Use of the LACE plus index to predict readmissions after single-level lumbar fusion

OBJECTIVE Spinal fusion is one of the most common neurosurgical procedures. The LACE (length of stay, acuity of admission, Charlson Comorbidity Index [CCI] score, and emergency department [ED] visits within the previous 6 months) index was developed to predict readmission but has not been tested in a large, homogeneous spinal fusion population. The present study evaluated use of the LACE+ score for outcome prediction after lumbar fusion. METHODS LACE+ scores were calculated for all patients (n = 1598) with complete information who underwent single-level, posterior-only lumbar fusion at a single university medical system. Logistic regression was performed to assess the ability of the LACE+ score as a continuous variable to predict hospital readmissions within 30 days (30D), 30-90 days (30-90D), and 90 days (90D) of the index operation. Secondary outcome measures included ED visits and reoperations. Subsequently, patients with LACE+ scores in the bottom decile were exact matched to the patients with scores in the top 4 deciles to control for sociodemographic and procedural variables. RESULTS Among all patients, increased LACE+ score significantly predicted higher rates of readmissions in the 30D (p < 0.001), 30-90D (p = 0.001), and 90D (p < 0.001) postoperative windows. LACE+ score also predicted risk of ED visits at all 3 time points and reoperations at 30-90D and 90D. When patients with LACE+ scores in the bottom decile were compared with patients with scores in the top 4 deciles, higher LACE+ score predicted higher risk of readmissions at 30D (p = 0.009) and 90D (p = 0.005). No significant difference in hospital readmissions was observed between the exact-mtched cohorts. CONCLUSIONS The present results suggest that the LACE+ score demonstrates utility in predicting readmissions within 30 and 90 days after single-level lumbar fusion. Future research is warranted that utilizes the LACE+ index to identify strategies to support high-risk patients in a prospective population.