Insurance disparities are associated with worse post-rehabilitation outcomes in gunshot vs. motor vehicle accident spinal cord injury: a retrospective cohort study

Abstract

Background

Spinal cord injuries (SCIs) resulting from gunshot wounds (GSWs) and motor vehicle accidents (MVAs) differ in mechanism, injury severity, and care pathways. Insurance coverage may further influence access to inpatient rehabilitation (IPR) and post-acute services, thereby affecting recovery trajectories. In the United States, MVA-related SCIs are frequently covered by no-fault auto insurance with broad benefits, whereas GSW-related SCIs are more commonly covered by Medicaid, which may limit rehabilitation duration and intensity. The objective of this study was to assess the association between insurance status and post-rehabilitation outcomes in patients with SCI due to GSWs compared with MVAs.

Methods

This Institutional Review Board (IRB)-approved retrospective cohort study included 40 patients with traumatic SCI treated at a single IPR center, including 20 GSW-related and 20 MVA-related SCIs, all with at least 1 year of follow-up. Demographic characteristics, insurance type, injury severity, and social determinants of health were collected, including Area Deprivation Index (ADI) and Social Vulnerability Index (SVI) scores. Primary outcomes included IPR length of stay (LOS), inpatient complications, and healthcare utilization [emergency department (ED) visits and hospital readmissions] within 1 year of discharge. Between-group comparisons were performed using independent t-tests.

Results

GSW patients were significantly younger than MVA patients (mean age 27.45 vs. 46.00 years, P<0.001) and were more frequently insured by Medicaid (85% vs. 45%, P=0.004). In contrast, auto insurance coverage was present in 50% of MVA patients and 0% of GSW patients (P<0.001). Neighborhood disadvantages were similar between groups (ADI 88.45 vs. 83.30, P=0.14; SVI 0.77 vs. 0.68, P=0.14). GSW patients had more severe neurologic injury, with lower mean American Spinal Injury Association (ASIA) scores (1.90 vs. 2.74, P=0.01), lower rates of surgical intervention (45% vs. 85%, P=0.004), and shorter IPR stays (32 vs. 46 days, P=0.004). GSW patients experienced more inpatient complications (6.35 vs. 4.80 per patient, P=0.03) and greater post-discharge healthcare utilization, including higher ED visits (1.60 vs. 0.50, P=0.01) and hospital readmissions (1.25 vs. 0.25, P=0.04) within 1 year.

Conclusions

Insurance disparities influence orthopedic surgical decision-making, IPR length, and complication burden in SCI patients. Patients with GSW-related SCIs, despite being younger, experienced more severe injuries, lower surgical intervention rates, and higher post-discharge healthcare utilization. These findings highlight the need for equitable access to spine surgery, rehabilitation, and follow-up care to optimize outcomes across trauma mechanisms.

Highlight box.

Key findings

• Gunshot wound (GSW) spinal cord injury (SCI) patients had shorter inpatient rehabilitation stays, higher complication rates, and greater post-discharge healthcare utilization than motor vehicle accident (MVA) SCI patients.

• A significantly greater share of GSW patients were insured by Medicaid, whereas MVA patients were more commonly covered by auto insurance.

What is known and what is new?

• Traumatic SCIs vary by mechanism, with penetrating SCIs more likely to be complete injuries and less often surgically treated than blunt-force SCIs.

• GSW patients have worse recovery trajectories linked to insurance disparities, even from similarly disadvantaged neighborhoods.

What is the implication, and what should change now?

• Limited Medicaid coverage may shorten rehab and increase readmissions for GSW SCI patients.

• Post-acute care access should be standardized to ensure comprehensive rehabilitation and follow-up, improving outcomes regardless of insurance.

