 |
|
Trends in Hospitalization Associated With Traumatic Brain Injury
David Thurman, MD, MPH;
Janet Guerrero, MS
JAMA. 1999;282:954-957.
ABSTRACT
| |
Context Traumatic brain injury (TBI) is associated with more than 50,000 deaths in the United States each year, and recent observations suggest a substantial decline in TBI-related hospitalizations and deaths.
Objective To analyze long-term trends in TBI-related hospitalization in the United States.
Design, Setting, and Participants Analysis of existing data from 1980 through 1995 from the National Hospital Discharge Survey, an annual survey representing the US general population. The number of participating hospitals ranged from 400 to 494.
Main Outcome Measures Annual rates of TBI-related hospitalization, stratified by age, sex, severity of injury, and outcome.
Results The annual number of TBI cases identified from the sample during the study period ranged from 1611 to 3129. Overall rates of hospitalization for TBI declined an estimated 51%, from 199 to 98 per 100,000 per year. When analyzed by severity of injury, mild TBIs declined most during this period, from 130 to 51 hospitalizations per 100,000 per year (61% decline; P<.001 compared with intermediate and severe TBI). The decline was greatest among those aged 5-14 years (-66%) and least among those aged 65 years or older (-9%). The ratio of male to female rates showed little variation during the study period (ratio, 1.8; 95% confidence interval [CI], 1.6-2.0), as did the in-hospital mortality rate (mean, 5.3 per 100,000; 95% CI, 3.6-7.1).
CONCLUSIONS Changes in hospital practices may be a major factor in the declining rates of TBI-related hospital admissions. These practices increasingly appear to exclude persons with less severe TBI from hospital admission and shift their care to outpatient settings.
INTRODUCTION
In the United States, traumatic brain injury (TBI) is associated with the death of 51,000 people each year, about one third of all injury deaths.1 Traumatic brain injury is a cause of long-term disability that annually affects an estimated 70,000 to 90,000 people.1-2 Given these serious consequences and the large number of people affected, public health efforts to prevent the occurrence and mitigate the consequences of TBI have received increased attention in recent years.3
Some success in TBI prevention and treatment efforts is suggested by an analysis of national mortality trends, which indicates a 22% decline in rates of death associated with TBI from 1979 to 1992.4 To our knowledge, there is no published study describing national trends in TBI-related hospitalizations over a comparable period, although comparisons of some studies in selected localities suggest the rate of these hospitalizations has declined more steeply.5 The purpose of this study is to describe long-term trends in TBI-associated hospitalization in the United States; to examine trends in the distribution of these injuries by age, sex, level of severity, and outcome; and to assess the implications of these trends with respect to public health and health care delivery.
METHODS
To estimate annual rates of TBI-associated hospitalization, we analyzed data collected from 1980 through 1995 by the National Hospital Discharge Survey6 of the Centers for Disease Control and Prevention National Center for Health Statistics. Each year during this interval, the number of hospitals participating in the survey ranged from 400 to 494, and the sample size ranged from 181,000 to 276,000 hospitalizations for all causes. From 1980 through 1995, the annual number of cases of TBI identified in the sample ranged from 1611 to 3129. These TBI cases were identified using the Centers for Disease Control and Prevention case definition,7 ie, all hospital discharge records that contained—in 1 or more of 7 diagnostic data fields—an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)8 diagnostic code in the ranges 800.0-801.9, 803.0-804.9, or 850.0-854.1. The National Hospital Discharge Survey used a multistage probability sampling design with weights applied to records to adjust for the probability of selection and nonresponse. These weighted records were used to generate US population estimates for the total number of hospitalizations associated with TBI each year. Relative SEs for annual population estimates, which ranged from 5% to 8%, were calculated using methods described by the National Center for Health Statistics.6
To classify the severity of TBIs among patients who were hospitalized, we used ICDMAP-90,9 a computer algorithm that maps ICD-9-CM diagnostic codes to a 6-level score approximating the Abbreviated Injury Scale (ICD/AIS).10 We then reclassified the ICD/AIS scores for the head region to a 3-level scale: ICD/AIS scores of 1 or 2 were defined as mild, 3 as moderate, and 4 through 6 as severe. We could not perform an extensive analysis of TBI incidence by cause of injury, because such data were incomplete; ICD-9-CM external-cause-of-injury codes (E codes) were present in only 10% to 47% of cases during the period of this study.
