Abstract
Objective:
This study compares characteristics of American Indian/Alaska Natives (AI/AN) and non-Hispanic Whites (NHW) hospitalized for traumatic injury and examines the effect of race on hospital disposition.
Methods:
Using 2007–2014 National Trauma Data Bank data, we described differences in demographic and injury characteristics between AI/AN (n=39,656) and NHWs (n=3,309,484) hospitalized with traumatic injuries. Multivariable regressions, adjusted for demographic and injury characteristics, compared in-hospital mortality and the risk of discharge to different dispositions (inpatient rehabilitation/long term care facility, skilled nursing facility, home with home health services) rather than home between AI/AN and NHW patients.
Results:
Compared to NHWs, a higher proportion of AI/ANs were age 19–44 (49% versus 27%) years and hospitalized with assault-related injuries (25% versus 5%). AI/ANs had lower odds of dying than NHWs during hospitalization (adjusted odds ratio (aOR) 0.72, 95% CI 0.63–0.84). However, AI/ANs also had lower odds than NHWs to discharge to locations with additional health services even after controlling for injury severity (inpatient rehabilitation/long term care facilities aOR 0.79, 95% CI 0.67–0.93; skilled nursing facility aOR 0.70, 95% CI 0.49–0.98; home with home health services aOR 0.62, 95% CI 0.49–0.79).
Conclusions:
Injury patterns and acute hospitalization outcomes were significantly different for AI/ANs compared to NHWs. Injury prevention strategies targeting AI/ANs should reflect these differential injury patterns. Outcomes such as disability and access to rehabilitation services should be included when considering the burden of injury among AI/AN communities.
Keywords: American Indian, Alaska Native, Trauma, Rehabilitation, Health Care Disparity, Hospitalization
American Indian and Alaska Native (AI/AN) people are disproportionately affected by traumatic injury. Unintentional injury mortality is 2 to 3 times higher for AI/ANs than for non-Hispanic White (NHW) people,1,2 with mortality and the magnitude of disparity between AI/ANs and NHWs varying between pediatric and adult age groups.1 Among adolescents3 and 20- to 64-year-olds,4 AI/ANs are hospitalized for injury at higher rates than the general population. Differences in injury etiology between AI/ANs and the general population exist; a higher proportion of AI/ANs experience motor vehicle-related injury than NHWs (33% versus 25%) in the Washington Trauma Registry5 and the motor vehicle traffic death rate for AI/ANs was three times higher than for NHWs (41.8 versus 13.4 deaths per 100,000 people).1 Single state studies in Washington and Arizona documented a higher rate of intentional injury among AI/ANs compared to Whites, with ethnicity not included in these studies.5,6 Beyond mortality and prevalence data, there is limited information on characteristics and outcomes of AI/ANs hospitalized for traumatic injury. Using a national database to investigate injury characteristics and outcomes after trauma hospitalization among AI/ANs will further define the needs of a population that experiences a high burden of traumatic injury.
Racial/ethnic disparities in trauma outcomes exist for other racial groups.7–9 Compared with NHW adults hospitalized for traumatic injuries, Black and Hispanic adults were more likely to be uninsured or have public insurance, have intentional injuries, and lower Injury Severity Score (ISS) reflecting less severe injuries.10 In a meta-analysis, Black race was associated with a higher odds of death during trauma hospitalization compared to NHW race.7 Functional status is an important outcome for injury survivors. Rehabilitation services are an accepted means of improving functioning and quality of life10,11 but studies demonstrate racial/ethnic disparities in access to rehabilitation. After adjusting for demographic and injury characteristics, racial/ethnic disparities in discharge to inpatient rehabilitation facilities exist for Blacks and Hispanics hospitalized for traumatic injuries.10 However, Black children hospitalized with traumatic brain injury were more likely to discharge to inpatient rehabilitation facilities than NHW or Hispanic children.12 While there was no disparity in discharge to inpatient rehabilitation facilities among AI/ANs and NHWs with spinal cord injury,13 this study included only one injury type and people age 15 to 64 years. It is unknown whether there are disparities in discharge disposition among AI/ANs hospitalized for traumatic injuries across all types of traumatic injury and age groups.
In order to identify and address the disparities in trauma impact amongst AI/AN communities, this study aimed to 1) explore differences in demographic and injury characteristics between AI/ANs and NHW in the National Trauma Data Bank (NTDB) and 2) examine the association between AI/AN race and mortality and discharge location after hospitalization for traumatic injury. Because of differences in injury mortality and discharge to inpatient rehabilitation for children seen in other studies,1,12 the analyses were repeated for the pediatric cohort age 0–18 years old. We hypothesize that 1) there are differences in injury intent and mechanism between AI/ANs and NHWs 2) a higher proportion of AI/ANs hospitalized for injury will die during hospitalization compared to NHWs; and 3) AI/ANs will be less likely to discharge to inpatient rehabilitation facilities than NHWs.
Methods
Study setting and cohort
This study is a retrospective analysis of AI/AN and NHW trauma patients in the NTDB between 20072014. The American College of Surgeons maintains the NTDB, the largest repository of clinical data specifically for traumatic injuries in the United States. The NTDB contains information on over 7 million trauma cases voluntarily submitted by over 750 participating hospitals.14 Patients were included in the analysis if their race/ethnicity was reported to NTDB as AI/AN (including those with multiracial identities) or NHW and they had an inpatient admission for a traumatic injury. NTDB has two race fields; if patients were identified as AI/AN in either field they were included in the analysis as AI/AN. Patients were excluded from the NHW cohort if a non-White race was included in either race field. Patients were also excluded if they were not admitted as an inpatient, or they were discharged to another acute care facility to avoid double counting individual incidents.