Introduction

Spinal cord injuries (SCIs) represent a profoundly debilitating condition, with approximately 18,000 new cases occurring annually and an estimated 257,000 to 388,000 individuals living with an SCI nationwide (1). These injuries are broadly categorized as primary, resulting from direct mechanical force, or secondary, stemming from physiological responses to the initial injury (2). Traumatic injuries dominate as the most common cause of primary SCI, encompassing motor vehicle accidents (MVAs), falls, violence, sports injuries, and medical/surgical complications (1,2). While MVAs have been the leading cause of SCIs in the USA since at least 2015, accounting for 37.5% of cases, falls closely follow at 31.7%, and violent causes, predominantly gunshot wounds (GSWs), constitute 15.4% (1). Patients with SCIs frequently face complications such as urinary tract infections, pressure injuries, deep vein thrombosis, hypotension, and chronic pain (2). The severity of SCI is clinically classified using the American Spinal Injury Association Impairment Scale (ASIA A-E), which delineates the extent of complete or incomplete motor and sensory function loss (3).

Treatment for SCIs varies based on the injury type, ASIA severity, and associated non-spinal injuries. A retrospective review of National Spinal Cord Injury Statistical Center (NSCISC) patients from 1975 to 2015 by Goh et al. found that surgical intervention for GSW-related SCIs was associated with a 1.7 to 2.5 times greater chance of improving ASIA scores by 1 year post-operation (4). Roach et al. examined differences in treatment and outcomes between blunt-force SCIs (BSCIs), such as those from MVAs, and penetrating SCIs (PSCIs), such as GSWs, in a retrospective review from 1994 to 2015, and concluded that PSCIs were significantly more likely to present as complete injuries (ASIA A) compared to BSCIs (56.8% vs. 35.9% respectively; P<0.001) (5). Additionally, PSCI patients were significantly less likely to have undergone spine surgery (19.6% vs. 80.6% respectively; P<0.001) (5). Even after controlling for injury severity, patients with complete BSCIs showed greater improvement in their ASIA score 1 year post-injury (5). This suggests that individuals with complete SCIs due to MVAs may experience better outcomes than those with complete SCIs due to GSWs. Further research is needed to explore potential contributing factors, such as inequities in medicine, that may explain these differing outcomes and the lower rates of surgery observed for the PSCI group, despite evidence of neurofunctional improvement with surgical treatment.

While there are many factors that may contribute to this discrepancy, insurance coverage plays a significant role in healthcare utilization and outcomes (6,7). Insurance may determine a patient’s access to recovery tools such as inpatient rehabilitation (IPR) and additional medical costs. For instance, in Michigan, USA, MVA victims are typically covered by no-fault auto insurance, which often provides more extensive and lifetime coverage for injuries sustained during the accident (8). This can include long-term rehabilitation, adaptive equipment, personal attendant care, and ongoing medical care without co-pays (8).

Conversely, treatment for GSW injuries may often fall under Medicaid or other forms of health insurance, which may have different coverage limitations and requirements (9,10). In the United States, Medicaid provides government-funded health coverage for individuals and families with low income or qualifying disabilities. In Michigan, eligibility is primarily determined by income and disability status, with recent state expansions broadening access to include additional low-income adults. Medicaid, while crucial for low-income individuals, can vary significantly in services covered by state, and may have limitations on certain long-term care services, rehabilitation intensity, and access to specific specialists or durable medical equipment compared to no-fault auto insurance (8,9). These limitations could directly affect access to specialized treatments, comprehensive longer-term rehabilitation, and ultimately, a patient’s recovery trajectory and overall quality of life. The differing frameworks of these insurance types can lead to substantial disparities in the financial burden and accessibility of necessary post-acute care for SCI patients, potentially contributing to a cycle of complications and increased need for acute care services.

