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

ABSTRACT

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.