Outcomes and confounders
The primary outcomes of interest were in-hospital mortality and hospital discharge location: home, home with home health services (intermittent skilled nursing and/or rehabilitation therapies delivered at home), skilled nursing facility, inpatient rehabilitation facility or long term care (grouped due to NTDB combining these categories in some years), or other (including psychiatric hospitals and law enforcement facilities).
Demographic variables include age (categorized as <5, 5–12, 13–18, 19–44, 45–65 and >65 years old), gender, and insurance/payer (private insurance, Medicare, Medicaid, uninsured (as reflected by self-pay/not billed status), no fault automobile/worker’s compensation, other government insurance, and other). Injury characteristics include injury mechanism (fall, motor vehicle collision (MVC), pedestrian, cyclist, motorcycle, other transport, firearm, cut/pierced, struck by/against, and other), blunt or penetrating trauma, intent of injury (unintentional, selfinflicted, and assault), Glasgow Coma Score (GCS) total score (categorized as mild (GCS 13–15), moderate (GCS 912), and severe (3–8)); pulse; and ISS (categorized as mild (ISS<9), moderate (ISS 9–14), severe (ISS 15–24). and extremely severe (ISS≥25)). Other variables involved the clinical decisions include primary method of transport to facility (ambulance, helicopter/plane, private vehicle/walk-in, other); hypotension in the emergency department (defined as systolic blood pressure <90mmHg for adults and children 10 years or older; <(70+(2*age))mmHg for children age 1–10 years; <70mmHg for infants age 1–12 months; and <60mmHg for neonates up to 1 month old ); and need for a ventilator (dichotomized as “yes” if the number of ventilator days was greater than 0).
Statistical Analysis
In all analyses, we examined the entire cohort and then conducted a stratified analysis for children (<19 years old) due to expected differences for children. Descriptive statistics were conducted for all the variables, with significance testing through Wald tests from univariate logistic regression with robust standard errors accounting for clustering by facility to compare differences between the AI/AN and NHW cohorts for demographic and injury characteristics and the two outcomes: in-hospital mortality and hospital discharge location. Supplemental tables 1 and 2 display results from univariate logistic regression to identify areas of discordance between AI/ANs and NHWs for demographic and injury characteristic categories. Multivariable logistic regression with robust standard errors accounting for clustering by facility was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CI) for the risk of in-hospital mortality between AI/AN and NHW patients. Multivariable multinomial logistic regression with robust standard errors accounting for clustering by facility was used to estimate ORs and 95% CIs for the risk of discharge to skilled nursing facility, inpatient rehabilitation/long term care facility, home with home health services, or other discharge location compared to discharge home as the baseline comparison group between AI/AN and NHW patients who survived to acute hospital discharge. Previous literature found age, hypotension, pulse, total GCS, ISS, and need for a ventilator provided the best risk adjustment model when using NTDB.15 For both multivariable models, these variables were included in addition to race (AI/AN or NHW) and insurance and the analyses adjusted for clustering by facility to account for correlation in unmeasured covariates between patients treated at the same hospital. While the Hausman test for the Independence of Irrelevant Alternatives assumption for multinomial logistic regression could not be used due to the clustered data, we did compare in logistic regression models the each outcome versus discharge to home and found very few differences in the coefficients obtained from multinomial regression.
Multiple imputation of missing variables was considered, but not pursued. Many of the variables in the regression model had missing data of less than 5%, but total GCS had a higher proportion of missing data at (~8%). Nearly 80% of those missing a total GCS score did not have a TBI diagnostic code recorded. A sensitivity analysis was run where all those missing a total GCS score were categorized as having a total GCS in the mild range of 1315. This did not change the magnitude or direction of the findings of the complete case regression analyses, so we did not attempt to replace missing data.
All analyses were conducted with STATA (version 13.1 Statcorp: College Station, TX). The Institutional Review Board determined the previously collected, de-identified data in this study does not meet regulatory definition of human subjects research and thus did not require Institutional Review Board approval.
Results
Of the total 3,349,140 patients included, 39,656 (1.2%) identified as AI/AN. Of the AI/AN individuals, 741 (1.9%) were identified as AI/AN in combination with another race. Table 1 displays demographic characteristics. The total cohort of AI/ANs had a higher proportion of males (66.6 versus 58.2%) and adults age 19–44 (49.4 versus 27.4%) but a lower proportion of elders 65-years or older (9.1% versus 29.7%) compared to NHWs. Among children, there was a similar proportion of males in the AI/AN and NHW cohorts. There were significant differences in payer, with AI/ANs more likely than NHWs to be covered by Medicaid (28.8% versus 8.6%) or other government insurance (15.3% versus 1.7%). Over half of AI/AN children were covered by Medicaid, compared to less than 25% of NHW children.
Table 1.
Demographic characteristics among American Indians/Alaska Natives and non-Hispanic Whites hospitalized for injury in the National Trauma Data Bank, 2007–2015
| Variable, % | AI/AN | NHW | Variable, % | AI/AN children | NHW children |
|---|---|---|---|---|---|
| (n=39,656) | (n=3,309,484) | (n=7,334) | (n=454,367) | ||
| Age, years * | Age, years ǂ | ||||
| <5 | 5.3 | 3.2 | 28.5 | 23.4 | |
| 5–12 | 5.4 | 4.4 | 29.5 | 32.2 | |
| 13–18 | 7.8 | 6.1 | 42.1 | 44.3 | |
| 19–44 | 49.4 | 27.4 | |||
| 45–64 | 22.2 | 24.8 | |||
| ≥65 | 9.1 | 29.7 | |||
| Missing | 0.8 | 4.3 | |||
| Sex* | Sex | ||||
| Male | 66.6 | 58.2 | 64.1 | 65.2 | |
| Female | 33.4 | 41.7 | 35.9 | 34.8 | |
| Missing | <0.1 | 0.1 | |||
| Insurance status* | Insurance status* | ||||
| Private insurance | 13.6 | 29.1 | 17.4 | 49.9 | |
| Medicare | 9.9 | 28.5 | 0.3 | 0.3 | |
| Medicaid | 28.8 | 8.6 | 51 | 23.7 | |
| Uninsured | 16.1 | 10.5 | 9.5 | 5.9 | |
| No Fault Auto, Worker’s Comp | 4.9 | 8.7 | 3.6 | 5.1 | |
| Other government insurance | 15.3 | 1.7 | 8.6 | 2.1 | |
| Other | 4.9 | 4.7 | 3.9 | 4.6 | |
| Missing | 6.5 | 8.2 | 5.6 | 8.3 | |
Abbreviations: AI/AN (American Indian/Alaska Native); NHW (non-Hispanic White)
Note: indicates p-value <.001 for differences between AI/AN and NHW cohorts.
