1518. Comparing different chronic preoperative opioid use definitions on outcomes after spine surgery

Authors: Inamullah Khan; Emily R. Oleisky, BS; Jacquelyn S. Pennings, PhD; Jeffrey Hills; Ahilan Sivaganesan, MD; Richard Call, BS; Clinton J. Devin, MD; Kristin R. Archer (Nashville, TN)

Introduction: Most spine studies rely solely on opioid duration to stratify patients into preoperative risk categories, with no consensus on the definition of chronic preoperative opioid use. We aim to compare the established definitions of chronic opioid use relying on duration and/or dosage, including the CDC-guideline, in patients undergoing spine surgery. Methods: The study cohort consisted of 2,373 patients who underwent elective spine surgery for degenerative conditions between January,2011 and February,2017. The patients’ opioid data was extracted from the Tennessee Controlled Substance Monitoring Database and prospective clinical data (patient-reported satisfaction[NASS-Satisfaction Scale], disability[Oswestry/Neck Disability Index], and pain[Numeric Rating Scale]) from a single-center spine registry. Six different preoperative chronic opioid use variables were created based on the number of times a prescription was filled and/or daily morphine milligram equivalent for the one year before surgery. Multivariable regression models were used to compare chronic preoperative opioid use definitions by postoperative outcomes, adjusting for type of surgery. Results: Chronic preoperative opioid use was reported in 470(19.8%) to 725(30.6%) patients, depending on definition. The Edlund definition, accounting for duration and dosage, had the highest predictive ability for postoperative opioid use(77.5%), followed by Schoenfeld(75.7%), CDC guideline(72.6%), and Svendsen(59.9-72.5%) definitions. A combined Edlund and Schoenfeld duration and dosage definition in post-hoc analysis, that included 3- and 6-month duration cut-offs, performed the best overall(C-index=78.4%). Both Edlund and Schoenfeld definitions explained similar amounts of variance in clinical outcomes(4.2-8.5%). Svendsen definitions and the CDC guideline demonstrated poorer performance for patient-reported outcomes(1.4-7.2%). Conclusion: The Edlund definition is recommended for identifying patients at highest risk for postoperative opioid use. When dosage is unavailable, the Schoenfeld definition is a reasonable choice with similar predictive ability. For PROs, either the Edlund or Schoenfeld definition is recommended. Future work should consider combining dosage and duration, with 3- and 6-month cutoffs, into chronic opioid use definitions.