet usage in North Dakota. Ann Emer9Mad 1982;11:659-664. 7. Sosin DM, SacksJ. Holmgreen P: Head-injury associated deaths from motorcycle crashes: Relationship te helmet-use laws. JAMA 1990;264:2395-2399. 8. US Department of Transportation, National Highway Traffic Safety Administration: The Effect of Helmet Law Repeal.Washington, DC, DOT publication No. HS 807-605, December 1986. 9. Watson G, Zader P, Wilks A: Helmet use, helmet-use laws, and motorcycle fatalities. Am J Public Health 1981;71:297-30g. 10. Rivara F. Dicker B, BergmanA, et al: The public cost of motorcycle trauma. JAMA 1988;260:221-223. 11. Muller A: Evaluation of the costs and benefits of motorcycle helmet laws. Am J Public Health 1980;78:586-592. 12. US Department of Transportation, National Highway Traffic Safety Administration: A Report to Congresson the Effect of Motorcycle Helmet Use Law RepeaI--A Case for Helmet Use. Washington, DC, DOT publication No. HS 805-312, April 1980. 13. McSwain N, Belles A: Motorcycle helmets--Medical costs and the law. J Trauma 1990;30:1189-1199. 14. Bach B, Wyman E: Financial charges of haspitalized motorcyclists at the Massachusetts General Hospital. J Trauma1986;26:343 347. 15. Bray T, SzaboR, Timmerman L, et al: Cost of orthopedic injuries sustained in motorcycle accidents. JAMA 1985;254:2452-2453. 16. Dried JM, CordascoFA, Volz RG: Medical and economic parameters of motorcycle-induced trauma. Clin OrthopRelat Res 1987;223:252-258. 17. The IntematienalClassification of Diseases, 9th Revision, ClinicalModification. Washington, DC, US Department of Health and Human Services, publication No. PHS 80 1260,1980. 18. State of Connecticut Office of Policy and Management: ConnecticutPopulation Projections. Hartford, Connecticut, Connecticut State Data Center, series 89.1, June 1989. 19. Motorcycle industry Council: 1990Motorcycle Statistical Annuah 1989Motorcycle Accident Statistics. Irvine, California, Motorcycle Industry Councit, 1990, p 38. 20. American Association for Automative Medicine: TheAbbreviated Injury Scale, 1990Revision. Des P]aines, Illinois, AAAM, 1990. 21. Benson L: Methods for Evaluating Injury Severity. New Haven, Connecticut,Yale University School of Public Health, 1991. Thesis. 22. US Department of Transportation, National Highway Traffic Safety Administration: A Model for Estimating the EconomicSavings from IncreasedMotorcycle Helmet Use. Washington, BC, DOT publication No. HS 807-251, March 1988. 23. Jacobs LM, Schwartz RJ: The impact ef prospective reimbursement on trauma centers. Arch Surg 1986;121:479-483. 24. Bennett DR, Jacebs LM, and Schwartz RJ: Incidence, costs, and DRG-basedreimbursement for traumatic brain injured patients: A 3-year experience. J Trauma1989;29:556-565. 25. Rice M, Mackenzie E, and Associates: Cost of Injury in the United States (a report to Congress).San Francisco,California, Institute for Health and Aging, University of California; Baltimore, Maryland, The Johns Hopkins University, 1989. 26. Haddad JP, EchaveV, Brown R, et al: Motorcycle accidents: A review of 77 patients treated in a three month period. J Trauma1978;16:550-556. 27. Najjar D: A ComprehensiveAnalysis of Motorcycle Accident Data. Washington, DC, National Center for Statistics and Analysis, September 1980.
Prevention Center, 80 Seymour Street, Hartford, Connecticut.
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motorcycle accidents
A
Population-Based Study of Motorcycle Injury and Costs From the Connecticut Childhood Injury Prevention Center,* and the
Mary Braddock, MD, MPH *t Robert Schwartz, MD, MPH*
Departments of Pediatricst and
Garry Lapidus, PA-C, MPH *t
Emergeney Medicine/Trauma,¢
Leonard Banco, MD *t
Hartford, Connecticut.