indicates p-value <.01 for differences between AI/AN and NHW cohorts. P-values obtained from Wald tests from univariate logistic regression with robust standard errors accounting for clustering by facility to compare differences between the AI/AN and NHW cohorts
There were several differences in injury characteristics between the AI/AN and NHW cohorts, shown in Table 2. AI/ANs were more likely to have intentional injuries than NHW, with higher proportion of assault (24.5% for AI/ANs versus 5.2% for NHW) and self-inflicted injuries (2.4% versus 1.4% for AI/ANs and NHWs respectively). As compared with patients with unintentional injuries, those with injuries from assault were six times more likely to be AI/AN rather than NHW (OR 6.1, 95% CI 4.8–7.7, Supplemental Table 2). AI/AN children also had a higher proportion of intentional injuries (assault and self-inflicted) than NHW children (13.3% versus 4.9%). The proportion of people injured in falls was much lower in AI/ANs than NHWs (27.7% versus 47.9%) but “cut/pierce” and “struck by/against” were much higher among AI/ANs (9.0% versus 2.6% and 14.9% versus 5.7%, respectively). AI/ANs were more likely than NHWs to have an ISS under 9 (49.0% versus 42.2%), representing less severe injury status, but had a similar proportion with ISS of 25 or greater (7.4% versus 7.2%).
Table 2.
Injury and clinical characteristics among American Indians/Alaska Natives and non-Hispanic Whites hospitalized for injury in the National Trauma Data Bank, 2007–2015
| Variable, % | AI/AN | NHW | Variable, % | AI/AN children | NHW children |
|---|---|---|---|---|---|
| (n=39,656) | (n=3,309,484) | (n=7,334) | (n=454,367) | ||
| Intent of injury* | Intent of injury* | ||||
| Unintentional | 71.6 | 92.5 | 85.2 | 93.8 | |
| Assault | 24.5 | 5.2 | 11.8 | 4.2 | |
| Self-inflicted | 2.4 | 1.4 | 1.5 | 0.7 | |
| Other/Unknown | 1.2 | 0.4 | 1.3 | 0.5 | |
| Missing | 0.2 | 0.5 | 0.2 | 0.7 | |
| Injury Type* | Injury Type* | ||||
| Blunt | 78.7 | 89.4 | 78 | 84.9 | |
| Penetrating | 12.0 | 4.4 | 8 | 3.5 | |
| Other | 9.3 | 6.2 | 14 | 11.7 | |
| Injury Mechanism* | Injury Mechanism* | ||||
| Fall | 27.7 | 47.9 | 29.6 | 36.1 | |
| MVC | 21.2 | 18.5 | 20 | 17.3 | |
| Pedestrian | 4.6 | 2.6 | 4.8 | 3.3 | |
| Cyclist | 2.0 | 2.6 | 4.3 | 5.5 | |
| Motorcycle | 1.7 | 5.2 | 0.7 | 1.5 | |
| Other transport | 0.1 | 0.1 | 0.1 | <0.1 | |
| Firearm | 2.8 | 1.6 | 2.5 | 1.1 | |
| Cut/Pierce | 9.0 | 2.6 | 5.3 | 2.2 | |
| Struck by/Against | 14.9 | 5.7 | 9.2 | 10.7 | |
| Other | 6.2 | 3.1 | 7.3 | 5.5 | |
| Missing | 9.8 | 10.1 | 16.2 | 16.8 | |
| Transferred from another facility* | Transferred from another facility* | ||||
| Yes | 49.0 | 29.5 | 58 | 43.3 | |
| No | 50.6 | 70.3 | 41.7 | 56.5 | |
| Missing | 0.4 | 0.2 | 0.3 | 0.2 | |
| Mode of Transport* | Mode of Transport* | ||||
| Ambulance | 52.2 | 67.2 | 42.9 | 54.6 | |
| Helicopter/Plane | 30.5 | 12.6 | 33.2 | 15.0 | |
| Private vehicle/Walk-in | 11.1 | 14.2 | 17.8 | 23.6 | |
| Other | 0.6 | 0.7 | 0.5 | 0.7 | |
| Missing | 5.6 | 5.3 | 5.5 | 6.1 | |
| Hypotensive in ED | Hypotensive in ED | ||||
| Yes | 5.7 | 5.5 | 11.0 | 9.6 | |
| No | 94.3 | 94.5 | 89.0 | 90.4 | |
| Injury Severity Score* | Injury Severity Score | ||||
| <9 | 49.0 | 42.2 | 54.8 | 53.1 | |
| 9–14 | 30.3 | 35.7 | 27.7 | 29.1 | |
| 15–24 | 11.9 | 12.3 | 10.2 | 9.3 | |
| ≥25 | 7.4 | 7.2 | 5.8 | 5.4 | |
| Missing | 1.4 | 2.6 | 1.5 | 3.2 | |
| Total GCS* | Total GCS* | ||||
| 13–15 | 77.7 | 84.5 | 80 | 85.2 | |
| 9–12 | 3.6 | 2.0 | 2.6 | 1.6 | |
| 3–8 | 11.0 | 5.8 | 9.1 | 5.3 | |
| Missing | 7.7 | 7.7 | 8.3 | 7.9 | |
| ED Disposition* | ED Disposition* | ||||
| Floor Bed | 43.2 | 51.4 | 45.9 | 52.1 | |
| ICU | 25.1 | 22.1 | 23.2 | 19.6 | |
| OR | 16.6 | 12.2 | 19.8 | 16.6 | |
| Telemetry/stepdown | 5.1 | 7.9 | 2.0 | 3.2 | |
| Observation (<24 hrs) | 2.5 | 2.4 | 1.9 | 3.7 | |
| N/A – Directly Admitted | 5.4 | 2.5 | 5.3 | 3.0 | |
| Missing | 2.0 | 1.5 | 1.7 | 1.8 | |
| Hospital Disposition* | Hospital Disposition* | ||||
| Deceased/Expired | 2.6 | 3.9 | 1.6 | 1.3 | |
| Home, no services | 79.7 | 61.7 | 91.2 | 91.6 | |
| Home with home health services | 2.0 | 5.4 | 1.2 | 2.1 | |
| Skilled nursing facility | 5.4 | 14.6 | 0.4 | 0.3 | |
| Inpatient Rehabilitation/Long Term Care facility | 7.2 | 10.1 | 4.2 | 2.9 | |
| Other | 2.6 | 4.1 | 0.9 | 1.1 | |
| Missing (including not applicable) | 0.5 | 0.8 | 0.6 | 0.8 | |
Abbreviations: AI/AN (American Indian/Alaska Native); NHW (non-Hispanic White); ED (Emergency Department); GGS (Glasgow Coma Scale); ICU (Intensive Care Unit); OR (Operating Room).
