Predictors of Insurance Denial with and without Prior Authorization in Patients Undergoing Spine Surgery: A Year-Long, Single-Center Cohort Analysis.

Abstract

Insurance prior authorization (PA), initially intended to curb healthcare costs and wasteful spending, has become a growing regulatory barrier to timely spine surgery. Yet, the process of PA and drivers of coverage denials remain elusive. We present a one-year review of insurance referrals for spine surgery at a single academic, tertiary care center to identify predictors of PA and ultimately coverage approval and denial. We retrospectively reviewed 740 adult patients referred for spine surgery between June 2023 and March 2025 at our single academic medical center in Florida. Data analyzed included demographics, insurance type (private vs. public), insurance provider, clinical severity (e.g., myelopathy, cord compression), and authorization outcomes. Univariate and Multivariate statistical analysis identified predictors of denial both with and without PA. Mean patient age was 66.8 years (54% male) with 40.4% of patients having public (Medicare) and 59.6% having private insurance. A majority of patients required PA (499, 67.4%). Of the total cohort, 45 (6.1%) of patients were ultimately denied coverage. Presence of neurologic deficit, myelopathic signs, cord compression or cord signal change on imaging, and prior trial of conservative management did not significantly predict need for PA or insurance coverage. Payor type (public vs. private and type of private insurer) was significantly associated with need for prior authorization and insurance outcome. Need for PA resulted in an average 14-day delay to final insurance decision and 11-day delay to spine surgery compared to patients who did not require PA (p<0.001). This single institution study suggests there may be other factors payors consider when making insurance decisions that are not directly tied to traditional clinical indicators of surgical necessity. Public versus private insurance as well as type of payor amongst patients with private insurance appear to be correlated with need for PA and insurance denial. Need for PA does significantly increase time to surgery for patients who must first undergo that process.