The Social Deprivation Index and lumbar spine surgery outcomes.

Abstract

Objective: The Social Deprivation Index (SDI) measures area-level social disadvantage. SDI values range from 0 (no distress/prosperous) to 100 (highest distress). This study investigated the association between SDI and lumbar spine surgery outcomes.

Methods: A retrospective cross-sectional study was performed using electronic health record data from a multihospital academic health system from 2017 to 2024. Eligible patients included adults who underwent lumbar fusion or decompression alone. The primary exposure of interest was the binary SDI (low distress [SDI < 50] vs high distress [SDI ≥ 50 and ≤ 100]). SDI was associated with the patient's zip code of residence. The associations between SDI category and pain reduction, physical function improvement, length of stay, and 30-day readmission were examined. Both unadjusted and adjusted regression models were created. Adjusted models included the following covariates: age, comorbidities, race, insurance, and surgery type. Multiple imputation by chained equations was used to impute missing values.

Results: The total sample included 7598 patients with 5139 in the low-SDI group and 2459 in the high-SDI group. SDI category was not significantly associated with the likelihood of pain reduction or physical function improvement after surgery. In the adjusted model, residence in a high-SDI area was significantly associated with extended length of stay (OR 1.21, 95% CI 1.07-1.36, p = 0.002). In the unadjusted model, patients from high-SDI areas were significantly more likely to experience 30-day readmission (OR 1.35, 95% CI 1.07-1.71, p = 0.01). In the adjusted model, this association was no longer statistically significant (OR 1.00, 95% CI 0.74-1.36, p ≥ 0.99).

Conclusions: Patients from high-SDI areas had similar pain and physical function outcomes compared to patients from low-SDI areas after lumbar spine surgery. High SDI was significantly associated with length of stay. This study highlights the need for interventions that address the unique needs of patients from low-resource settings to improve lumbar spine surgery outcomes.