Note: indicates p-value <.001 for differences between AI/AN and NHW cohorts. ǂindicates p-value <.01 for differences between AI/AN and NHW cohorts. § indicated p-value<.05 for differences between AI/AN and NHW cohorts. P-values were obtained from Wald tests from univariate logistic regression with robust standard errors accounting for clustering by facility to compare differences between the AI/AN and NHW cohort.
Glasgow Coma Scale scores are used clinically to describe the severity of TBI, where 13–15 indicates mild, 9–12 moderate, and 3–8 severe injury. Other hospital disposition included intermediate care facilities, hospice, leaving against medical advice, court systems, psychiatric hospital, and other institutions.
In both the full cohort and pediatric sub-group, AI/ANs were more likely to have been transferred from another healthcare facility (49.0% versus 29.5% for the entire cohort and 58.0% versus 43.4% for children) and to have been transported by air (30.5% versus 12.6% and 33.2% versus 15.0% for children). A higher proportion of AI/ANs were admitted to the operating room or intensive care unit from the emergency department compared to NHWs (16.6% versus 12.2% and 25.1 versus 22.1%, respectively). (Table 2)
Outcomes
Without adjusting for injury variables, fewer AI/ANs died in-hospital due to traumatic injuries compared to NHWs (2.6% AI/ANs versus 3.9% NHW). The differences in the distribution of disposition from acute care hospitalization between AI/ANs and NHWs were also statistically different. Almost 80% of AI/AN people were discharged home without services, compared to only 62% of NHWs. NHWs were more likely than AI/ANs to discharge to inpatient rehabilitation/long term care facilities (10.1% versus 7.2%) or skilled nursing facilities than AI/ANs (14.6% versus 5.4%). (Table 2)
After adjusting for demographic and injury characteristics (Table 3), AI/ANs have lower odds of dying during trauma hospitalization than NHWs (OR 0.72, 95% CI 0.63–0.84). In general, increasing age was associated with higher odds of death, but children under 5 years had higher odds of death than adults age 19–44 years to die (OR 1.33, 95% 1.22–1.45). Being uninsured was related to higher odds of death (OR 1.54, 95% CI 1.45–1.64), as was having Medicare insurance (OR 1.48, 95% CI 1.41–1.55). Among children, race was not independently associated with odds of death. Children under age 5 years had higher odds of death than teenagers (OR 2.01, 95% CI 1.79–2.26). Insurance status was also associated with odds of mortality, with children covered by Medicare (OR 5.29, 95% CI 2.62–10.65) or uninsured (OR 2.20, 95% CI 1.85–2.62) having higher odds of death.
Table 3.
Factors associated with in-hospital mortality among American Indians/Alaska Natives and non-Hispanic Whites in the National Trauma Data Bank, 2007–2015
| All ages | Children (0–18) | |||
|---|---|---|---|---|
| Factors | aOR | 95% CI | aOR | 95% CI |
| Race/ethnicity | ||||
| NHW | Reference | Reference | ||
| AI/AN | 0.72 | (0.63–0.84) | 0.81 | (0.62–1.06) |
| Age group | ||||
| <5 yrs | 1.33 | (1.22–1.45) | 2.01 | (1.79–2.26) |
| 5–12 | 0.70 | (0.62–0.80) | 0.92 | (0.82–1.04) |
| 13–18 | 0.89 | (0.84–0.94) | Reference | |
| 19–44 | Reference | |||
| 45–64 | 2.20 | (2.12–2.28) | ||
| 65+ | 9.80 | (8.87–10.83) | ||
| Hypotensive in ED | 2.93 | (2.79–3.07) | 4.66 | (3.94–5.51) |
| Heart rate in ED | 1.00 | (1.00–1.00) | 1.00 | (0.99–1.00) |
| Injury Severity Score | ||||
| <9 | Reference | Reference | ||
| 9–14 | 1.97 | (1.81–2.13) | 1.76 | (0.88–3.53) |
| 15–24 | 2.96 | (2.68–3.27) | 3.86 | (1.70–8.78) |
| 25+ | 11.57 | (10.28–13.04) | 23.56 | (10.38–53.49) |
| Total GCS | ||||
| 3–8 | Reference | Reference | ||
| 9–12 | 0.41 | (0.38–0.43) | 0.09 | (0.07–0.12) |
| 13–15 | 0.14 | (0.13–0.16) | 0.02 | (0.01–0.03) |
| Need for ventilator | 4.80 | (4.34–5.31) | 1.25 | (1.02–1.54) |
| Insurance | ||||
| Private | Reference | Reference | ||
| Medicare | 1.48 | (1.41–1.55) | 5.29 | (2.62–10.65) |
| Medicaid | 0.99 | (0.94–1.05) | 1.05 | (0.91–1.22) |
| Uninsured | 1.54 | (1.45–1.64) | 2.20 | (1.85–2.62) |
| No Fault Auto/Worker’s Compensation | 0.81 | (0.75–0.88) | 0.96 | (0.83–1.11) |
| Other Government | 1.09 | (0.98–1.22) | 0.78 | (0.59–1.05) |
| Other | 1.13 | (0.98–1.30) | 1.18 | (0.95–1.47) |
Abbreviations: aOR (adjusted odds ratio); AI/AN (American Indian/Alaska Native); NHW (non-Hispanic White); ED (Emergency Department); GGS (Glasgow Coma Scale)
Note: Multivariable logistic regression was used to compare the risk of in-hospital mortality between AI/AN and NHW patients hospitalized for injury at facilities submitting data to the NTDB.
