Traumatic brain injury (TBI) is defined by the Centers for Disease Control and Prevention (CDC) as an injury to the head resulting from blunt or penetrating trauma or from acceleration-deceleration of force causing neurological or neuropsychological abnormalities, such as altered level of consciousness, intracranial lesion, memory loss, skull fracture, or death [
TBI-related direct and indirect costs, including medical costs and loss of productivity, totaled an estimated $60 billion in the United States, annually [
Our study aim is to examine sociodemographic variables related to TBI-H, TBI-related causes (TBI-C), and TBI-M in California. Based on the existing literature, we hypothesize that there will be a statistically significant age, gender, and racial differences with respect to TBI-H, TBI-C, and TBI-M. Findings from this study can inform health policy makers and health promotion programmers to identify populations at greater risk of TBI-H and TBI-M in California. In addition, identifying sociodemographic disparities in the experience of TBI can inform practitioners, prevention planners, educators, and service sectors who aim to reduce the burden of TBI in their community.
This was a cross-sectional study of data obtained from the Office of Statewide Health Planning and Development (OSHPD), a database that contains a summary of all the inpatient hospital discharges in California and is used for billing and payment services. For this study we used California hospital discharge data for 2001–2009 (See Figure
Traumatic brain injury related hospitalization and mortality in california.
We used the International Classification of Diseases, 9th Revision, and Clinical Modification (ICD-9-CM) to identify TBI-H (Table
International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) for identification of TBI-H, TBI-M, and TBI-.
TBI-H | TBI-M | TBI-C | TBI-C | TBI-C | TBI-C |
---|---|---|---|---|---|
(ICD-9-CM): |
ICD-10-CM |
Motor vehicle accidents: |
Falls: |
Assault: |
Struck by & struck against: including homicide and injury purposely inflicted by another person: E916, E917 |
Age in years was included as 11 groups (0–4, 5–9, 10–14, 15–19, 20–24, 25–34, 35–44, 45–54, 55–64, 65–74, and
All analyses were obtained using Statistical Analysis Software, SAS version 9.3. We used frequency (count and percentage) to depict the overall characteristics of the sample for the categorical variables (age, sex, race/ethnicity, insurance status, length of hospital stay, and years of admission). We conducted bivariate analysis using the chi square test to determine the statistical difference in the outcome variables (TBI-H and TBI-M) by the main independent variable (TBI-C) and the other independent variables (age, gender, race/ethnicity, length of stay, severity, insurance status, and admission year). We used unadjusted logistic regressions to determine the association between each independent variable and the TBI-M. In addition, we performed multiple logistic regression to test the independent association between study predictor variables and TBI-M while controlling for the other variables in the model (i.e., age, gender, race/ethnicity, admission year, length of stay, insurance status, and severity). Unadjusted and adjusted odds ratios and 95% confidence intervals (CIs) are presented, and statistical significance is considered at
The study included 61,188 hospital admissions. The average age of the population was 54.9 years, and standard deviation was 27.5 years. Table
Estimated numbers and percentages of traumatic brain injury related hospitalization in California categorized by causes, demographics, insurance, years of admission, and mortality, 2001–2009.
Patient characteristics | Number (percentage) |
---|---|
Causes | |
Motor vehicle | 11996 (19.6) |
Fall | 19113 (31.2) |
Assault | 6291 (10.3) |
Struck by | 300 (0.5) |
Other | 23488 (38.4) |
Age | |
0–4 | 3910 (6.4) |
5–9 | 760 (1.2) |
10–14 | 916 (1.5) |
15–19 | 2986 (4.9) |
20–24 | 3256 (5.3) |
25–34 | 4319 (7.1) |
35–44 | 5296 (8.7) |
45–54 | 6580 (10.8) |
55–64 | 4923 (8.1) |
65–74 | 5488 (9.0) |
≥75 | 22754 (37.2) |
Gender | |
Female | 25159 (41.1) |
Male | 36029 (58.9) |
Race | |
Blacks | 3407 (5.6) |
Hispanics | 13231 (21.6) |
Asians | 3317 (5.4) |
Other | 1001 (1.6) |
Whites | 40232 (65.8) |
Insurance | |
Medicare | 26942 (44.0) |
Medicaid | 9556 (15.6) |
Private | 13666 (22.3) |
Other | 10128 (16.6) |
Workers comp | 896 (1.5) |
Admission year | |
2001 | 6296 (10.3) |
2002 | 6740 (11.0) |
2003 | 7135 (11.7) |
2004 | 7306 (11.9) |
2005 | 7617 (12.5) |
2006 | 7589 (12.4) |
2007 | 7952 (13.0) |
2008 | 5088 (8.2) |
2009 | 5442 (8.9) |
Length of stay | |
1-2 | 25878 (42.3) |
3–5 | 16814 (27.5) |
6 or more | 18496 (30.2) |
Severity | |
Minor | 8933 (14.7) |
Moderate | 12341 (20.2) |
Serious | 18752 (30.7) |
Severe | 19649 (32.2) |
Critical | 1320 (2.2) |
Mortality | |
Alive | 56479 (92.3) |
Died | 4709 (7.7) |
Table
Estimated numbers and percentages of traumatic brain injury-related hospitalizations categorized by external causes and demographics, insurance, admission year, and procedure day in California, 2001–2009.
