1603. Insurance Status is Predictive of Postoperative Outcomes and Readmission Following Posterior Lumbar Fusion

Authors: Annie Arrighi-Allisan; Daniel Snyder, BS; Sean Neifert, BS; John Foote Jr., MD; Jonathan Rasouli, MD; Jonathan Gal; Brian Deutsch, BS; John Caridi, MD (New York, NY)


Posterior lumbar fusion (PLF) is performed to treat numerous spinal deformities, degenerative diseases, fractures, infections, and tumors. Insurance status has been implicated in poor outcomes for a variety of surgeries; however, its effect on outcomes following PLF has yet to be elucidated.


All PLF cases from 2008-2016 were obtained from a single institution. Demographic, comorbidity, and outcomes data were collected. Five cohorts were created by insurance status: commercial, Medicare, Medicaid, managed care, and uninsured. Groups were compared using bivariate analysis. Multivariate models were created controlling for age, sex, ASA status, and Elixhauser score for the following outcomes: in-hospital complication, prolonged length of stay (LOS), ICU stay, nonhome discharge, and unplanned readmission or ER visit within 30 and 90 days.


When compared to patients on commercial insurance, patients with Medicaid or Medicare had a significantly greater proportion of ASA designations >2 (45.89% and 52.91%, respectively, vs. 26.42%, both P<0.001). Patients on Medicare were more likely to experience an in-hospital complication (7.44% vs. 3%, P=0.0001), prolonged LOS (34.7% vs. 21.47%, P<0.0001), ICU stay (11.42% vs. 6.31%, P=0.0005), and nonhome discharge (43.62% vs. 12.01%, P<0.0001) than those with commercial insurance. Similarly, Medicaid patients were more likely to experience a prolonged LOS (35.29% vs. 21.47%, P=0.004) and nonhome discharge (29.41% vs. 12.01%, P<0.0001). Inequalities in postoperative outcomes persisted despite controlling for significant preexisting differences. Medicaid proved to be a risk factor for both 30-day readmission (OR=2.81, 95% CI: 0.84 – 9.36, P=0.0322) and 90-day ER visit (OR=2.38, 95% CI: 0.88 – 6.46, P=0.0302).


Our findings show a correlation between Medicare and Medicaid insurance and poorer postoperative outcomes following PLF. Disparities in outcomes may reflect broader social inequities or be commensurate with the standard of care received by patients with non-commercial insurance, perhaps due to lower perceived reimbursement rates.