Lenworth Jacobs, MD, MPH*
Receivedfor publication August 30, 1991. Revision receivedNovember 12, 1991. Acceptedfor publication December 2, 1991. Presented at the Societyfor Academic Emergency Medicine Annual Meeting in Washington, DC, May 1991.
Study objective: To provide a population-based injury and cost profile for motorcycle injury in Connecticut. Design: Population-based retrospective epidemiologic review of Connecticut death certificates, hospital discharge data, and police accident reports. Results: Connecticut death certificates identified 112 deaths from motorcycle injuries for an annual death rate of 1.2 per 100,000 persons. Death rates were highest among 20- to 24-year-old men. Nonhelmeted motorcyclists were 3.4-fold more likely to die than were helmeted riders (P< .05). An estimated 2,361 motorcycle-related hospital discharges resulted in an annual hospitalization rate of 24.7 per 100,000 persons. Head, neck, and spinal injuries accounted for 22% of all injuries. Total costs exceeded $29 million; 29% of hospitalized patients were uninsured, and 42% of the cost was not reimbursed to the hospitals. Conclusion: Motorcycle injuries contribute significantly to Connecticut's mortality, morbidity, and medical costs. Our study suggests that a uniform helmet law would save an estimated ten lives and prevent more than 90 nonfatal injuries in Connecticut each year at a cost savings to the state of $5.1 million. These data are crucial in advocating re-enactment of motorcycle helmet laws. [Braddock M, Schwartz R, Lapidus G, Banco L, Jacobs L: A population-based study of motorcycle injuries and costs. Ann Emerg Med March 1992;21:273-278.]
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ANNALS OF EMERGENCY MEDICINE 21:3 MARCH 1992
MOTORCYCLE
INJURIES
Braddock et al
INTRODUCTION Motorcycle crashes are an important cause of fatal injury in the United States. In 1989, 3,036 motorcycle fatalities occurred, representing 7% of all motor vehicle deaths. Per vehicle mile traveled, the number of motorcycle-related deaths is approximately 19-fold the number for automobiles. More than half of all motorcycle deaths occurred in 16- to 29-year-old men. 1 Motorcycle fatalities are only the tip of the injury severity spectrum. For every motorcycle death, there are 17 motorcycle injuries severe enough to require hospital admission and 90 additional injuries that require emergency department treatment. 2 In 1989, there were an estimated 26,000 motorcycle injuries classified as severe and an additional 56,000 classified as mild or moderate according to the National Accident Sampling System.3 The majority of fatal and severe motorcycle-related injuries are due to head trauma. 4 7 Although it is well known that motorcycle helmets are effective in preventing or reducing the severity of motorcycle-related head injuries, between 1975 and 1983, 28 states either weakened or repealed their motorcycle helmet use laws. Connecticut's mandatory motorcycle helmet use law was repealed in 1976. In mid1989, a partial motorcycle helmet law mandating helmet use by motorcycle operators and riders under the age of 18 years was adopted.7-9 Motorcycle injuries generate enormous costs in acute medical care, rehabilitation, disability, and lost productivity. Several studies have documented that a high proportion of injured motorcyclists are uninsured and that a significant portion of their total medical care costs, including rehabilitation and readmission for acute problems, is paid by public funds, v-13 Most studies, however, describe the experiences of a single trauma center, which may not he representative of the entire population at risk for motorcycle injury and may not accurately reflect the extent of the problem.10.14-16 The purpose of our study was to provide a population-based injury and acute care cost profile for fatal and nonfatal motorcycle collisions occurring in Connecticut.