Motor vehicle | Fall | Assault | Struck by | Other |
|
|
---|---|---|---|---|---|---|
Age | ||||||
0–4 | 455 (11.6) | 2093 (53.5) | 322 (8.2) | 82 (2.1) | 958 (24.5) | <0.0001 |
5–9 | 264 (34.7) | 236 (31.1) | 6 (0.8) | 20 (2.6) | 234 (30.8) | |
10–14 | 313 (34.2) | 182 (19.9) | 48 (5.2) | 8 (0.9) | 365 (39.9) | |
15–19 | 1454 (48.7) | 284 (9.5) | 573 (19.2) | 7 (0.2) | 668 (22.4) | |
20–24 | 1582 (48.6) | 269 (8.3) | 824 (25.3) | 13 (0.4) | 568 (17.4) | |
25–34 | 1798 (41.6) | 435 (10.1) | 1173 (27.2) | 31 (0.7) | 882 (20.4) | |
35–44 | 1688 (31.9) | 794 (15.0) | 1285 (24.3) | 32 (0.6) | 1497 (28.3) | |
45–54 | 1631 (24.8) | 1289 (19.6) | 1279 (19.4) | 24 (0.4) | 2357 (35.8) | |
55–64 | 994 (20.2) | 1431 (29.1) | 474 (9.6) | 22 (0.5) | 2002 (40.7) | |
65–74 | 719 (13.1) | 2081 (37.9) | 140 (2.6) | 21 (0.4) | 2527 (46.1) | |
≥75 | 1098 (4.8) | 10019 (44.0) | 167 (0.7) | 40 (0.2) | 11430 (50.2) | |
Gender | ||||||
Female | 4507 (17.9) | 9356 (37.2) | 872 (3.5) | 94 (0.4) | 10330 (41.1) | <0.0001 |
Male | 7489 (20.8) | 9757 (27.1) | 5419 (15.0) | 206 (0.6) | 13158 (36.5) | |
Race | ||||||
Blacks | 725 (21.3) | 672 (19.7) | 987 (29.0) | 22 (0.7) | 1001 (29.4) | <0.0001 |
Hispanics | 3672 (27.8) | 3274 (24.7) | 2508 (19.0) | 117 (0.9) | 3660 (27.7) | |
Asians | 476 (14.4) | 1086 (32.7) | 134 (4.0) | 21 (0.6) | 1600 (48.2) | |
Other | 302 (30.2) | 265 (26.5) | 114 (11.4) | 4 (0.4) | 316 (31.6) | |
Whites | 6821 (17.0) | 13816 (34.3) | 2548 (6.3) | 136 (0.3) | 16911 (42.0) | |
Insurance | ||||||
Medicare | 1582 (5.9) | 11469 (42.6) | 482 (1.8) | 56 (0.2) | 13353 (49.6) | <0.0001 |
Medicaid | 2703 (28.3) | 2374 (24.8) | 1697 (17.8) | 71 (0.7) | 2711 (28.4) | |
Private | 4325 (31.7) | 3498 (25.6) | 1057 (7.7) | 81 (0.6) | 4705 (34.4) | |
Other | 3193 (31.5) | 1403 (13.9) | 3007 (29.7) | 42 (0.4) | 2483 (24.5) | |
Workers comp | 193 (21.5) | 369 (41.2) | 48 (5.4) | 50 (5.6) | 236 (26.3) | |
Length of stay | ||||||
1-2 | 5584 (46.6) | 8200 (42.9) | 3320 (52.8) | 159 (53) | 8615 (36.7) | <0.001 |
3–5 | 2595 (21.6) | 5679 (29.7) | 1402 (22.3) | 68 (22.7) | 7070 (30.1) | |
6 or more | 3817 (31.8) | 5234 (27.4) | 1569 (24.9) | 73 (24.3) | 7803 (33.2) | |
Severity | ||||||
Minor | 2162 (18.0) | 2612 (13.7) | 1159 (18.9) | 51 (17.0) | 2949 (12.6) | <0.0001 |
Moderate | 3746 (31.2) | 3641 (19.1) | 1279 (20.8) | 96 (32.0) | 3579 (15.3) | |
Serious | 4108 (34.2) | 5869 (30.7) | 2209 (36.0) | 104 (34.7) | 6462 (27.6) | |
Severe | 1749 (14.6) | 6701 (35.1) | 1296 (21.1) | 47 (15.7) | 9856 (42.0) | |
Critical | 231 (1.9) | 287 (1.5) | 201 (3.3) | 2 (0.7) | 599 (2.5) | |
Admission year | ||||||
2001 | 1398 (22.2) | 2859 (45.4) | 662 (10.5) | 42 (0.7) | 1335 (21.2) | <0.0001 |
2002 | 1484 (22.0) | 1977 (29.3) | 720 (10.7) | 32 (0.5) | 2527 (37.5) | |
2003 | 1571 (22.0) | 2158 (30.3) | 682 (9.6) | 38 (0.5) | 2686 (38.7) | |
2004 | 1575 (21.6) | 2133 (29.2) | 725 (9.9) | 29 (0.4) | 2844 (38.9) | |
2005 | 1418 (18.6) | 2137 (28.1) | 865 (11.4) | 40 (0.5) | 3157 (41.5) | |
