Does Health Care Insurance Affect Outcomes after Traumatic Brain Injury? Analysis of the National Trauma Databank RODRIGO F. ALBAN, M.D., CHERISSE BERRY, M.D., ERIC LEY, M.D., JAMES MIROCHA, M.S., DANIEL R. MARGULIES, M.D., ARETI TILLOU, M.D., ALI SALIM, M.D.
From the Department of Surgery, Division of Trauma and Critical Care, Cedars-Sinai Medical Center, Los Angeles, California Increasing evidence indicates insurance status plays a role in the outcome of trauma patients; however its role on outcomes after traumatic brain injury (TBI) remains unclear. A retrospective review was queried within the National Trauma Data Bank. Moderate to severe TBI insured patients were compared with their uninsured counterparts with respect to demographics, Injury Severity Score, Glasgow Coma Scale score, and outcome. Multivariate logistic regression analysis was used to determine independent risk factors for mortality. Of 52,344 moderate to severe TBI patients, 41,711 (79.7%) were insured. Compared with the uninsured, insured TBI patients were older (46.1 6 22.4 vs 37.3 6 16.3 years, P \ 0.0001), more severely injured (ISS $ 16: 78.4% vs 74.4%, P \ 0.0001), had longer intensive care unit length of stay (6.0 6 9.4 vs 5.1 6 7.6, P \ 0.0001) and had higher mortality (9.3% vs 8.0%, P \ 0.0001). However, when controlling for confounding variables, the presence of insurance had a significant protective effect on mortality (adjusted odds ratio 0.89; 95% confidence interval: 0.82–0.97, P 5 0.007). This effect was most noticeable in patients with head abbreviated injury score 5 5 (adjusted odds ratio 0.7; 95% confidence interval: 0.6–0.8, P \ 0.0001), indicating insured severe TBI patients have improved outcomes compared with their uninsured counterparts. There is no clear explanation for this finding however the role of insurance in outcomes after trauma remains a topic for further investigation.
2007 report by the United States Census Bureau, over 15 per cent of the population A in the United States lack basic health coverage. This CCORDING TO A
1
lack of access to healthcare coverage is particularly pronounced in minorities such as African Americans and Hispanics.2 The relationship between lack of insurance and health care outcomes in acute and chronic disease is well documented.3–6 Recently, the impact of insurance status on trauma outcomes has been studied.7–9 Traumatic Brain Injury (TBI) continues to be a significant cause of death and disability after trauma in the United States with interventions targeting secondary brain insults having failed to demonstrate a convincing survival benefit.10–12 Based on the accepted mechanisms of primary and secondary brain injury, the insurance status of the injured patient would
Presented at the 21st Annual Scientific Meeting of the Southern California Chapter of the American College of Surgeons in Santa Barbara, CA, January 22–24, 2010. Address correspondence and reprint requests to Ali Salim, M.D., Cedars-Sinai Medical Center, Department of Surgery, 8700 Beverly Boulevard, Suite 8215N, Los Angeles, CA 90048. E-mail:
[email protected].
not be expected to have any influence on outcomes. Despite the growing body of evidence demonstrating poor outcomes in persons lacking health insurance, there have been few studies in the literature addressing the role of insurance on outcomes after isolated TBI. Using the National Trauma Data Bank (NTDB), the purpose of this study was to determine if insurance status plays a significant role in outcomes in patients with isolated TBI. We hypothesize that insurance status has no effect on outcomes in this target patient population. Methods
This is a retrospective review using the NTDB version 6.2 (2000–2005). We included data from all patients with isolated TBI, as defined by a head abbreviated injury score (AIS) $ 3 with no significant extracranial injuries (AIS < 3 for all other anatomical regions). Patients dead on arrival, with head AIS 4 6, or with any missing data were excluded from our study. Demographic data (age, gender, injury severity score [ISS], AIS, Glasgow Coma Scale [GCS] score, ethnicity [White, African American, Hispanic, Asian, American Indian, and other], insurance status) and
1108
No. 10
HEALTH CARE INSURANCE AND BRAIN INJURY OUTCOMES
outcome data (hospital and intensive care unit length of stay [LOS] and mortality) were examined for all patients. Patients were considered uninsured if their payment status was ‘‘none’’ or ‘‘self pay’’ and considered insured for all others (Medicaid, Medicare, worker’s compensation, etc). Statistical Analysis
Insured patients were compared with their uninsured counterparts with respect to demographic and outcome data. Categorical variables were compared by the x2 or Fisher’s exact test. Numerical variables were compared by the t test (normal distribution) or the Wilcoxon rank sum test (nonnormal distribution). Multivariable logistic regression was used to assess factors related to the risk of in-hospital mortality. Adjusted odds ratios (AOR) as well as their 95 per cent confidence intervals were calculated. An adjusted P value < 0.05 was considered statistically significant. Descriptive statistics were summarized using raw percentages, means, standard deviation, in addition to, odds ratio and confidence intervals. All statistical analysis was performed using SAS, version 9.1 (SAS Institute, Cary, North Carolina). This study was determined to be exempt from institutional review board approval by the Institutional Review Board of the Cedars-Sinai Medical Center. Results
A total of 52,344 isolated moderate to severe TBI patients matched inclusion criteria and were included for analysis. Blunt injury was the most common cause of TBI in both groups (96.6%). Of the total patients, 70 per cent were male, 76 per cent were White, and the overall mortality rate was 9.1 per cent. When stratified by race, African Americans had a significantly higher rate of mortality when compared with Hispanics (8.9% vs 7.6%, P 4 0.02). When compared with Whites, Hispanics had a lower rate of mortality (9.2% vs 7.6%, P 4 0.0003). Eighty per cent of the patients were found to have some form of insurance. In comparing demographics and patient characteristics (Table 1), insured TBI patients were: older (46.1 ± 22.4 vs 37.3 ± 16.3 years, P < 0.0001), more likely to be female (32.5% vs 20.3%, P < 0.0001), more severely injured (ISS $ 16: 78.4% vs 74.4%, P < 0.0001) and had a higher GCS (11.1 ± 4.9 vs 10.9 ± 5, P < 0.0001) when compared with their uninsured counterparts. Outcome data (Table 1) revealed that insured TBI patients had a longer hospital LOS (11.8 ± 16 vs 10.7 ± 14.5 days, P < 0.0001), intensive care unit LOS (6.0 ± 9.4 vs 5.1 ± 7.6 days, P < 0.0001), and had a significantly higher overall mortality (9.3% vs 8.0%, P < 0.0001) compared with the uninsured. To determine
?
Alban et al.
1109
TABLE 1. Demographic and Outcome Data Comparing Insured to Uninsured Isolated TBI Patients Number (%) Age (years) SBP $ 90 Male GCS GCS # 8 ISS ISS $ 16 Intensive care unit LOS (days) Hospital LOS (days) Mortality Mortality Head AIS 3 Mortality Head AIS 4 Mortality Head AIS 5
Insured
Uninsured
P value
41,711 (79.7%) 46.1 ± 22.4 140 ± 29.6 67.5% 11.1 ± 4.9 30.4% 22.3 ± 10.2 78.4% 6.0 ± 9.4
10,633 (20.3%) 37.3 ± 16.3 137 ± 27.3 79.7% 10.9 ± 5 32.0% 21.2 ± 9.8 74.4% 5.1 ± 7.6