We used commercially available statistical software to calculate crude hospitalization incidence rates for each year, using as denominators the US Census estimates for the national civilian population at midyears during this interval. Generalized variance estimation functions that were provided by the National Center for Health Statistics were used to generate confidence intervals (CIs) for rates. Estimated crude hospitalization incidence rates by outcome status, injury severity, sex, and age by year, as well as average rates for the entire time interval, are presented. We compared 2-year aggregate data from 1980-1981 and 1994-1995 to measure changes between end points of the entire time interval, using z scores to test for differences in rates. To test for differences in percent change of hospitalization rates between categories of TBI severity, we calculated z scores using variance approximation methods.11
To compare estimated rates of TBI-associated hospitalization with TBI-associated emergency department (ED) visits, we used data collected by the National Hospital Ambulatory Medical Care Survey from 1992 (the first year of the survey) to 1995.12 Because the variance estimates associated with individual years of the survey were large, we calculated the average annual rate of TBI-associated ED visits for the interval 1992 to 1995 using methods described elsewhere.13 As with the analysis of National Hospital Discharge Survey data, TBI cases were identified among National Hospital Ambulatory Medical Care Survey records by searching all 3 diagnostic fields for ICD-9-CM codes consistent with the Centers for Disease Control and Prevention case definition. Traumatic brain injury–associated ED visits in 1995 that included a computed tomography (CT) scan evaluation of any body region were identified by the presence of a CT procedure code in the case record. Our analyses of National Hospital Ambulatory Medical Care Survey data included only those TBI-associated ED visits that did not lead to hospital admission or death.
RESULTS
From 1980 to 1995, the estimated annual incidence rate of hospitalization associated with TBI declined 51%, from 199 to 98 per 100,000 people (Table 1 and Figure 1). The rates for males, which peaked at 260 per 100,000 in 1981, were consistently higher than the rates for females over the entire time interval. The average ratio of male-to-female rates was 1.8 (95% CI, 1.6-2.0), showing little variation during this time. The in-hospital mortality rate also showed little change during this period (Figure 1), with a mean of 5.3 (95% CI, 3.6-7.1) deaths per 100,000. External cause of injury was identified in 27% of TBI-related hospitalizations during this interval; 13% of injuries were attributed to motor vehicle crashes, 7% to falls, and 7% to all other known causes.
|
|
|
|
Table. Aggregate Incidence of TBI-Related Hospitalization by Outcome, Injury Severity, Sex, and Age, 1980-1981 vs 1994-1995*
|
|
|
|
|
|
|
Figure 1. Incidence Rates of TBI-Related Hospitalization in the United States, 1980-1995
Data are from National Hospital Discharge Survey, National Center for Health Statistics, Centers for Disease Control and Prevention. TBI indicates traumatic brain injury. The shaded areas represent 95% confidence intervals.
|
|
|
The decline in rates of TBI-related hospitalization varied among different age groups (Table 1). The decline was greatest among persons 5 to 14 years old and least among persons 65 years old or older.
The incidence rate of hospitalization for mild TBI declined significantly (P<.001) compared with the rates of hospitalization for moderate and severe TBI (Table 1 and Figure 2). From 1980 to 1995, TBIs classified as mild declined 61%, from 130 to 51 hospitalizations per 100,000 people, TBIs classified as moderate declined 19%, from 26 to 21 hospitalizations per 100,000, and TBIs classified as severe increased 90%, from 10 to 19 hospitalizations per 100,000. In 1995, the total number of hospitalizations for TBI was estimated at approximately 260,000.
|
|
|
|
Figure 2. Incidence Rates of TBI-Related Hospitalization in the United States by Category of Severity, 1980-1995
Data are from National Hospital Discharge Survey, National Center for Health Statistics, Centers for Disease Control and Prevention. TBI indicates traumatic brain injury. The shaded areas represent 95% confidence intervals.
|
|
|
For 1992 to 1995, the estimated annual rate of TBI-related visits to hospital EDs was 394 (95% CI, 357-430) per 100,000 people. Among all TBI-associated ED visits in 1995, the proportion that included a CT scan evaluation was 26%. Among ED visits in 1995 that were associated with TBI without diagnosis of injury to other body regions, 27% included a CT scan evaluation.
