Insurance-Based Disparities in Stroke Center Access in California: A Network Science Approach

Abstract

Background: Our objectives were to determine whether there is an association between ischemic stroke patient insurance and likelihood of transfer overall and to a stroke center and whether hospital cluster modified the association between insurance and likelihood of stroke center transfer. Methods: This retrospective network analysis of California data included every nonfederal hospital ischemic stroke admission from 2010 to 2017. Transfers from an emergency department to another hospital were categorized based on whether the patient was discharged from a stroke center (primary or comprehensive). We used logistic regression models to examine the relationship between insurance (private, Medicare, Medicaid, uninsured) and odds of (1) any transfer among patients initially presenting to nonstroke center hospital emergency departments and (2) transfer to a stroke center among transferred patients. We used a network clustering method to identify clusters of hospitals closely connected through transfers. Within each cluster, we quantified the difference between insurance groups with the highest and lowest proportion of transfers discharged from a stroke center. Results: Of 332 995 total ischemic stroke encounters, 51% were female, 70% were ≥65 years, and 3.5% were transferred from the initial emergency department. Of 52 316 presenting to a nonstroke center, 3466 (7.1%) were transferred. Relative to privately insured patients, there were lower odds of transfer and of transfer to a stroke center among all groups (Medicare odds ratio, 0.24 [95% CI, 0.22–0.26] and 0.59 [95% CI, 0.50–0.71], Medicaid odds ratio, 0.26 [95% CI, 0.23–0.29] and odds ratio, 0.49 [95% CI, 0.38–0.62], uninsured odds ratio, 0.75 [95% CI, 0.63–0.89], and 0.72 [95% CI, 0.6–0.8], respectively). Among the 14 identified hospital clusters, insurance-based disparities in transfer varied and the lowest performing cluster (also the largest; n=2364 transfers) fully explained the insurance-based disparity in odds of stroke center transfer. Conclusions: Uninsured patients had less stroke center access through transfer than patients with insurance. This difference was largely explained by patterns in 1 particular hospital cluster.

Stroke Systems of Care 2.0: Moving Toward Definability, Accountability, and Equity

“…In California, for example, a network analysis identified that insurance-based disparities in access to stroke center care were explained by one particular cluster of hospitals and its transfer patterns. 12 Rapid consolidation of the health care system, brought about by widespread hospital mergers and acquisitions, hospital closures, and new employment models for physicians (eg, large health systems, corporations, private equity-backed staffing companies), has resulted in dramatic changes to where care is available. 13 As yet, consolidation has been associated with few measurable benefits to patients but with increased overall costs.…”

“…In California, for example, a network analysis identified that insurance-based disparities in access to stroke center care were explained by one particular cluster of hospitals and its transfer patterns. 12…”

Reframing Our Approach to Disparities in Cardiac Arrest Outcomes: The Importance of Systems and Structures in Patient Outcomes

“…Unfortunately, current evidence suggests that these transfer systems are not configured to ensure equitable access for patients and may, in fact, further exacerbate these disparities. 18 , 19 …”