Implementation of a Statewide Morphine Milliequivalent Prescribing Cutoff in Lumbar Fusion Surgery: A Michigan Spine Surgery Improvement Collaborative (MSSIC) Study

Introduction: Post-operative analgesia for lumbar fusion patients represents a challenge for surgeons as opiate medications take a primary role but run the risk of creating long-term opioid users. Our prior work has identified that continued opioid use at 90 days post-operative was a significant risk factor for continued opioid use at 1 and 2 years for patients undergoing lumbar fusion spine surgery. Thus, we set out to implement a statewide Morphine Milliequivalent (MME) post-operative prescribing cutoff. We aim to compare outcomes between opioid naïve patients based on whether they are prescribed opiates in compliance with our mandated threshold.

Methods: The Michigan Spine Surgery Improvement Collective (MSSIC) database was utilized to identify patients who underwent elective lumbar fusion after prescribing guidelines went into effect. We currently mandate 80% of opiate naïve patients undergoing 1 or 2-level lumbar fusion be prescribed 320 MME (45.7 daily/MME) or less over 7-days. Patients were grouped based on postoperative MME (≤320 vs. >320). Outcomes collected include opioid use, patient reported outcomes including MCID in pain, rate of return to work, and readmissions.

Results: A total of 4,817 patients were included in this study, with a mandate compliance rate of 81.4%. Patients receiving ≤320 MME had significantly lower opioid use at 90 days (OR 0.56, CI 0.45-0.70, p< 0.001) compared to those receiving >320 MME. There was also a trend toward lower risk of 1-year opiate use (OR 0.71, CI 0.49-1.03, p=0.069). No significant differences were observed in patient satisfaction at 90 days or one year. Additionally, MCID outcomes for back and leg pain, return to work, readmission rates, and ED visits did not differ significantly between the two groups.

Conclusion : Patients receiving MME ≤320 following lumbar fusion surgery had significantly lower opioid use at 90-days with a trend toward lower 1-year use. In addition, there was not a difference in readmission, ED utilization, or patient satisfaction which demonstrated that judicious opiate prescribing for lumbar fusions is feasible without unintended consequences.