MATERIALS AND METHODS Demographic data on fatal motorcycle injuries from 1985 through 1987 were obtained from Connecticut state death certificates, using external cause of death codes (E-codes) E810 through E819 (.2, .3) and E822 through E825 (.2, .3) in the International Classification of Disease Sjstem (ICD-9-CM). 17 Police accident reports for all fatal motorcycle collisions occurring in the state (1985 through 1989) were obtained from the
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Connecticut Department of Transportation and provided information regarding hehnet usage. No effort was made to correlate data from Connecticut state death certificates and police accident reports for deaths during 1985 through 1987. Hospital discharge data (fiscal years 1987 through 1989) were obtained from the Connecticut Health InfmTnation Management and Exchange, the statewide data base of the Uniform Hospital Discharge Data Set, using the same E-codes listed above for fatal motorcycle injuries. Information abstracted from this data base included age, sex, type of injury, length of stay, service utilization, hospital charges, and patient payor classification. Connecticut's 36 acute care hospitals varied in the extent that their records included an E-code (0.4% to 97.9%). Approximately half of all injury discharges (55.2%) had an associated E-code. To minimize the selection bias that might occur in hospitals with low E-code reporting and to obtain valid statewide estimates of motorcycle injuries, only data from hospitals with 70% or more of their injury discharge records containing an associated E-code were analyzed (12) . These hospitals were a representative mix of community and trauma center hospitals. The number of injury discharge records with E-codes fiom the selected hospitals represented 36% of the statewide injury discharge total. The number of motorcycle injuries statewide was estimated by dividing the number of motorcycle injuries from the selected hospitals by 0.36. All reported results concerning hospitalization data reflect this 0.36 weighting factor. No adjustments were made for out-of-state residents who may have been admitted to Connecticut hospitals or for Connecticut residents who may have been admitted to hospitals outside the state. The 1985 Connecticut population projections data were used to calculate annualized age- and sex-specific death and hospitalization rates per 100,000 persons. 18 The number of registered motorcycle operators in Connecticut was obtained fiom the 1990
Motorcycle Statistical Annual. 19 Collision death rates for helmeted versus nonhelmeted motorcyclists were calculated using 95% confidence intervals. The diagnosis-related groups (DRGs)-based all-payor system used during fiscal years 1987 through 1989 was used to estimate hospital charges that were reimbursed. The DRG weights, rates, and outlier definitions for one large acute care hospital in Connecticut were applied to the study patient population to obtain an estimate of the percentage of charges that were not reimbursed. The weights and rates from the institution used were 0% to 5% more than those for other hospitals in Connecticut; therefore, the final result approximated the maximum amount reimbursed and might have been an underestimate of the true losses to Connecticut's hospitals. 1~
274/51
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INJURIES
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To estimate the injury severity of the patients involved in motorcycle crashes during the study period, the data set was applied to a computer program that converts patients' ICD-9-CM diagnostic codes to the Abbreviated Injury Scale, 1990 revision (AIS 90). 2o The computer program reads all ICD-9-CM N-codes and converts them to an AIS body region and severity score. The program then calculates the Injury Severity Score (ISS) for each patient. 21
RESULTS During 1985 through 1987, 112 Connecticut death certificates identified motorcycle injury as the external cause of death, resulting in 4,954 years of potential life lost and an annual death rate of 1.2 per 100,000 persons. The annual death rate per 10,000 registered motorcycle operators was 6.7. The distribution of fatal motorcycle injuries by age and sex is shown (Table 1). Death rates were highest among persons 20 to 24 years old (4.3%). The death rate for males was 23-fold that for females (2.3 vs 0.1). Table 1. Motrocycle injury death rates per 100,000 population by age and sex, Connecticut, 1986 through 1988 Age Group 0-14 15-19 20-24 25-29 30-34 35-39 40-44 45+ Total