2006 | 1460 (19.2) | 2275 (30.0) | 795 (10.5) | 47 (0.6) | 3012 (39.7) | |
2007 | 1334 (16.8) | 2433 (30.6) | 774 (9.7) | 26 (0.3) | 3385 (42.6) | |
2008 | 884 (17.4) | 1494 (29.4) | 499 (9.8) | 27 (0.5) | 2184 (42.9) | |
2009 | 869 (16.0) | 1640 (30.1) | 568 (10.4) | 19 (0.4) | 2346 (43.1) |
Table
Estimated number, percentages, unadjusted and adjusted odds ratio, and 95% confidence interval of traumatic brain injury related mortality in California, 2001–2009.
Mortality | Unadjusted | Adjusted | ||||
---|---|---|---|---|---|---|
Died | Alive | Odds ratio | 95% CI | Odds ratio | 95% CI | |
Causes | ||||||
Motor v. accident | 726 (6.1) | 11270 (93.9) | 0.612 | 0.561–0.667 | 1.270 | 1.140–1.415 |
Fall | 1342 (7.0) | 17771 (93.0) | 0.717 | 0.669–0.770 | 0.775 | 0.716–0.839 |
Assault | 397 (6.3) | 5894 (93.7) | 0.640 | 0.573–0.715 | 0.816 | 0.706–0.943 |
Other | 2237 (9.5) | 21251 (90.5) | 0.227 | 0.107–0.481 | 0.510 | 0.232–1.121 |
Struck by | 7 (2.3) | 293 (97.7) | Reference | Reference | Reference | Reference |
Age | ||||||
0–4 | 93 (2.4) | 3817 (97.6) | 0.199 | 0.162–0.246 | 0.156 | 0.119–0.204 |
5–9 | 16 (2.1) | 744 (97.9) | 0.176 | 0.107–0.289 | 0.147 | 0.086–0.253 |
10–14 | 19 (2.1) | 897 (97.9) | 0.173 | 0.110–0.273 | 0.121 | 0.073–0.198 |
15–19 | 198 (6.6) | 2788 (93.4) | 0.581 | 0.500–0.675 | 0.415 | 0.336–0.512 |
20–24 | 201 (6.2) | 3055 (93.8) | 0.538 | 0.464–0.624 | 0.420 | 0.340–0.518 |
25–34 | 198 (4.6) | 4121 (95.4) | 0.393 | 0.339–0.456 | 0.333 | 0.271–0.409 |
35–44 | 260 (4.9) | 5036 (95.1) | 0.422 | 0.370–0.482 | 0.398 | 0.331–0.478 |
45–54 | 413 (6.3) | 6167 (93.7) | 0.548 | 0.492–0.610 | 0.461 | 0.395–0.540 |
55–64 | 385 (7.8) | 4538 (92.2) | 0.694 | 0.620–0.776 | 0.625 | 0.538–0.726 |
65–74 | 447 (8.2) | 5041 (91.8) | 0.725 | 0.653–0.806 | 0.627 | 0.558–0.704 |
≥75 | 2479 (10.9) | 20275 (89.1) | Reference | Reference | Reference | Reference |
Gender | ||||||
Female | 1772 (7.0) | 23387 (93.0) | Reference | Reference | Reference | Reference |
Male | 2937 (8.2) | 33092 (91.8) | 1.171 |
1.102–1.245 |
1.36 |
1.27–1.46 |
Race | ||||||
Blacks | 253 (7.4) | 3154 (92.6) | 0.879 | 0.769–1.003 | 1.102 | 0.945–1.285 |
Hispanics | 777 (5.9) | 12454 (94.1) | 0.683 | 0.630–0.741 | 0.891 | 0.805–0.985 |
Asians | 269 (8.1) | 3048 (91.9) | 0.967 | 0.849–1.100 | 0.793 | 0.689–0.912 |
Other | 44 (4.4) | 957 (95.6) | 0.504 | 0.371–0.683 | 0.723 | 0.516–1.015 |
Whites | 3366 (8.4) | 36866 (91.6) | Reference | Reference | Reference | Reference |
Insurance | ||||||
Medicare | 2749 (10.2) | 24193 (89.8) | Reference | Reference | Reference | Reference |
Medicaid | 723 (7.6) | 8833 (92.4) | 0.720 | 0.661–0.784 | 1.518 | 1.318–1.748 |
Private | 703 (5.1) | 12963 (94.9) | 0.477 | 0.438–0.520 | 0.767 | 0.677–0.869 |
Other | 488 (4.8) | 9640 (95.2) | 0.446 | 0.403–0.492 | 0.827 | 0.707–0.966 |
Workers comp | 46 (5.1) | 850 (94.9) | 0.476 | 0.353–0.642 | 0.848 | 0.604–1.192 |
Severity | ||||||
Minor | 40 (0.4) | 8893 (99.6) | Reference | Reference | Reference | Reference |
