Independent Risk Factors for Opioid Refills at 31-60 and 61-90 Days After Spine Surgery: A Retrospective Cohort Study

Objective: To identify independent factors associated with opioid refills at 31-60 days and 61-90 days after discharge from spine surgery and to propose a screening marker for high-risk patients. Background: Although the 2-3 months following surgery are critical for the transition from short-term to persistent postsurgical opioid use, little is known about opioid refills during this period. Methods: This retrospective cohort study included 11,087 adult opioid-naive and non-opioid-naive patients who underwent spine surgery and were discharged between January 2017 and December 2023. Data were analyzed using multiple logistic and linear regressions and Fisher exact test. Results: Of the patients, 25.4% and 14.8% received opioid refills at 31-60 days and 61-90 days post-discharge, respectively. Among the independent risk factors, an opioid refill at 31-60 days was the strongest predictor of a refill at 61-90 days (aOR 6.71, 95% CI 5.90-7.65), regardless of preoperative opioid use, cervical or lumbar procedures, or surgical service. In fact, refill rates at 61-90 days were linearly correlated with those at 31-60 days (p < 0.0001, slope = 0.73). A refill at 31-60 days predicted a refill at 61-90 days with a negative predictive value (NPV) of 94.3% and a positive predictive value of 41.5%, with consistently high NPVs across subgroups defined by preoperative opioid use, surgical procedure, or surgeon. Moreover, a refill at 1-30 days was associated with increased risks of refills at both 61-90 days (aOR 3.16, 95%CI 2.76-3.62) and 31-60 days (aOR 4.04, 95% CI 3.66-4.46) after discharge. Preoperative use of opioids, cannabis, and benzodiazepine, as well as the first postoperative pain score recorded on the hospital floor and a diagnosis of depression, were associated with increased odds of refills at both 31-60 and 61-90 days. In contrast, surgical procedures were largely not associated with refills at either time point. Conclusion: Each opioid refill prescription should be carefully managed after spine surgery to prevent subsequent refills. A refill at 31-60 days after discharge may serve as a simple and effective screening marker for identifying high-risk patients who could benefit from multimodal pain management through a transitional pain service (TPS) to mitigate further opioid use.