No. of Deaths
Rate
1 21 34 29 18 5 2 4 112
0.1 2.7 4.3 3.5 2.1 0.7 0.3 0.1 1.2
611,510 255,820 265,220 274,870 268,240 243,710 208,480 1,871,390 3,190,240
107 5
2.3 0.1
1,526,620 1,663,620
Table 2. Estimated motorcycle injury hospitalization rates per 100,000 population by age and sex, Connecticut,fiscal years 1987 through 1989" Age Group 0-14 15-19 20-24 25-29 30-34 35-39 40-44 45+ Total
No. of Injuries 114 569 894 578 294 156 78 150 2,833
Rate
Population
0.2 74.2 112.4 70.1 37.9 21.3 12.4 4.7 29.6
911,510 255,820 265,220 274,870 259,240 243,710 208,480 1,071,390 3,190,240
52.0 5.2
1,526,620 1,663,620
Sex Male 2,597 Female 236 *Data reflect 0.36 weighting factor
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injuries included such intracranial injuries in the absence of skull or facial bone fractures. •
Population
Sex Male Female
The outcome of motorcycle crashes varied by helmet use. Police accident reports indicated that nonhelmeted motorcyclists involved in collisions were 3.4-fold more likely to die than were helmeted riders (26.7 + 1.0 vs 7.9 _+2.2 deaths per 1,000 crashes [95% confidence intervals]). During fiscal years 1987 through 1989, after adjustment with the 0.36 weighting factor, there were an estimated 2,833 discharges from Connecticut hospitals resuhing from motorcycle-related injuries. The estimated annual hospitalization rate was 29.6 per 100,000 persons. Hospitalization rates were highest among persons 20 to 24 years old and among men (Table 2). The distribution of motorcycle injuries by principal diagnosis is given (Table 3). These data reflect the 0.36 weighting factor previously described. Head, neck, and spine injuries accounted for nearly one-fourth of all injuries (22%). Thirty-two percent of head, neck, and spine injuries involved skull or facial fractures, and 6% of vertebral fractures included spinal cord injuries. Seventy-three percent of patients with skull or facial fractures had an intracranial injury such as a cerebral laceration and contusion or intracranial hemorrhage. An additional 14% of head
Table 3. Percent of motorcycle ir~juriesby principal diagnosis * No. of Injuries
%
636 278 608 39 308 136 2,006
8.9 3.0 6.6 0.4 3.3 1.5 21.7
839 1,589 192 28 2,647
9.1 17.2 2.1 0.3 28.6
Internal injury Open wounds Blood vessel or nerve injury Contusions or superficial injury Crushing Nerve injury Total
536 1,189 56 297 22 64 2,164
5.8 21.9 0.6 3.2 0.2 0.7 23.4
Other
2,433
26.3
Total All Injuries
9,250
100.0
Head/Neck/Spine Skull/facial fracture Intracrania[ nenfracture Vertebral fracture only Vertebral fracture with spinal cord injury Concussion Eye iniury
Total Extremities Upper limb fracture Femur or lower limb fracture Dislocations Traumatic amputations Total
Internal Organs/Soft Tissues
*Data reflect 0.36 weighting factor.
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Nearly one third of all injuries were to the extremities, with more than 60% involving femur and lower limb fractures. Internal injuries comprised approximately 6% of the total (536). Nearly one fourth of these involved a traumatic pneumothorax/ hemothorax. The kidney (19%), heart and lung (18%), and spleen (11%) were other internal organs that were frequently injured. Mean AIS score is given by body region (Table 4). Head (2.7), chest (2.7), and abdominal (2.6) injuries were more severe than injuries to other body regions. The extremities were the most frequently injured body region, although injuries were less severe (1.7). Mean ISS score for all hospitalized motorcycle-related injuries was 9.7. A total of 29,005 hospital days, including 3,542 ICU days, were used during the study period[ These data were derived using the 0.36 weighting factor. The median length of stay was five days (range, one to 153 days; mean, 10.2 days). The number and type of procedures required by patients hospitalized with motorcycle-related injuries are given (Table 5). These data reflect the 0.36 weighting factor. More than one fourth of operations on the musculoskeletal system involved reduction of fractures and dislocations. Approximately 16% of miscellaneous diagnostic and therapeutic procedures included diagnostic radiology-, nuclear medicine, and other related techniques. Physical, occupational, and respiratory therapy comprised 11% of the total. Table 4.
AIS by body region Body Region
Head Face Chest Abdomen Extremity External
Mean AIS
2.7 1.5 2.7 2.6 1.7 1.0
Table 5.
