Cost Implications of Insurance Associated Disparities in Post-Acute Traumatic Brain and Spinal Cord Injury Rehabilitation

Abstract

Background: Post-acute care after spinal cord injury (SCI) or traumatic brain injury (TBI) influences neurological function regained. Inpatient rehabilitation facilities (IRFs) have more intensive care and result in lower mortality and better functional outcomes compared to skilled nursing facilities (SNFs). This study sought to quantify inpatient rehabilitation access by insurance and estimate the cost implications. Methods: We conducted a retrospective observational cohort study utilizing 2015-2017 California Office of Statewide Health Planning and Development database of injured adults with SCI and/or TBI. The primary predictor was insurance status. The outcome was discharge destination [home, IRFs, SNFs, long-term acute care (LTAC)] modeled using multivariable multinomial mixed-effects logistic regression controlling for age, diagnosis, Weighted Elixhauser Comorbidity Index, and New Injury Severity Score. Cost of care for discharge to IRFs versus SNFs was estimated by adjusted quantile regression. Cost simulation predicted the adjusted cost difference if all publicly insured participants were discharged to an IRF. Results: We identified 83,230 patients with an injury mechanism and a primary acute care hospitalization diagnosis of TBI (90.9%), SCI (8.3%) or both (0.8%) who were discharged to an IRF, SNF, LTAC or home. Publicly insured patients were more likely than privately insured patients to go to SNFs versus IRFs (OR: 2.17, 95%CI [2.01-2.34]). Sub-group analysis of 6,416 participants showed an adjusted median total cost difference of $18,461 (95%CI [$5,908-$38,064]) and adjusted cost-per-day of the post-acute encounter of $1,045 (95%CI [$752-$2,399]) higher for discharge to IRFs versus SNFs. Cost simulation demonstrated an additional adjusted cost of $364M annually for universal IRF access for the publicly insured. Conclusions: Publicly insured SCI and TBI Californians are less frequently discharged to IRFs compared to their privately insured counterparts resulting in a lower short-term cost of care. However, the consequences of decreased intensive rehabilitation utilization in terms of functional recovery and long-term cost implications require further investigation. Abbreviations and Acronyms: SCI, spinal cord injury; TBI, traumatic brain injury; IRF, inpatient rehabilitation facility; SNF, skilled nursing facility; OSHPD, Office of Statewide Health Planning and Development; ICD-9/10-CM, International Classification of Disease, Ninth and Tenth Revisions, Clinical Modifications; LTAC, long-term care facility; NISS, New Injury Severity Score; AHRQ, Agency for Healthcare and Research Quality; ACA, Affordable Care Act