Among those who survived to hospital discharge, the relative odds of receiving a discharge outcome other than home without home health services after trauma hospitalization was lower for AI/ANs than NHWs across all discharge outcomes after holding demographic and injury characteristics constant. As shown in Table 4, AI/ANs had lower odds than NHWs to be discharged to an inpatient rehabilitation/long term care facility (OR 0.79, 95% CI 0.670.93), a skilled nursing facility (OR 0.70, 95% CI 0.49–0.98), home with home health services (OR 0.41, 95% CI 0.30–0.55), or to other locations (OR 0.62, 95% CI 0.49–0.79). Children had lower odds than adults to be discharged to locations other home. For instance, compared to adults age 19–44, children in all age groups had lower odds of discharge to an inpatient rehabilitation/long term care facility (children <5 years OR 0.18, 95% CI 0.13–0.25; age 512 years OR 0.19, 95% CI 0.15–0.24; age 13–18 OR 0.61, 95% CI 0.57–0.66). Holding all variables constant, the odds of being discharged to location other than home without health services was also lower for all discharge location for people without insurance was lower by a factor of 0.45 compared to those with private insurance.
Table 4.
Factors associated with location of discharge after injury hospitalization among American Indians/Alaska Natives and non-Hispanic Whites in the National Trauma Data Bank, 2007–2015
| Inpatient Rehabilitation/ Long Term Care | Skilled Nursing Facility | Home with Home Health Services | Other dispositions | |||||
|---|---|---|---|---|---|---|---|---|
| Factors | aOR | 95% CI | aOR | 95% CI | aO R | 95% CI | aO R | 95% CI |
| Race/ethnicity | ||||||||
| NHW | Reference | Reference | Reference | Reference | ||||
| AI/AN | 0.79 | (0.67–0.93) | 0.70 | (0.49–0.98) | 0.41 | (0.30, 0.55) | 0.62 | (0.49-0.79) |
| Race/ethnicityAge group | ||||||||
| <5 yrs | 0.18 | (0.13–0.25) | 0.09 | (0.06–0.13) | 0.25 | (0.19, 0.32) | 0.10 | (0.08-0.13) |
| 5–12 | 0.19 | (0.15–0.24) | 0.03 | (0.02–0.04) | 0.25 | (0.20, 0.32) | 0.10 | (0.08-0.15) |
| 13–18 | 0.61 | (0.57–0.66) | 0.16 | (0.15–0.18) | 0.55 | (0.51, 0.60) | 0.49 | (0.45-0.54) |
| 19–44 | Reference | Reference | Reference | Reference | ||||
| 45–64 | 1.92 | (1.86–1.98) | 5.04 | (4.78–5.31) | 1.69 | (1.60, 1.77) | 1.55 | (1.50-1.61) |
| 65+ | 5.80 | (5.38–6.25) | 31.09 | (28.28-34.17) | 2.99 | (2.76, 3.24) | 3.23 | (2.97-3.51) |
| Race/ethnicityHypotensive in ED | 1.42 | (1.37–1.48) | 1.48 | (1.42–1.55) | 1.25 | (1.18,1.33) | 1.29 | (1.22-1.36) |
| Race/ethnicityHeart rate in ED | 1.00 | (1.00–1.01) | 1.00 | (1.00–1.01) | 1.00 | (1.00, 1.00) | 1.01 | (1.01-1.01) |
| ISS | ||||||||
| <9 | Reference | Reference | Reference | Reference | ||||
| 9–14 | 2.83 | (2.69–2.97) | 2.28 | (2.20–2.37) | 1.46 | (1.38, 1.54) | 1.79 | (1.66-1.93) |
| 15–24 | 3.51 | (3.26–3.78) | 1.64 | (1.48–1.73) | 1.46 | (1.36, 1.56) | 2.20 | (2.00-2.42) |
| 25+ | 9.02 | (8.28–9.83) | 4.13 | (3.78–4.51) | 2.24 | (2.04, 2.47) | 5.28 | (4.63-6.01) |
| Total GCS | ||||||||
| 3–8 | Reference | Reference | Reference | Reference | ||||
| 9–12 | 0.84 | (0.79–0.90) | 1.09 | (0.99–1.20) | 0.99 | (0.91, 1.08) | 1.04 | (0.96-1.13) |
| 13–15 | 0.52 | (0.47–0.57) | 0.60 | (0.53–0.67) | 1.03 | (0.93, 1.14) | 0.61 | (0.54-0.69) |
| Need for ventilator | 3.54 | (3.18–3.93) | 2.38 | (2.12–2.66) | 1.58 | (1.38, 1.81) | 3.07 | (2.69-3.51) |
| Insurance | ||||||||
| Private | Reference | Reference | Reference | Reference | ||||
| Medicare | 1.82 | (1.72–1.93) | 2.33 | (2.17–2.51) | 1.64 | (1.53, 1.76) | 2.11 | (1.94-2.28) |
| Medicaid | 1.03 | (0.97–1.09) | 1.76 | (1.64–1.88) | 1.06 | (0.96, 1.16) | 1.64 | (1.50-1.79) |
| Uninsured | 0.45 | (0.41–0.49) | 0.36 | (0.33–0.40) | 0.54 | (0.47, 0.62) | 1.05 | (0.94-1.18) |
| No Fault Auto/ Worker’s Compensation | 1.12 | (1.03–1.23) | 0.75 | (0.68–0.83) | 1.21 | (1.08, 1.37) | 1.15 | (0.99-1.33) |
| Other Government | 0.81 | (0.72–0.92) | 0.80 | (0.71–0.91) | 0.79 | (0.57, 1.11) | 1.14 | (0.99-1.32) |
| Other | 0.84 | (0.72–0.98) | 1.34 | (0.90–1.99) | 0.86 | (0.65, 1.13) | 1.64 | (1.34-2.02) |
Abbreviations: aOR (adjusted odds ratio); AI/AN (American Indian/Alaska Native); NHW (nonHispanic White); ED (Emergency Department); ISS (Injury Severity Score); GGS (Glasgow Coma Scale)
Note: Multivariable multinomial regressions were used for this analysis of people who survived to hospital discharge, with discharge to home without home health services as the baseline comparator. Other dispositions included psychiatric hospitals and law enforcement facilities. A stratified analysis for children 18 years old and younger can be found in Supplemental Table 3.