This study sought to examine the relationship between insurance status and outcomes following SCI caused by either a GSW or an MVA. We hypothesize that patients with GSW-related SCI will experience poorer outcomes and distinct patterns of healthcare utilization after discharge from IPR compared with those injured in MVAs, largely due to insurance-related disparities. Specifically, we anticipate that GSW patients will face higher complication rates and require more hospital readmissions and emergency department (ED) visits within the year after injury. We present this article in accordance with the STROBE reporting checklist (available at https://jss.amegroups.com/article/view/10.21037/jss-25-164/rc).

Methods

The Wayne State University Institutional Review Board (IRB) approved (No. IRB-24-08-7090) this retrospective pilot study which was conducted in accordance with the Declaration of Helsinki and its subsequent amendments, at the Rehabilitation Institute of Michigan (RIM), an affiliate of the Detroit Medical Center and Wayne State University School of Medicine. Given the retrospective nature of the study, use of existing medical records, and minimal risk to participants, the requirement for informed consent was waived by the IRB.

This study evaluated disparities in health outcomes and healthcare utilization between patients with SCIs secondary to GSWs, and MVAs. Patients were selected from a rehabilitation-focused SCI database at the RIM. All patients with at least 1 year of follow-up encounters were included. Patients with non-spinal acute surgical procedures were excluded to reduce confounding from polytrauma-related rehabilitation variability. Furthermore, all patients were confirmed to have at least one recorded visit occurring 1 year or more after discharge, ensuring a minimum follow-up duration of 1 year and minimizing missing data. The convenience sample included a total of 40 patients, with 20 patients in each cohort.

Demographic and clinical variables were extracted from the RIM’s electronic medical record database through a retrospective chart review. Social determinants of health (SDOH) were measured using the Area Deprivation Index (ADI), which quantifies neighborhood socioeconomic disadvantage, and the Social Vulnerability Index (SVI), which assesses a community’s resilience to external stressors and public health emergencies (11,12). Clinical characteristics included ASIA impairment scores from the International Standards for Neurological Classification of SCI (ISNCSCI) exam, and which spinal segments were involved. ASIA grades (A–E) were ordinally coded from 1 to 5 for comparison of impairment severity between groups. This transformation was not intended to represent a continuous or linear measure.

Primary outcomes included length of stay (LOS) at the RIM, complications occurring from the time of injury to discharge from IPR as documented by physicians, and healthcare utilization up to 1 year post-discharge. Healthcare utilization metrics included the number of ED visits, hospitalizations, and procedures per patient.

Statistical analysis

Descriptive statistics were used to summarize demographic, socioeconomic, clinical, and outcome variables. Continuous variables are reported as means with standard deviations and were compared between groups using independent two-sample t-tests. Categorical variables are reported as counts and percentages and were compared using Chi-squared or Fisher’s exact tests, as appropriate. Statistical significance was defined as a two-sided P value <0.05. Due to the pilot nature of the study and limited sample size, multivariable regression analyses were not performed. All statistical analyses were conducted using SPSS Statistics version 30 (IBM Corp., Armonk, NY, USA).

Results

Patient demographics and socioeconomic context

GSW patients were significantly younger compared to MVA patients (mean age 27.45 vs. 46.00 years, P<0.001). Both groups had similarly high levels of neighborhood disadvantage, with no significant differences in ADI (88.45 vs. 83.30, P=0.14) or SVI (0.77 vs. 0.68, P=0.14). Insurance status varied markedly. Significantly more GSW patients were covered by Medicaid (85% vs. 45%, P=0.004), while MVA patients more commonly had auto insurance (50% vs. 0%, P<0.001) or private insurance (45% vs. 10%, P=0.007) (Table 1).

Table 1. Demographics, social determinants of health, and insurance status.

