The Impact of Neighborhood Socioeconomic Disadvantage on Operative Outcomes after Single-Level Lumbar Fusion

Abstract

Introduction: The relationship between socioeconomic status and neurosurgical outcomes has been investigated with respect to insurance status or median household income, but few studies have considered more comprehensive measures of socioeconomic status. This study examines the relationship between Area Deprivation Index (ADI), a comprehensive measure of neighborhood socioeconomic disadvantage, and short-term postoperative outcomes after lumbar fusion surgery.

Methods: 1861 adult patients undergoing single-level, posterior-only lumbar fusion at a single, multihospital academic medical center were retrospectively enrolled. An ADI matching protocol was used to identify each patient's 9-digit zip code and the zip code-associated ADI data. Primary outcomes included 30- and 90-day readmission, emergency department visits, reoperation, and surgical complication. Coarsened exact matching was used to match patients on key demographic and baseline characteristics known to independently affect neurosurgical outcomes. Odds ratios (ORs) were computed to compare patients in the top 10% of ADI versus lowest 40% of ADI.

Results: After matching (n = 212), patients in the highest 10% of ADI (compared to the lowest 40% of ADI) had significantly increased odds of 30- and 90-day readmission (OR = 5.00, P < 0.001 and OR = 4.50, P < 0.001), ED visits (OR = 3.00, P = 0.027 and OR = 2.88, P = 0.007), and reoperation (OR = 4.50, P = 0.039 and OR = 5.50, P = 0.013). There was no significant association with surgical complication (OR = 0.50, P = 0.63).

Conclusions: Among otherwise similar patients, neighborhood socioeconomic disadvantage (measured by ADI) was associated with worse short-term outcomes after single-level, posterior-only lumbar fusion. There was no significant association between ADI and surgical complications, suggesting that perioperative complications do not explain the socioeconomic disparities in outcomes.

Keywords: Area deprivation index; Health disparities; Lumbar fusion; Social determinants of health; Socioeconomic status; Spinal fusion.