Preoperative Behavioral Health, Opioid, and Antidepressant Utilization and 2-year Costs After Spinal Fusion-Revelations From Cluster Analysis.

Study Design: Retrospective administrative claims database analysis.

Objective: Identify distinct presurgery health care resource utilization (HCRU) patterns among posterior lumbar spinal fusion patients and quantify their association with postsurgery costs.

Summary Of Background Data: Presurgical HCRU may be predictive of postsurgical economic outcomes and help health care providers to identify patients who may benefit from innovation in care pathways and/or surgical approach.

Methods: Privately insured patients who received one- to two-level posterior lumbar spinal fusion between 2007 and 2016 were identified from a claims database. Agglomerative hierarchical clustering (HC), an unsupervised machine learning technique, was used to cluster patients by presurgery HCRU across 90 resource categories. A generalized linear model was used to compare 2-year postoperative costs across clusters controlling for age, levels fused, spinal diagnosis, posterolateral/interbody approach, and Elixhauser Comorbidity Index.

Results: Among 18,770 patients, 56.1% were female, mean age was 51.3, 79.4% had one-level fusion, and 89.6% had inpatient surgery. Three patient clusters were identified: Clust1 (n = 13,987 [74.5%]), Clust2 (n = 4270 [22.7%]), Clust3 (n = 513 [2.7%]). The largest between-cluster differences were found in mean days supplied for antidepressants (Clust1: 97.1 days, Clust2: 175.2 days, Clust3: 287.1 days), opioids (Clust1: 76.7 days, Clust2: 166.9 days, Clust3: 129.7 days), and anticonvulsants (Clust1: 35.1 days, Clust2: 67.8 days, Clust3: 98.7 days). For mean medical visits, the largest between-cluster differences were for behavioral health (Clust1: 0.14, Clust2: 0.88, Clust3: 16.3) and nonthoracolumbar office visits (Clust1: 7.8, Clust2: 13.4, Clust3: 13.8). Mean (95% confidence interval) adjusted 2-year all-cause postoperative costs were lower for Clust1 ($34,048 [$33,265-$34,84]) versus both Clust2 ($52,505 [$50,306-$54,800]) and Clust3 ($48,452 [$43,007-$54,790]), P < 0.0001.

Conclusion: Distinct presurgery HCRU clusters were characterized by greater utilization of antidepressants, opioids, and behavioral health services and these clusters were associated with significantly higher 2-year postsurgical costs.

Level Of Evidence: 3.