COMMENT
Several factors could account for the major decline in the estimated national rate of hospitalizations for TBI during the 16 years of the study period. First, during almost the same interval (1979-1992), the TBI-associated death rate decreased from 24.6 per 100,000 people to 19.3 per 100,000, a development that has been attributed in part to successes in injury prevention, especially those associated with motor vehicles.4 In our study, because external cause of injury was not consistently available in the National Hospital Discharge Survey data, we cannot directly assess any effects of injury prevention on trends in TBI-related hospitalizations during the study interval. Nevertheless, if success in injury prevention were the only factor contributing to the decrease in TBI-related hospitalization, then we would expect the decreases in rates of TBI-related hospitalization and TBI-related death to be similar in proportion; we might also expect a similar decrease in TBI-related hospitalization rates among all levels of injury severity. However, in contrast to the 22% decline in the TBI-associated death rate between 1979 and 1992, our data demonstrate a disproportionately greater decline in TBI-related hospitalization rates—51% during the interval of this study—with the decline found mainly among injuries of mild severity. Second, in the United States from 1980 to 1994, the rate of hospitalization for all causes declined 29%, suggesting a change in hospital practices for admissions.14 In a study of hospital service utilization and expenditures during this period, a reduction in inpatient services was associated with an increase in outpatient services, a shift attributed to the growing influence of prospective payment system reimbursement and managed care.15 Thus, hospital admission policies may now exclude a larger proportion of patients with mild TBI.
Hospital admission practices for TBI also may be affected by improved diagnostic technology. More frequent ED-based CT scanning may shift treatment of milder TBIs from hospital inpatient services to outpatient services. However, this effect may be limited, since only 26% of ED visits for TBI in 1995 included CT scan evaluations. A shift in TBI care toward the ED cannot be measured directly, because we are unable to compare rates of TBI-related ED visits with rates of TBI-related hospital admissions throughout the study period. However, the estimated rate of TBI-related ED visits in 1992 through 1995—approximately 1 million cases each year in the United States—indicates that about 80% of persons now evaluated for TBI are not admitted to hospitals.
The increased rate of TBIs classified as severe runs counter to all other trends found in these data. Three factors might account for this phenomenon. The increased number of cases classified as severe may be influenced by changes in ICD-9-CM coding practices during this period that decreased the assignment of nonspecific codes and increased the assignment of codes with specific severity information. Also, increased reliance on CT scanning and improved imaging during this study period may have increased the detection of trauma-related intracranial lesions, again leading to the assignment of more specific ICD-9-CM codes that indicate greater severity. In addition, improvements in trauma care during the interval of this study may have increased the proportion of critically injured persons who survive long enough to be admitted to hospitals, thereby increasing the number of cases classified as severe.
Our analysis has several limitations. The accuracy of our estimate of trends in the TBI severity distribution depends on correct ICD-9-CM diagnostic coding that is consistent over time among all hospitals in the sample. Limitations in the accuracy of diagnostic coding performed in hospitals have been noted since the beginning of this study period.16 Furthermore, coincident with the increased use of prospective payment systems, coding practices appear to have evolved toward increased use of codes denoting more specific and severe diagnostic categories.17-19 However, changes in coding practices documented during this period do not appear sufficient to account for the very large decline in rates of hospitalizations for TBIs classified as mild.
The accuracy of our estimate of trends in the TBI severity distribution also depends on the accurate classification of these injuries by ICDMAP-90 software. Misclassification of these data would affect our estimated relative proportions of TBI by level of severity more than the trends for each level of severity, because this classification algorithm is applied consistently to the data across all years examined.
CONCLUSION
Despite a substantial overall reduction of TBI-related hospitalization rates between 1980 and 1995, TBI continues to represent a major public health problem that calls for the application of more effective methods of injury prevention. The shift toward treating persons with less severe TBI as outpatients raises additional concerns. The proportion of those with mild TBI who experience effects later is unknown, although cognitive and emotional sequelae resulting in extended or long-term disability have been reported in a minority of cases.20-24 Our data provide no information about the number of persons seen in EDs or other outpatient facilities with such sequelae who may need follow-up care or evaluation. Assessing these needs and ensuring the availability of appropriate services is an important function of public health; additional studies are needed to address these issues.