Percentage of motorcycle injuries by procedure * Procedure Involvement
Nervous system Eye, ear, nose, mouth, and pharynx Respiratorysystem Cardiovascular, heroic, and lymphatic system Digestive system Genitourinary system Musculoskeletal system Integumentarysystem Miscellaneous diagnostic and therapeutic Total
No. of Procedures
230 203 147 125 t65 62 2,621 1,108 1,980 6,504
*Data reflect 0.36 weighting factor.
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%
3.5 3.1 2.3 1.9 2.6 1.0 38.6 17.0 30.4 100.0
The total cost for hospitalized patients, calculated with the 0.36 weighting factor, exceeded $29.3 million. Twelve percent of the total ($3.5 million) was generated by operating room charges; 2% was computed tomography charges; and 6% was ICU charges. Sixty percent of hospitalized patients had commercial insurance, and 29% had no insurance. Using Connecticut's DRG-based all-payor system, 42% of the cost of caring for patients admitted with motorcycle-related injuries ($12.3 million) was not reimbursed to the hospitals. DISCUSSION
Motorcycle injuries are a significant cause of morbidity and mortality in Connecticut and primarily affect young men. A high proportion of motorcycle injuries are serious, reflecting the magnitude of kinetic energy transferred during the crash to the motorcycle operator or passenger. Head injuries are an important component of the motorcycle injury profile, representing nearly one fourth of all injuries and contributing significantly to fatality and overall morbidity. Unfortunately, Connecticut has not reinstated its motorcycle helmet law despite five attempts during the last 12 legislative sessions to do so. In 1989, the state adopted a partial motorcycle helmet law mandating helmet use by motorcycle operators and riders 18 years of age or younger. Nevertheless, our own data support national figures indicating that approximately 90% of motorcycle injuries and fatalities occur to persons over the age of 18. 8 In addition, states with partial hehnet laws report lower helmet usage rates among motorcyclists of all ages. 22 Finally, partial helmet laws are exceedingly difficult to enforce, requiring police to estimate, at a distance, the age of a person on a moving motorcycle. The high public cost of motorcycle injuries reported in this study and the well-documented increase in the number and severity of these injuries since repeal of motorcycle helmet laws 5-13 should give substantial impetus to advocates of full motorcycle helmet use laws in Connecticut. Using the National Highway Traffic Safety Administration formula and 1989 Connecticut Department of Transportation figures, a full-use helmet law would save an estimated ten lives and prevent more than 90 nonfatal injuries each year at an annual cost savings to the state of $5.1 million. 22 The failure of Connecticut to reinstate a motorcycle helmet law has created a tremendous financial burden for the state. Hospitals caring for patients with motorcycle injuries are at significant financial risk due to the high proportion of uninsured crash victims and the inadequate reimbursement of DRG-based systems.23,24 These data support other studies that indicate I~
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that a significant portion of the cost for motorcycle injuries requiring hospitalization is paid by the taxpayer.9 15 Furthermore, our cost estimate ($29 million) includes only the direct medical care costs generated by hospitalized motorcyclists; ED treatment, subsequent acute hospitalizations, follow-up care, long-term rehabilitation, disability, and lost productivity are not included and may be substantial.m,14, 25 This study is a population-based profile of motorcycle injuries and costs in Connecticut. The strengths of such a study lie in its ability to characterize and analyze a significant injury problem without the limitations inherent in evaluating the experiences of a single trauma center, which may not be representative of the population at risk, the scope of injuries, and the health care costs. We were able to calculate statewide mortality rates and estimate statewide hospitalization rates due to motorcycle injuries. We were also able to profile the type and severity of motorcycle-related injuries and estimate statewide direct medical care costs. Such data are crucial for health and public policy planners. Nevertheless, there