This retrospective study of emergent hemorrhagic stroke patients found increased odds of in-hospital mortality for dual-eligible patients compared to no-charge patients and higher odds of complication (any) for dual-eligible patients compared to Medicaid and privately insured patients. Notably, dual-eligible patients had decreased odds of favorable discharge (home/home with services) compared to all other groups. Regarding secondary outcomes, dual-eligibles had increased odds of being in a higher Clavien-Dindo Classification grade compared to Medicaid and privately insured patients. Interestingly, dual-eligible had decreased hospital length of stay compared to Medicaid patients and deceased inflation-adjusted admission costs compared to all other insurance groups. To the best of our knowledge, our study is the first to focus on and characterize dual-eligible patient outcomes after emergent hemorrhagic stroke.
The present study found increased odds of in-hospital mortality among dual-eligibles compared to no-charge patients after adjustment, but no difference when compared to Medicare and Medicaid patients. Interestingly, James et al.  and Lai et al.  found that mortality risk was higher for hemorrhagic stroke patients with Medicaid, Medicare, and no insurance, compared to Private insurance . Additionally, Shen et al.  found that out of all insurance groups, uninsured patients had the highest mortality risk for hemorrhagic strokes with a 24% higher mortality risk for uninsured compared to privately insured patients. Some of these findings may be explained by differences in treatment allocation by insurance status. For example, Hobson et al.  reported that mortality was more than twice as likely for patients with no surgical treatment after subarachnoid hemorrhage compared to those who received surgery. The same study found Medicare patients were significantly less likely to receive surgical treatment. McCutcheon et al.  found a similar finding where uninsured patients demonstrated both a reduced likelihood of receiving a craniotomy for intracranial hematomas and an increased risk-adjusted mortality rate relative to insured patients.
The lack of difference between mortality rates for dual-eligible compared to Medicare patients is likely explained by the similar ages in both populations. With increased age as a risk factor for mortality, it is important to note that Medicare and dual-eligible patients in our study were on average older than all other groups . Additionally, Medicare patients in our study had the second-highest proportion of patients characterized as extreme APR-DRG Risk of Mortality signaling increased comorbidities. The non-significant difference between mortality rates for dual-eligible compared to Medicaid patients is likely multifactorial but is supported by the finding that the socioeconomic status of patients can influence mortality risk after stroke. For example, Kapral et al.  found that each $10,000 increase in median neighborhood income was associated with a 9% reduction in the hazard of death at 30 days for acute stroke patients.
Regarding the relationship between complications and insurance status, one study of traumatic brain injury patients by Schiraldi et al.  found that Medicaid patients were 1.78 times more likely to experience complications than commercially insured patients. Additionally, specific to subarachnoid hemorrhage, Dasenbrock et al.  found that Medicaid payer status was an independent predictor of developing Clostridium difficile infection which has been associated with increased hospital stay and a nonroutine hospital discharge. These results are consistent with our study, which found a higher incidence of complications in dual-eligible patients compared to privately insured patients. However, our study also found that dual-eligibles had significantly higher odds of complications compared to Medicaid, with dual-eligibles having the highest proportion of complications.
Overall, our study found significantly decreased odds of favorable discharge (home/home with services) among dual-eligibles compared to all other insurance groups. Notably, dual-eligibles in our study experienced increased odds of complications, which may in part explain this trend. A systematic review analyzing predictors of discharge location for patients post-traumatic brain injury reported increasing age, white and non-Hispanic race/ethnicity, insurance coverage, and more severe injury as predictors of discharge to a setting with rehabilitation services versus discharge to home . Results of the James et al,  analysis demonstrated that both Medicare and Medicaid hemorrhagic stroke patients were less likely to be discharged home in comparison to privately insured individuals. Conversely, Lai et al.  found that Medicaid and uninsured patients had a reduced odd of non-routine discharge despite longer hospital stays. A study by Strickland et al.  reported that when comparing patients treated for subarachnoid hemorrhage in a university hospital with a safety net county hospital, the safety net county hospital patients were 3.73 times more likely to be discharged with poor modified Rankin Scale scores and 3.08 times more likely to be discharged with poor Glasgow Outcome Scale scores. This finding supports a role for socioeconomic factors to affect discharge outcome and may help explain why the dual-eligible patients in our study, beneficiaries of public insurance plans (specifically Medicare plus Medicaid), had significantly decreased odds of discharge to home than all other beneficiaries.
Despite increased odds of complications and higher Clavien-Dindo Classifications among dual-eligible patients, our study found significantly shorter lengths of stay among dual-eligible beneficiaries compared to Medicaid patients. One possible explanation for this is the increased availability of skilled nursing facilities for dually insured patients compared to patients solely insured by Medicaid. Patients with Medicaid may run into issues with insurance eligibility at assisted living and skilled nursing facilities which may prolong the discharge process, thus increasing their overall length of stay. Results of a retrospective analysis by Fargen et al.  demonstrated shorter lengths of stay for privately insured patients therefore perhaps highlighting increased access to rehabilitation and skilled nursing facilities compared to Medicaid patients.
Limitations: The limitations of the present study include a lack of more nuanced insurance information and a follow-up period limited to prior to 2011. Given the limited insurance information provided, the authors designated anyone with both Medicare and Medicaid insurance as dual-eligible however, there is a need for follow-up studies looking at other insurance types such as individuals with both Medicare and private insurance (Medicare Advantage). Lastly, due to a lack of dual-insurance reporting in the National Inpatient Sample beyond the year 2011, we were unable to ascertain dual-eligible status beyond this year. However, it is important to note that the dual-eligible population has since increased with an average annual growth rate of 2.9%, thus providing continual relevance to our analysis [28,29]. Nonetheless, additional studies are warranted to better understand the impact of dual-eligible status on hemorrhagic stroke outcomes.