When comparing amongst children, the odds of being discharged to an inpatient rehabilitation/long term care facility are greater by a factor of 1.41 for AI/AN children than NHW children holding all other variables constant (OR 1.41, 95% CI 1.15–1.73) (Supplemental Table 3). Younger children had lower odds than teenagers to be discharged to inpatient rehabilitation/long term care facilities rather than home (children <5 years OR 0.31, 95% CI 0.22–0.45; children 5–12 years OR 0.32, 95% CI 0.26–0.41). Relative to discharge home, uninsured children had decreased odds of discharge to an inpatient rehabilitation/long term care facility (OR 0.64, 95% CI 0.53–0.76) compared to children with private insurance.
Discussion
This analysis of the NTDB found several notable differences in the demographics, injury characteristics, and discharge disposition between AI/ANs and NHWs hospitalized for traumatic injuries. A majority of the AI/AN cohort was working age, with a relatively small percentage (9.1%) over age 65 years. In contrast, one third of the NHW cohort was comprised of those over 65 years. Over one quarter of the AI/AN sample, but less than 10% of the NHW sample, were hospitalized for an intentional injury. When adjusting for key demographic and injury severity characteristics, AI/ANs had lower odds of during hospitalization than NHWs, but higher odds than NHWs to be discharged home without home health services rather than to an inpatient rehabilitation or long-term care facility, skilled nursing facility, or home with home health services. AI/AN children, however, had higher odds than NHW children to be discharged to inpatient rehabilitation/long term care facilities rather than home.
The decreased odds of in-hospital trauma mortality for AI/ANs compared to NHWs found in this study contrasts with the higher rate of injury mortality for AI/ANs compared to NHWs found in studies that linked Indian Health Service (IHS) registration records with the US National Death Index.1,16 However, differences in pre-hospital factors – such as rural location or access to emergency medical services – likely contribute to increased AI/AN injury mortality at the scene of the injury, meaning those that survive to hospitalization reflect a population at lower risk of death.17,18 This further highlights the importance of primary injury prevention among AI/AN communities in decreasing injury mortality. IHS’s Injury Prevention Program and several tribal communities have developed culturally and community-specific initiatives to prevent injuries.18–22 Based on the injury patterns found in this study, efforts to reduce injuries amongst younger populations, and those related to falls, motor vehicle collisions, suicides and assaults would be beneficial for AI/AN communities.
Most patients were discharged home without home health services, with a higher proportion of AI/ANs than NHW receiving this disposition. Given the severity of clinical and injury characteristics of this hospitalized sample, the known benefits of rehabilitative services and the known barriers and limited access to community resources for Medicaid patients and patients from minority racial/ethnic groups,8,23 this is concerning and could contribute to disparities in functional, vocational and other outcomes. Further study is needed to determine whether AI/ANs who discharge directly home without health services after trauma hospitalization have their long-term functional needs adequately addressed.
In addition, this study found that AI/ANs who survived to hospital discharge had a lower odds of being discharged to an inpatient rehabilitation/long term care facility rather than home compared to NHWs, even when controlling for insurance status. This corresponds with other analyses of the NTDB that found minority race was associated with decreased likelihood of discharge to inpatient rehabilitation compared to NHWs, though these analyses did not include specific analyses of AI/AN people.10,24,25 The only other NTDB analysis focusing specifically on AI/ANs found that there was no racial disparity in discharge to rehabilitation facilities after hospitalization for spinal cord injury.13 Spinal cord injury is a diagnosis with a clear indication for intensive rehabilitation, with NTDB analyses finding 47% of adults with spinal cord injury discharged to an inpatient rehabilitation facility13 compared to only 5% of adults with all injury types.10 To be admitted to an inpatient rehabilitation facility, one must have physiatry and therapy consultations; be deemed a candidate for and accepted by an inpatient rehabilitation facility; and agree to discharge to an inpatient rehabilitation facility. It is unclear at what point in this process the disparity in discharge to inpatient rehabilitation facility for AI/ANs arises, but many of these steps involve individual decision making where implicit bias, social determinants of health, or lack of geographically accessible rehabilitation services could impact access to inpatient rehabilitation facility for AI/ANs.
