Impact of Social Vulnerability Index Characteristics on Outcomes after Posterior Cervical Decompression and Fusion

Introduction: While patient demographics, surgical techniques, and comorbidities have been studied as risk factors for postoperative outcomes after posterior cervical decompression and fusion (PCDF), there is little research investigating the impact of social determinants of health (SDH) on PCDF outcomes. In this study, we used Social Vulnerability Index (SVI) variables to approximate various aspects of SDH and quantify their impact on PCDF outcomes.

Methods: Patients who underwent PCDF from 2006 to 2023 for degenerative cervical disease were identified from the electronic medical record at a multisite academic center. Numerous clinical variables including demographics, pre-operative comorbidities, and postoperative complications were included. Five patient SVI characteristics—socioeconomics, household characteristics, ethnic minority status, transportation, and overall SDH status—were assessed from 0-1, with 1 representing high vulnerability. A logistic regression model was run with SVI and clinical predictors as the independent variables and 90-day readmission as the dependent variable.

Results: A total of 1050 patients were included with an average age of 65 and BMI of 28. Average SVI values ranged from 0.28 to 0.54, with the highest level of vulnerability among household characteristics—including crowded housing—and the lowest among socioeconomic status. The strongest predictors of 90-day readmission included post-operative acute kidney injury (Est Effect = 1.24, p < .001), surgical site infection (Est Effect = 0.98, p < .01), and DVT (Est Effect = 0.84, p < .01). Of all the SDH variables included, socioeconomic status had the largest estimate effect, but did not reach statistical significance (Est Effect = 1.50, p < 0.1). Many clinical variables displayed a statistically significant relationship with 90-day readmission, while none of the SVI variables had a p-value <.05.

Conclusion : Post-operative acute kidney injury, surgical site infection, and DVT were the strongest predictors of 90-day readmission in this study, and socioeconomic status showed a slight trend towards significance in predicting 90-day readmission. Larger cohorts are needed to further validate these findings.