AUTHOR INFORMATION
Corresponding Author and Reprints: David J. Thurman, MD, MPH, CDC National Center for Injury Prevention and Control, Mailstop F-41, 4770 Buford Hwy, NE, Atlanta, GA 30341-3724 (e-mail: dxt9{at}cdc.gov).
Author Affiliations: National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, Ga.
REFERENCES
| |
1. Thurman DJ, Alverson C, Dunn KA, et al. Traumatic brain injury in the United States: a public health perspective. J Head Trauma Rehabil. In press.
2. Federal Interagency Head Injury Task Force Report. Washington, DC: US Dept of Health and Human Services; 1989.
3. Kraus JF, McArthur DL. Epidemiologic aspects of brain injury. Neurol Clin. 1996;14:435-450.
FULL TEXT
|
ISI
| PUBMED
4. Sosin DM, Sniezek JE, Waxweiler RJ. Trends in death associated with traumatic brain injury, 1979 through 1992: success and failure. JAMA. 1995;273:1778-1780.
FREE FULL TEXT
5. Centers for Disease Control and Prevention. Traumatic brain injury, Colorado, Missouri, Oklahoma, and Utah—1990-1993. MMWR Morb Mortal Wkly Rep. 1997;46:8-11.
PUBMED
6. Data File Documentation, National Hospital Discharge Survey, 1980-1995. Rockville, Md: National Center for Health Statistics, Centers for Disease Control and Prevention; 1997.
7. Thurman DJ, Sniezek JE, Johnson D, Greenspan A, Smith SM. Guidelines for Surveillance of Central Nervous System Injury. Atlanta, Ga: Centers for Disease Control and Prevention; 1995.
8. International Classification of Diseases, Ninth Revision, Clinical Modification. 6th ed. Washington, DC: US Dept of Health and Human Services; 1996.
9. Center for Injury Research and Policy of The Johns Hopkins University School of Public Health. ICDMAP-90 Software. Baltimore, Md: The Johns Hopkins University and Tri-Analytics Inc; 1997.
10. The Abbreviated Injury Scale. Rev ed. Des Plaines, Ill: Association for the Advancement of Automotive Medicine; 1990.
11. Kish L. Survey Sampling. New York, NY: John Wiley & Sons; 1965:206-210.
12. Data File Documentation, National Hospital Ambulatory Medical Care Survey, 1995. Rockville, Md: National Center for Health Statistics, Centers for Disease Control and Prevention; 1997.
13. Burt CW, Fingerhut LA. Injury visits to hospital emergency departments: United States 1992-95. Vital Health Stat 13. 1998;131:1-76.
14. Graves EJ, Gillum BS. National Hospital Discharge Survey: annual summary, 1994. Vital Health Stat 13. 1997;128:i-v,1-50.
15. Robinson JC. Decline in hospital utilization and cost inflation under managed care in California. JAMA. 1996;276:1060-1064.
FREE FULL TEXT
16. Hsia DC, Krushat WM, Fagan AB, Tebbutt JA, Kusserow RP. Accuracy of diagnostic coding for Medicare patients under the prospective-payment system. N Engl J Med. 1988;318:352-355.
ABSTRACT
17. Goldfarb MG, Coffey RM. Change in the Medicare case-mix index in the 1980s and the effect of the prospective payment system. Health Serv Res. 1992;27:385-415.
ISI
| PUBMED
18. Hsia DC, Ahern CA, Ritchie BP, Moscoe LM, Krushat WM. Medicare reimbursement accuracy under the prospective payment system, 1985 to 1988. JAMA. 1992;268:896-899.
FREE FULL TEXT
19. Assaf AR, Lapane KL, McKenney JL, Carleton RA. Possible influence of the prospective payment system on the assignment of discharge diagnoses for coronary heart disease. N Engl J Med. 1993;329:931-935.
FREE FULL TEXT
20. Rimel RW, Giordani B, Barth JT, Boll TJ, Jane JA. Disability caused by minor head injury. Neurosurgery. 1981;9:221-228.