While overall AI/ANs had lower odds of discharge to inpatient rehabilitation/long term care facilities, we found AI/AN children had higher odds than NHW children to discharge to inpatient rehabilitation/long term care facilities. In a separate study of data from inpatient rehabilitation facilities across the United States, AI/AN children admitted to inpatient rehabilitation facilities with traumatic brain injuries had higher motor function scores at admission compared to NHW children.26 It could be that AI/AN children are admitted to inpatient rehabilitation facilities at higher rates and with higher functional levels than NHW children because they lack access to pediatric rehabilitation therapists in their home communities; differential access to outpatient rehabilitation services has been shown in Hispanic populations.8 Without access to outpatient or home health rehabilitation services, an inpatient rehabilitation facility admission is the only option for rehabilitation services to address functional impairments. Further research examining these associations is recommended.
This study is limited by several factors. Racial misclassification of AI/ANs is common in healthcare records,27–29 and it is possible that more accurate identification of AI/ANs in NTDB would affect the analyses. Also, the NTDB is not a population-based sample14 and the facilities contributing data to NTDB may not represent all of the facilities at which AI/AN people receive their trauma care. We excluded patients from the multivariable analyses if they were missing data, increasing the potential for bias if the data are missing because of a factor related to the outcomes measured.30 Aligned with standard methods in NTDB analyses, we did not include all the individual and injury factors that may impact in-hospital mortality, instead choosing to use the variables found by Haider et al. to be the best predictors of mortality.15 Similarly, not all the individual or injury factors that influence discharge to inpatient rehabilitation could be included in the analysis. Functional status, a key factor in admission to inpatient rehabilitation facilities, is not collected by NTDB, though it is expected that more severe injuries – captured in this study using ISS – result in more functional limitations. There are other factors affecting inpatient rehabilitation candidacy, such as ability to participate in three hours of therapy daily, which are not collected in NTDB. Finally, referral to or utilization of outpatient clinic-based rehabilitation services is not captured in NTDB, so this analysis cannot address this means of accessing rehabilitation services after traumatic injury hospitalization.
Conclusions and Public Health Implications
Amongst those hospitalized for injuries at hospitals participating in the NTDB, AI/ANs are younger, more likely to have an intentional injury (assault or self-inflicted), and have a lower odds of dying during hospitalization than NHWs. After hospitalization for traumatic injury, AI/ANs are more likely to be discharged home without home health services and have lower odds than NHW to be discharged to rehabilitation facilities. There are several key points of intervention in the clinical care process that might improve referral rates to rehabilitation facilities, beginning with universal assessment of rehabilitation needs and improved access to rehabilitation services in the community. The impact of the rehabilitation referral pattern on long-term functional outcomes for AI/ANs after injury hospitalization is unknown and requires further study. Outcomes such as measures of functional impairment and access to and utilization of rehabilitation services should be included when considering the burden of injury for AI/AN populations.
Supplementary Material
Acknowledgments
Disclosures: Dr. Fuentes’ time on this project was supported by the Pediatric Injury Training Program (T32-HD057822) and the Rehabilitation Medicine Scientist Training Program (K12-HD001097). Dr. Moore’s time on this project was supported by the National Center for Advancing Translational Sciences of the National Institutes of Health (KL2TR000421). Mr. Frank’s time on this project was supported by the Northwest Center for Public Health Practice (NWCPHP) at the University of Washington and Behavioral Health Workforce Education and Training for Professionals (HRSA-14–077).
Abbreviations:
- Aor
Adjusted Odds Ratio
- AI/AN
American Indian/Alaska Native
- GCS
Glasgow Coma Score
- HIS
Indian Health Service
- ISS
Injury Severity Scale
- MVC
Motor Vehicle Collision
- NTDB
National Trauma Data Bank®
- NHW
Non-Hispanic White
Footnotes
Conflicts of interest: The authors have no conflicts of interest to disclose.