Moderate | 117 (0.9) | 12224 (99.1) | 2.128 | 1.485–3.050 | 2.561 | 1.785–3.67 |
Serious | 1639 (8.7) | 17113 (91.3) | 21.29 | 15.54–29.17 | 30.652 | 22.34–42.06 |
Severe | 1991 (10.1) | 17658 (89.9) | 25.07 | 18.31– 34.32 | 31.456 | 22.9–43.18 |
Critical | 902 (68.3) | 418 (31.7) | 479.75 | 344.37–668.34 | 655.24 | 468.13–917.15 |
Length of stay | ||||||
1-2 | 2338 (49.7) | 23540 (41.7) | Reference | Reference | Reference | Reference |
3–5 | 898 (19.1) | 15916 (28.2) | 0.568 | 0.525–0.615 | 0.320 | 0.293–0.349 |
6 or more | 1473 (31.3) | 17023 (30.1) | 0.871 | 0.814–0.933 | 0.379 | 0.351–0.410 |
Admission yr. | ||||||
2001 | 435 (6.9) | 5861 (93.1) | Reference | Reference | Reference | Reference |
2002 | 479 (7.1) | 6261 (92.9) | 1.031 | 0.901–1.179 | 0.969 | 0.832–1.129 |
2003 | 515 (7.2) | 6620 (92.8) | 1.048 | 0.918–1.197 | 1.014 | 0.873–1.177 |
2004 | 554 (7.6) | 6752 (92.4) | 1.106 | 0.970–1.259 | 1.028 | 0.887–1.191 |
2005 | 594 (7.8) | 7023 (92.2) | 1.140 | 1.002–1.296 | 0.940 | 0.813–1.087 |
2006 | 575 (7.6) | 7014 (92.4) | 1.105 | 0.971–1.257 | 0.970 | 0.839–1.121 |
2007 | 638 (8.0) | 7337 (92.0) | 1.172 | 1.032–1.330 | 0.949 | 0.823–1.094 |
2008 | 475 (9.3) | 4613 (90.7) | 1.387 | 1.211–1.589 | 1.209 | 1.038–1.408 |
2009 | 444 (8.2) | 4998 (91.8) | 1.197 | 1.043–1.373 | 1.010 | 0.866–1.178 |
In this study, we identified trends as well as sociodemographic factors and causes of injuries related to TBI hospitalization and mortality. Our findings show that, from 2001 to 2009, the percentage of TBI-H in California decreased while mortality from such injuries increased. The lower percentage of TBI-H suggests that those with critical injuries may succumb before reaching a hospital, due to the lack of transportation or accessibility to adequate care, for example, living at a great distance away. In Trunkey and Blaisdel’s “trimodel distribution of trauma deaths,” they refer to this as prehospital deaths [
We found an increasing trend in TBI-M in our study. This may reflect the loss of the proverbial “golden hour” of trauma care in California that could increase early hospital deaths. It may also suggest “late deaths” due to trauma-related complications such as sepsis [
Our findings suggest a high burden of TBI in California, which can lead to substantial long-term cognitive, emotional, and functional disability [
Our findings also show that, in California, the highest percentages of TBI-H were in those of
The higher TBI hospitalizations and mortality among male relative to female had been reported in previous studies [
Our data showed that Blacks had higher adjusted odds of mortality relative to Whites, but it was not statistically significant. Different from our findings, others have reported racial differences in the incidence of TBI-related hospitalizations and mortality. For example, TBI data from the United States for 1995–2001 identifies that both Blacks and American Indians/Alaska natives as the groups with the highest TBI-related hospitalizations [