Variable	Gunshot victims	MVA victims	P value
Age (years)	27.45 (5.49)	46.00 (15.09)	<0.001***
Social determinants of health
Area Deprivation Index	88.45 (13.23)	83.30 (15.80)	0.14
Social Vulnerability Index	0.77 (0.24)	0.68 (0.30)	0.14
Insurance type
Private (n=11)	2 [10]	9 [45]	0.007**
Medicare (n=1)	0 [0]	1 [5]	0.16
Medicaid (n=26)	17 [85]	9 [45]	0.004**
Auto (n=10)	0 [0]	10 [50]	<0.001***
Uninsured (n=1)	1 [5]	0 [0]	0.16

Data are presented as mean (standard deviation) or n [%]. **, P<0.01; ***, P<0.001. MVA, motor vehicle accident.

Injury severity and clinical presentation

GSW patients presented with lower ASIA impairment scores (1.90 vs. 2.74, P=0.01), indicating greater neurological and anatomical severity. The distribution of neurological injury levels was comparable between cohorts, with cervical injuries being most common (50% in both groups), followed by thoracic injuries (50% in GSW vs. 40% in MVA), and lumbar injuries least frequent (0% in GSW vs. 10% in MVA). Rates of surgical intervention differed significantly, with 45% of GSW patients undergoing surgery compared to 85% of MVA patients (P=0.004) (Table 2).

Table 2. Clinical characteristics and outcomes by injury mechanism.

Injury status	Gunshot victims (N=20)	MVA victims (N=20)	P value
ASIA Impairment Scale	1.90 (1.12)	2.74 (1.10)	0.01*
Spinal region
Cervical	10 [50]	10 [50]	N/A
Thoracic	10 [50]	8 [40]	N/A
Lumbar	0 [0]	2 [10]	N/A
Operation rate (%)	45 (0.51)	85 (0.37)	0.004**

Data are presented as mean (standard deviation) or n [%]. *, P<0.05; **, P<0.01. ASIA, American Spinal Injury Association; MVA, motor vehicle accident; N/A, not applicable.

Rehabilitation course

LOS at the RIM differed significantly between groups: GSW patients stayed an average of 32 days compared to 46 days for MVA patients (P=0.004). The results are shown in Figure 1.

Figure 1.

IPR length of stay (days) in MVA patients compared to GSW patients. This figure illustrates the significantly shorter length of stay for GSW patients in IPR when compared to MVA patients. Error bars represent 95% confidence intervals. Mean (days) refers to the average number of days spent in IPR per cohort. **, P<0.01. GSW, gunshot wound; IPR, inpatient rehabilitation; MVA, motor vehicle accident.

Complications

GSW patients experienced a notably higher complication burden throughout their IPR course. On average, they sustained 6.35 complications per patient compared with 4.80 among MVA patients (P=0.03), underscoring a substantially greater medical complexity. The most pronounced differences were observed in wound-related complications, with delayed wound healing occurring six times more frequently in the GSW cohort (0.60 vs. 0.10, P<0.001). GSW patients also demonstrated a higher frequency of percutaneous endoscopic gastrostomy (PEG) tube placement (0.05 vs. 0.00, P=0.04), reflecting increased nutritional or respiratory compromise. Other complications such as urinary tract infection, respiratory distress, and deep vein thrombosis trended higher among GSW patients, further supporting a pattern of elevated medical fragility in this group (Table 3).

Table 3. Incidence of 1-year complications after SCI in GSW cohort vs. MVA cohort.

Complication	GSW	MVA	P value
Total complication count	6.35±2.58	4.80±2.44	0.03*
Pressure ulcer	0.50±0.51	0.35±0.49	0.18
Wound healing delay	0.60±0.50	0.10±0.31	<0.001***
Tracheostomy	0.25±0.44	0.15±0.37	0.22
Pneumothorax	0.20±0.41	0.05±0.22	0.08
Pneumonia	0.05±0.22	0.15±0.37	0.15
Pulmonary embolism	0.05±0.22	0.10±0.31	0.28
Deep vein thrombosis	0.45±0.51	0.30±0.47	0.17
Urinary tract infection	0.65±0.49	0.40±0.50	0.06
Sepsis	0.25±0.44	0.15±0.37	0.22
Acute kidney injury	0.05±0.22	0.05±0.22	0.50
PEG tube placement	0.05±0.22	0.00±0.00	0.04*
Suprapubic catheter	0.00±0.00	0.10±0.31	0.08
Urinary retention	0.35±0.49	0.30±0.47	0.37
Anemia/hypotension	0.50±0.51	0.45±0.51	0.38
Respiratory distress	0.35±0.49	0.15±0.37	0.08
Adjustment disorder	0.75±0.44	0.65±0.49	0.25
Dysphagia	0.25±0.44	0.35±0.49	0.25
Bowel/bladder dysfunction	1.00±0.00	0.90±0.31	0.08
Reoperation	0.00±0.00	0.05±0.22	0.16