References
- 1.Murphy T, Pokhrel P, Worthington A, Billie H, Sewell M, Bill N. Unintentional Injury Mortality Among American Indians and Alaska Natives in the United States, 1990–2009. Am J Public Health. 2014;104(S3):S470–S480. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Wong CA, Gachupin FC, Holman RC, et al. American Indian and Alaska Native Infant and Pediatric Mortality, United States, 1999–2009. Am J Public Health. 2014;104(S3):S320–S328. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Johnson SJ, Sullivan M, Grossman DC. Hospitalizations for injury among American Indian youth in Washington. West J Med. 1999;171(1):10–14. [PMC free article] [PubMed] [Google Scholar]
- 4.Rutland-Brown W, Wallace LJ, Faul MD, Langlois JA. Traumatic brain injury hospitalizations among American Indians/Alaska Natives. J Head Trauma Rehabil. 2005;20(3):205–214. [DOI] [PubMed] [Google Scholar]
- 5.Hoopes MJ, Dankovchik J, Weiser T, et al. Uncovering a missing demographic in trauma registries: epidemiology of trauma among American Indians and Alaska Natives in Washington State. Inj Prev. 2015; 21(5):335–43. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Linton KF, Kim BJ. Traumatic brain injury as a result of violence in Native American and Black communities spanning from childhood to older adulthood. Brain Inj. 2014;28(8):1076–1081. [DOI] [PubMed] [Google Scholar]
- 7.Haider AH, Weygandt PL, Bentley JM, et al. Disparities in trauma care and outcomes in the United States: a systematic review and meta-analysis. J Trauma Acute Care Surg. 2013;74(5):1195–1205. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Moore M, Jimenez N, Rowhani-Rahbar A, et al. Availability of Outpatient Rehabilitation Services for Children After Traumatic Brain Injury: Differences by Language and Insurance Status. Am J Phys Med Rehabil. 2016;95(3):204–213. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Staudenmayer KL, Diaz-Arrastia R, de Oliveira A, Gentilello LM, Shafi S. Ethnic disparities in long-term functional outcomes after traumatic brain injury. J Trauma. 2007;63(6):1364–1369. [DOI] [PubMed] [Google Scholar]
- 10.Englum BR, Villegas C, Bolorunduro O, et al. Racial, ethnic, and insurance status disparities in use of posthospitalization care after trauma. J Am Coll Surg. 2011;213(6):699–708. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Centers for Disease Control and Prevention. Report to Congress on Traumatic Brain Injury In the United States: Epidemiology and Rehabilitation. Atlanta, GA: National Center for Injury Prevention and Control; Division of Unintentional Injury Prevention; 2015. [Google Scholar]
- 12.Haider AH, Efron DT, Haut ER, DiRusso SM, Sullivan T, Cornwell EE. Black children experience worse clinical and functional outcomes after traumatic brain injury: an analysis of the National Pediatric Trauma Registry. J Trauma. 2007;62(5):1259–1262; discussion 1262–1253. [DOI] [PubMed] [Google Scholar]
- 13.Cook AD, Ward JG, Chapple KM, Akinbiyi H, Garrett M, Moore FO 3rd. Race and rehabilitation following spinal cord injury: equality of access for American Indians/Alaska Natives compared to other racial groups. Inj Epidemiol. 2015;2(1):17. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.American College of Surgeons Committee on Trauma. National Trauma Data Bank 2014 Annual Report. Chicago, IL: American College of Surgeons; 2014. [Google Scholar]
- 15.Haider AH, Hashmi ZG, Zafar SN, et al. Developing best practices to study trauma outcomes in large databases: an evidence-based approach to determine the best mortality risk adjustment model. J Trauma Acute Care Surg. 2014;76(4):1061–1069. [DOI] [PubMed] [Google Scholar]
- 16.Espey DK, Jim MA, Cobb N, et al. Leading causes of death and all-cause mortality in American Indians and Alaska Natives. Am J Public Health. 2014;104 Suppl 3:S303–311. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Traumatic brain injury among American Indians/Alaska Natives--United States, 1992–1996. MMWR Morb Mortal Wkly Rep. 2002;51(14):303–305. [PubMed] [Google Scholar]
- 18.Bowser TR, Don W. Developing A Global Positioning System (GPS) to Improve Emergency Response on the Tohono O’odham Nation. The IHS Primary Care Provider. 2012;37(7):164–167. Available at https://www.ihs.gov/injuryprevention/includes/themes/responsive2017/display_objects/documents/general-injury-prevention/Developing-a-Global-Positioning-System-to-Improve-EmergencyResponse-on-the-Tohono-Oodham-Nation-2012.pdf [Google Scholar]
- 19.West BA, Naumann RB. Tribal motor vehicle injury prevention programs for reducing disparities in motor vehicle-related injuries. MMWR Suppl. 2014;63(1):28–33. [PubMed] [Google Scholar]
- 20.Lapidus JA, Smith NH, Lutz T, Ebel BE. Trends and correlates of child passenger restraint use in 6 Northwest tribes: the Native Children Always Ride Safe (Native CARS) project. Am J Public Health. 2013;103(2):355–361. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Berns RM, Tomayko EJ, Cronin KA, Prince RJ, Parker T, Adams AK. Development of a Culturally Informed Child Safety Curriculum for American Indian Families. J Prim Prev. 2017;38(1–2):195–205. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Cwik MF, Tingey L, Maschino A, et al. Decreases in Suicide Deaths and Attempts Linked to the White Mountain Apache Suicide Surveillance and Prevention System, 2001–2012. Am J Public Health. 2016;106(12):2183–2189. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Fuentes MM, Thompson L, Quistberg DA, et al. Auditing Access to Outpatient Rehabilitation Services for Children With Traumatic Brain Injury and Public Insurance in Washington State. Arch Phys Med Rehabil. 2017;98(9):1763–1770.e7. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Shafi S, de la Plata CM, Diaz-Arrastia R, et al. Ethnic disparities exist in trauma care. J Trauma. 2007;63(5):1138–1142. [DOI] [PubMed] [Google Scholar]
- 25.Asemota AO, George BP, Cumpsty-Fowler CJ, Haider AH, Schneider EB. Race and insurance disparities in discharge to rehabilitation for patients with traumatic brain injury. J Neurotrauma. 2013;30(24):2057–2065. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Fuentes MM, Jimenez N, Apkon SD, Rivara FP. Functional outcomes during inpatient rehabilitation for American Indian and Alaska Native children with traumatic brain injury. J Pediatr Rehabil Med. 2016;9(2):133–141. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27.Haozous EA, Strickland CJ, Palacios JF, Solomon TGA. Blood Politics, Ethnic Identity, and Racial Misclassification among American Indians and Alaska Natives. J Environ Public Health. 2014;2014:321604. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 28.Jim MA, Arias E, Seneca DS, et al. Racial Misclassification of American Indians and Alaska Natives by Indian Health Service Contract Health Service Delivery Area. Am J Public Health. 2014;104(S3):S295–S302. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Smith N, Iyer RL, Langer-Gould A, et al. Health plan administrative records versus birth certificate records: quality of race and ethnicity information in children. BMC Health Serv Res. 2010;10:316. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 30.Haider AH, Saleem T, Leow JJ, et al. Influence of the National Trauma Data Bank on the study of trauma outcomes: is it time to set research best practices to further enhance its impact? J Am Coll Surg. 2012;214(5):756–768. [DOI] [PMC free article] [PubMed] [Google Scholar]
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