According to this California discharge data, falls were the leading cause of TBI-H in those of ages of 0–4 years old and
Although this study provides a population based analysis of TBI for California, it presents some limitations. More specifically, missing data limited our ability to generalize the findings to the general population. For example, OSPHD does not include data from the Veterans Affairs Medical Center. Also, to protect the identity of individual patients, OSHPD masks some data elements for some encounters. Masking affects age, sex, race, ethnicity, and zip code to varying degrees. Additionally, our numbers do not include patients who were seen in the emergency department or who did not receive injury related care, therefore leading to possible underestimation of the overall percentage of TBI. Also this study focused on aggregated falls and did not count for possible differences in the presentation of individual types of falls. Finally, as helpful as ICD-9 code data are for identifying burden of injury and its causal factors, its use as a research tool is limited due to its potential for missing data. This could significantly impact research outcomes [
Our findings demonstrate the recent trends of risk factors in TBI in California, showing a decrease in TBI-H over the years. They also depict an increase in the percentage of TBI-M during the same period, suggesting that TBI mortality remains a public health challenge in California. In terms of preventing acute, early, and late TBI-related deaths, our findings suggest the need for early identification of potentially fatal TBI injuries. From a primary prevention perspective, our findings also highlight the need for programs geared specifically toward falls, assaults, and motor vehicle accident-related injuries.
In addition, our results suggest differences in demographic factors associated with TBI hospitalizations and mortality in California. These include younger children, older adults, and females, who were at higher risk for fall-related TBIs; younger adults, elderly, and Hispanics, who were at higher risks for motor vehicle accidents-related TBIs; and males and Blacks who had higher risks for assault-related TBIs. Targeted injury preventative strategies for different subgroups are needed to focus on their specific risk for TBI and their common risky behavioral practices [
Traumatic brain injury
Traumatic brain injury related hospitalization
Traumatic brain injury related causes
Traumatic brain injury related mortality
Adjusted odds ratio
Office of Statewide Health Planning and Development
International Classification of Diseases, 9th Revision, Clinical Modification
International Classification of Diseases, 10th Revision, Clinical Modification.
The authors have no conflict of interests to declare.
This study was supported in part by the Endowment Grant S21MD000103 and by the Accelerating Excellence in Translational Science AXIS Grant (U54MD007598) and NIH/NCRRN/NCATS UCLA CTSI Grant UL1TR000124.