Data are presented as mean ± standard deviation. *, P<0.05; ***, P<0.001. GSW, gunshot wound; MVA, motor vehicle accident; PEG, percutaneous endoscopic gastrostomy; SCI, spinal cord injury.

Post-discharge healthcare utilization

Within 1 year post-discharge, GSW patients had significantly higher healthcare utilization. They had more ED visits (1.60 vs. 0.50, P=0.01) and hospital readmissions (1.25 vs. 0.25, P=0.04) compared to MVA patients (Figure 2).

Figure 2.

Twelve-month healthcare utilization post-discharge from IPR. This figure illustrates the mean number of procedures, hospitalizations, and emergency department visits per patient, demonstrating significantly greater healthcare resource utilization in the GSW cohort. Error bars represent 95% confidence intervals. Mean (number of events) refers to the average number of events (procedures, hospitalizations, or emergency department visits) experienced by each cohort. *, P<0.05; **, P<0.01. GSW, gunshot wound; IPR, inpatient rehabilitation; MVA, motor vehicle accident.

Discussion

Insurance disparities have practical ramifications in the post-acute care of SCI patients. Limited or absent coverage can delay specialist consultation, restrict operative options, and constrain access to extended IPR, all of which are crucial for neurologic recovery after severe spinal injuries (13,14). In this study, although both groups came from neighborhoods with high social vulnerability, insurance coverage diverged sharply. 85% of GSW patients were insured by Medicaid compared to 45% of MVA patients, while 50% of MVA patients were covered by Michigan’s no-fault auto insurance. This divergence in payer type likely translated into meaningful differences in outcomes.

Medicaid’s lower reimbursement rates and stricter coverage limitations may be associated with the significantly shorter IPR stays observed in the GSW cohort. While shorter stays might suggest faster recovery, the increased burden of complications and higher post-discharge healthcare utilization among GSW patients, reflected in more ED visits and hospital readmissions, supports the interpretation that many were discharged prematurely. Medicaid’s restricted rehabilitation benefits may therefore place patients at risk of inadequate recovery, with downstream costs shifted toward safety-net hospitals that care for readmitted or uninsured patients (13,14). Furthermore, national data demonstrate that acute care lengths of stay for SCI have decreased from approximately 24 days in the 1970s to 11 days in 2016, while IPR stays have declined from about 98 to 35 days over the same period. This trend places greater pressure on IPR programs to achieve meaningful neurological and functional recovery in a shorter timeframe, underscoring the potential impact of the shorter stays observed in our GSW cohort (9).

In contrast, auto and private insurance, which were more common among MVA patients, often provide broader coverage for surgical intervention, advanced imaging, and outpatient therapies (14,15). This may facilitate longer rehabilitation stays, higher surgical intervention rates, and smoother transitions to follow-up care. These factors could potentially contribute to the lower complication rates and less frequent reliance on acute care after discharge. Despite being younger, GSW patients had more severe injuries, as reflected by lower ASIA scores on admission and a greater degree of spinal level involvement. Further, these injuries were likely compounded by systemic insurance barriers that limited access to optimal post-acute care. For orthopedic surgeons, these findings highlight how payer status can influence not only operative decision-making but also rehabilitation trajectories and long-term outcomes. Medicaid’s limited coverage may constrain access to essential spine procedures, wound management, and post-acute rehabilitation, whereas auto and private insurance often allow extended IPR and comprehensive follow-up. The result is a vicious cycle where PSCI patients may face more complications, inadequate recovery, and greater healthcare utilization, which can ultimately place a burden on trauma, orthopedic, and rehabilitation systems. Prior studies of traumatic injuries have described similar patterns, where disparities in insurance coverage are associated with worse long-term health outcomes and increased healthcare costs (14-16).