ISI
| PUBMED
21. Gronwall D. Cumulative and persisting effects of concussion on attention and cognition. In: Levin HS, Eisenberg HM, Benton AL, eds. Mild Head Injury. New York, NY: Oxford University Press; 1989:153-175.
22. Ruff RM, Levin HS, Mattis S, et al. Recovery of memory after mild head injury: a three center study. In: Levin HS, Eisenberg HM, Benton AL, eds. Mild Head Injury. New York, NY: Oxford University Press; 1989:176-188.
23. McAllister TW. Neuropsychiatric sequelae of head injuries. Psychiatr Clin North Am. 1992;15:395-413.
ISI
| PUBMED
24. Macciocchi SN, Reid DB, Barth JT. Disability following head injury. Curr Opin Neurol. 1993;6:773-777.
ISI
| PUBMED
 CiteULike  Connotea  Del.icio.us  Digg  Reddit  Technorati  Twitter
What's this?
RELATED ARTICLES
September 8, 1999
JAMA. 1999;282(10):1007-1008.
EXTRACT
| FULL TEXT
Traumatic Brain Injury in High School Athletes
John W. Powell and Kim D. Barber-Foss
JAMA. 1999;282(10):958-963.
ABSTRACT
| FULL TEXT
Relationship Between Concussion and Neuropsychological Performance in College Football Players
Michael W. Collins, Scott H. Grindel, Mark R. Lovell, Duane E. Dede, David J. Moser, Benjamin R. Phalin, Sally Nogle, Michael Wasik, David Cordry, Michelle Klotz Daugherty, Samuel F. Sears, Guy Nicolette, Peter Indelicato, and Douglas B. McKeag
JAMA. 1999;282(10):964-970.
ABSTRACT
| FULL TEXT
Neuropsychological Impairment in Amateur Soccer Players
Erik J. T. Matser, Alphons G. Kessels, Muriel D. Lezak, Barry D. Jordan, and Jaap Troost
JAMA. 1999;282(10):971-973.
ABSTRACT
| FULL TEXT
Rehabilitation of Persons With Traumatic Brain Injury
NIH Consensus Development Panel on Rehabilitation of Persons With Traumatic Brain Injury
JAMA. 1999;282(10):974-983.
ABSTRACT
| FULL TEXT
Traumatic Brain Injury and Concussion in Sports
James P. Kelly
JAMA. 1999;282(10):989-991.
EXTRACT
| FULL TEXT
THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES
|
A Reference Standard Bibliography: Music Therapy With Children Who Have Experienced Traumatic Brain Injury
Gilbertson
Music and Medicine 2009;1:129-139.
ABSTRACT
| FULL TEXT
Depression and Cognitive Complaints Following Mild Traumatic Brain Injury
Silver et al.
Am. J. Psychiatry 2009;166:653-661.
ABSTRACT
| FULL TEXT
Trends in Hospitalizations Associated With Pediatric Traumatic Brain Injuries
Bowman et al.
Pediatrics 2008;122:988-993.
ABSTRACT
| FULL TEXT
Pediatric Traumatic Brain Injury Is Inconsistently Regionalized in the United States
Hartman et al.
Pediatrics 2008;122:e172-e180.
ABSTRACT
| FULL TEXT
REMARKABLE DECLINE IN HIP FRACTURE INCIDENCE IN YOUNGER AGE GROUPS IN GERMANY
Icks et al.
AJPH 2007;97:1733-1734.
FULL TEXT
Overlooked But Critical: Traumatic Brain Injury as a Consequence of Interpersonal Violence
Banks
Trauma Violence Abuse 2007;8:290-298.
ABSTRACT
How common are the "common" neurologic disorders?
Hirtz et al.
Neurology 2007;68:326-337.
ABSTRACT
| FULL TEXT
Diagnostic Imaging of Traumatic Brain Injury.
FURLOW
radtech 2006;78:145-156.
ABSTRACT
| FULL TEXT
Sex differences in baseline neuropsychological function and concussion symptoms of collegiate athletes * Commentary * Commentary
Covassin et al.
Br. J. Sports. Med. 2006;40:923-927.
ABSTRACT
| FULL TEXT
Considerations in Fluids and Electrolytes After Traumatic Brain Injury
Rhoney and Parker
Nutr Clin Pract 2006;21:462-478.