remain several limitations to our data. Statewide mortality rates were calculated using Connecticut death certificate data. Although death certificate information has been considered the gold standard for mortality rate calculation, discrepancies in motorcycle-related deaths between death certificate data and police accident reports have been reported. Sosin et al reported a discrepancy of approximately 25% between the two data sources, resulting in an underestimation of motorcycle fatalities by death certificate records, r A preliminary review of our own data sources suggests that the discrepancy in Connecticut is much greater. During the study period, Connecticut death certificates from 1985 through 1987 identified 112 motorcycle fatalities compared with 214 motorcycle deaths reported by police accident reports. Further research is under way to determine the cause of this discrepancy. Our figures represent statewide estimations of nonfatal motorcycle injuries and costs. Estimation was necessary due to nonuniform recording of E-codes on hospital discharge records. Among Connecticut's 36 acute care hospitals, the percentage of hospital discharge records containing an E-code varied from 0.4% to 97.9%. In addition to the lack of unifmm reporting of E-codes on hospital discharge records, there is no uniform method for estimating statewide injury totals. Our method of analyzing data only from hospitals with m o I ~ than 70% of records containing E-codes was derived from unpublished reports; it has not been standardized. Given the wide variation in the use of E-codes, an agreed-on method for statewide injury total
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estimation must be adopted if more studies analyzing populationbased data are to be performed. Ahernatively, mandating the use of E-codes on hospital discharge and ED records would vastly improve the quality of infm~ation that could be retrieved from these sources. A third limitation of our data is the use of only hospital records to determine nonfatal motorcycle injury severity and cost. Although one can safely assume that the most severely injured motorcyclists are admitted to the hospital, the resulting injury profile excludes a large proportion of injured patients who are treated in the ED and released. Studies report that between one fourth and one half of injured motorcyclists require hospital admission.26, 2v Our study underestimates the impact of motorcycle injuries in Connecticut because the number and cost of treating injured motorcyclists who are not admitted to the hospital are not readily available. Bach and Wyman estimated that if only 10% of injured motorcyclists required hospitalization, the national costs of motorcycle injury- would be $263 millionJ ¢ One additional problem with motorcycle injury hospital discharge data in Connecticut is that helmet use is not included. Therefore, we were not able to compare injury severity or cost based on helmet use. Finally, a potential limitation to our study is the decision not to exclude nonresidents from the analysis of motorcycle-injured patients hospitalized in the state. We made the assumption that the number of nonresidents hospitalized in Connecticut was small and would approximate the number of Connecticut residents hospitalized outside the state; in effect the two groups would cancel each other out and provide a true population-based, nonfatal injury profile. This assumption held true for the largest major trauma center in the state, where more than 90% of motorcycle-injured patients were state residents. Therefore, we believe that our estimated rates for hospitalization due to motorcycle injuries reflect a population-based experience.
CONCLUSION Motorcycle crashes are an important cause of death and morbidity in Connecticut. The direct medical care costs associated with motorcycle crashes are high, and the hospitals caring for these patients are not reimbursed adequately. A significant proportion of fatal and serious nonfatal injuries results fiom head injury that can be prevented through use of motorcycle helmets. The information presented in this study should enhance legislative efforts to re-enact a full motorcycle helmet law in Connecticut. I
The authors thank Gene lnterlandi and Mario Tonarelli for their assistance in providing data from the Connecticut Departmen t of Transportation.