Importantly, this study is the first to concurrently examine insurance status, social disadvantage indices (ADI and SVI), inpatient complications, and post-discharge healthcare utilization following SCI, providing a multidimensional view of disparities not previously explored in this population. This study contributes to the literature by integrating both ADI and SVI as measures of neighborhood disadvantage while also analyzing detailed clinical and post-discharge data. Few existing studies include all these domains (1-3). Beyond differences in LOS, the markedly higher complication burden among GSW patients represents a key finding of this study, emphasizing how clinical course and insurance disparities may intersect to shape recovery trajectories. The higher complication burden observed in GSW patients, particularly wound healing delays, may reflect not only injury complexity but also delayed access to surgical and rehabilitative interventions, as well as postoperative wound care. These findings highlight the need for policymakers to reconsider how public insurance programs support spinal cord injury patients, particularly those with penetrating injuries. Standardizing benefits across payer types and ensuring access to timely surgical care, rehabilitation, and long-term follow-up may help close the outcome gaps identified in this study.

This study has limitations that must be noted. The small sample size (n=40) restricted statistical power and prevented the use of multivariable regression analysis to control potential confounders such as age and ASIA severity was not feasible. As such, these results should be interpreted as descriptive and hypothesis-generating, highlighting trends that merit validation in larger multicenter cohorts. As a single-center study conducted in Michigan, findings may not generalize to regions without a no-fault auto insurance system, where payer structures differ. The retrospective design also introduces the possibility of incomplete documentation, particularly for complications or follow-up visits outside the institution. Follow-up was limited to 1 year, which may underestimate longer-term disparities in outcomes and healthcare utilization. Additionally, while ADI and SVI were included as measures of social disadvantage, other unmeasured variables such as family support, employment, and community rehabilitation access were not captured and may play an influential role in one’s recovery trajectory. Insurance type was used as a proxy for resource availability, but differences in care pathways could also reflect institutional practices or provider decision-making, which this study could not fully assess. Future directions of this pilot study include analysis of larger cohorts with follow-up beyond 1 year to determine whether these disparities resolve, persist, or widen.

Conclusions

Although both groups came from similarly disadvantaged neighborhoods, patients with SCIs from GSWs had shorter rehabilitation stays, higher complication rates, and greater reliance on emergency and inpatient care within 1 year of discharge, compared to those injured in MVAs. These differences were closely linked to insurance type, with Medicaid coverage providing more limited resources than the auto and private insurance commonly held by MVA patients. While differences in neurologic level and injury completeness may also contribute to these disparities, the trends observed underscore that insurance-related factors may play a significant role in shaping recovery trajectories. These findings highlight the critical role of insurance in shaping post-acute recovery and emphasize the need for policy reforms that ensure timely access to surgical care, rehabilitation, and long-term follow-up, reducing disparities for patients most at risk.

Supplementary

The article’s supplementary files as

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Wayne State University Institutional Review Board (No. IRB-24-08-7090). Due to the retrospective study design and use of de-identified clinical data, the requirement for informed consent was waived by the Institutional Review Board.

Data Sharing Statement

Available at https://jss.amegroups.com/article/view/10.21037/jss-25-164/dss

jss-12-02-17-dss.pdf ^{(116.5KB, pdf)}

DOI: 10.21037/jss-25-164