ABSTRACT
| FULL TEXT
Medical outcome after immediate computed tomography or admission for observation in patients with mild head injury: randomised controlled trial
Geijerstam et al.
BMJ 2006;333:465.
ABSTRACT
| FULL TEXT
Incidence of Pediatric Traumatic Brain Injury and Associated Hospital Resource Utilization in the United States
Schneier et al.
Pediatrics 2006;118:483-492.
ABSTRACT
| FULL TEXT
An epidemiological study of head injuries in a UK population attending an emergency department
Yates et al.
J. Neurol. Neurosurg. Psychiatry 2006;77:699-701.
ABSTRACT
| FULL TEXT
Incidence Rates of Hospitalization Related to Traumatic Brain Injury--12 States, 2002
JAMA 2006;295:1764-1765.
FULL TEXT
Prevalence of anterior pituitary insufficiency 3 and 12 months after traumatic brain injury
Schneider et al.
Eur J Endocrinol 2006;154:259-265.
ABSTRACT
| FULL TEXT
Trends in Diagnosis Rates for Autism and ADHD at Hospital Discharge in the Context of Other Psychiatric Diagnoses
Mandell et al.
Psychiatr. Serv. 2005;56:56-62.
ABSTRACT
| FULL TEXT
Reporting of the incidence of hospitalised injuries: numerator issues
Boufous and Williamson
Inj. Prev. 2003;9:370-375.
ABSTRACT
| FULL TEXT
Acute Effects and Recovery Time Following Concussion in Collegiate Football Players: The NCAA Concussion Study
McCrea et al.
JAMA 2003;290:2556-2563.
ABSTRACT
| FULL TEXT
Trends in hospitalization after injury: older women are displacing young men
Shinoda-Tagawa and Clark
Inj. Prev. 2003;9:214-219.
ABSTRACT
| FULL TEXT
Mild Traumatic Brain Injury and Psychiatric Disorders
Mateo and Glod
J Am Psychiatr Nurses Assoc 2003;9:129-133.
ABSTRACT
Injury Surveillance
Horan and Mallonee
Epidemiol Rev 2003;25:24-42.
FULL TEXT
Prolonged Therapeutic Hypothermia After Traumatic Brain Injury in Adults: A Systematic Review
McIntyre et al.
JAMA 2003;289:2992-2999.
ABSTRACT
| FULL TEXT
Clinical Correlates of Aggressive Behavior After Traumatic Brain Injury
Tateno et al.
J. Neuropsychiatry Clin. Neurosi. 2003;15:155-160.
ABSTRACT
| FULL TEXT
Practice parameter: Antiepileptic drug prophylaxis in severe traumatic brain injury: Report of the Quality Standards Subcommittee of the American Academy of Neurology
Chang and Lowenstein
Neurology 2003;60:10-16.
ABSTRACT
| FULL TEXT
Repeated mild injury causes cumulative damage to hippocampal cells
Slemmer et al.
Brain 2002;125:2699-2709.
ABSTRACT
| FULL TEXT
Management of Head Trauma*
Marik et al.
Chest 2002;122:699-711.
ABSTRACT
| FULL TEXT
Traumatic Brain Injury Among American Indians/Alaska Natives--United States, 1992-1996
JAMA 2002;288:37-38.
FULL TEXT
The impact of face shield use on concussions in ice hockey: a multivariate analysis
Benson et al.
Br. J. Sports. Med. 2002;36:27-32.
ABSTRACT
| FULL TEXT
The Epidemiology of Pediatric Traumatic Brain Injury in Minnesota
Reid et al.
Arch Pediatr Adolesc Med 2001;155:784-789.
ABSTRACT
| FULL TEXT
Validation of the ICD/AIS MAP for pediatric use
Durbin et al.
Inj. Prev. 2001;7:96-99.
ABSTRACT
| FULL TEXT
National estimates of non-fatal firearm related injuries other than gunshot wounds
Hootman et al.
Inj. Prev. 2000;6:268-274.
ABSTRACT
| FULL TEXT
Hospitalizations for Minor Traumatic Brain Injury Decline
JWatch Emergency Med. 1999;1999:5-5.
FULL TEXT
Traumatic Brain Injury and Concussion in Sports
Kelly
JAMA 1999;282:989-991.
FULL TEXT
|