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I
REFERENCES
Address for reprints: Garry Lapidus, PA-C, MPH, Connecticut Childhood Injury
/. US Department of Transportation, National Highway Traffic Safety Administration: Fatal Accident Reporting System.Washington, DC, DOT.1989. 2. BaranchikJ, Chatterjee F, Greene-CraddenY, et ah Motor vehicle trauma in Northeastern Ohio: I. Incidence and outcome by age, sex, and road-use category. Am J Epidemiol 1986;123:846-861. 3. US Department of Transportation, National Highway Traffic Safety Administratian: General Estimates System 1989."A Review of Information on Police-Reported Traffic Crashesin the United States. Washington, DC, DOT, publication No. HS 807-665, December 1990. 4. Hurt, H, Ouelett J, Them D: Motorcycle Accident Causeand Factors and Identification of Countermeasures: Volume 1, TechnicalReport. Washington, DC, US Department of Transportation, National Highway Traffic Safety Administration, January 1981. 5. Bachulis B, Sangster W, Gorrell G, et al: Patterns of injury in helmeted and nonhelmeted motorcyclists. Am J Surg 1988;155:708-711. 8. Heiiman D, Weisbuch J, Blair R, eta/: Motorcycle-@ated trauma and helmet usage in North Dakota. Ann Emer9Mad 1982;11:659-664. 7. Sosin DM, SacksJ. Holmgreen P: Head-injury associated deaths from motorcycle crashes: Relationship te helmet-use laws. JAMA 1990;264:2395-2399. 8. US Department of Transportation, National Highway Traffic Safety Administration: The Effect of Helmet Law Repeal.Washington, DC, DOT publication No. HS 807-605, December 1986. 9. Watson G, Zader P, Wilks A: Helmet use, helmet-use laws, and motorcycle fatalities. Am J Public Health 1981;71:297-30g. 10. Rivara F. Dicker B, BergmanA, et al: The public cost of motorcycle trauma. JAMA 1988;260:221-223. 11. Muller A: Evaluation of the costs and benefits of motorcycle helmet laws. Am J Public Health 1980;78:586-592. 12. US Department of Transportation, National Highway Traffic Safety Administration: A Report to Congresson the Effect of Motorcycle Helmet Use Law RepeaI--A Case for Helmet Use. Washington, DC, DOT publication No. HS 805-312, April 1980. 13. McSwain N, Belles A: Motorcycle helmets--Medical costs and the law. J Trauma 1990;30:1189-1199. 14. Bach B, Wyman E: Financial charges of haspitalized motorcyclists at the Massachusetts General Hospital. J Trauma1986;26:343 347. 15. Bray T, SzaboR, Timmerman L, et al: Cost of orthopedic injuries sustained in motorcycle accidents. JAMA 1985;254:2452-2453. 16. Dried JM, CordascoFA, Volz RG: Medical and economic parameters of motorcycle-induced trauma. Clin OrthopRelat Res 1987;223:252-258. 17. The IntematienalClassification of Diseases, 9th Revision, ClinicalModification. Washington, DC, US Department of Health and Human Services, publication No. PHS 80 1260,1980. 18. State of Connecticut Office of Policy and Management: ConnecticutPopulation Projections. Hartford, Connecticut, Connecticut State Data Center, series 89.1, June 1989. 19. Motorcycle industry Council: 1990Motorcycle Statistical Annuah 1989Motorcycle Accident Statistics. Irvine, California, Motorcycle Industry Councit, 1990, p 38. 20. American Association for Automative Medicine: TheAbbreviated Injury Scale, 1990Revision. Des P]aines, Illinois, AAAM, 1990. 21. Benson L: Methods for Evaluating Injury Severity. New Haven, Connecticut,Yale University School of Public Health, 1991. Thesis. 22. US Department of Transportation, National Highway Traffic Safety Administration: A Model for Estimating the EconomicSavings from IncreasedMotorcycle Helmet Use. Washington, BC, DOT publication No. HS 807-251, March 1988. 23. Jacobs LM, Schwartz RJ: The impact ef prospective reimbursement on trauma centers. Arch Surg 1986;121:479-483. 24. Bennett DR, Jacebs LM, and Schwartz RJ: Incidence, costs, and DRG-basedreimbursement for traumatic brain injured patients: A 3-year experience. J Trauma1989;29:556-565. 25. Rice M, Mackenzie E, and Associates: Cost of Injury in the United States (a report to Congress).San Francisco,California, Institute for Health and Aging, University of California; Baltimore, Maryland, The Johns Hopkins University, 1989. 26. Haddad JP, EchaveV, Brown R, et al: Motorcycle accidents: A review of 77 patients treated in a three month period. J Trauma1978;16:550-556. 27. Najjar D: A ComprehensiveAnalysis of Motorcycle Accident Data. Washington, DC, National Center for Statistics and Analysis, September 1980.
Prevention Center, 80 Seymour Street, Hartford, Connecticut.
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