Incidence and Risk Factors for Chronic Postoperative Opioid Use After Major Spine Surgery: A Cross-Sectional Study With Longitudinal Outcome

BACKGROUND: Chronic opioid use is a significant public health concern. Surgery is a risk factor for developing chronic opioid use. Patients undergoing major spine surgery frequently are prescribed opioids preoperatively and may be at risk for chronic opioid use postoperatively. The aim of this study was to investigate the incidence of and perioperative risk factors associated with chronic opioid use after major spine surgery. METHODS: The records of patients who underwent elective major spine surgery at the University of Virginia between March 2011 and February 2016 were retrospectively reviewed. The primary outcome was chronic opioid use through 12 months postoperatively. Demographic data, medical comorbidities, preoperative pain scores, and medication use including daily morphine-equivalent (ME) dose, intraoperative use of lidocaine and ketamine, estimated blood loss, postoperative pain scores and medication use, and postoperative opioid use were collected. Logistic regression models were used to examine factors associated with chronic opioid use. RESULTS: Of 1477 patient records reviewed, 412 patients (27.9%) were opioid naive and 1065 patients (72.3%) used opioids before surgery. Opioid data were available for 1325 patients, while 152 patients were lost to 12-month follow-up and were excluded. Of 958 preoperative opioid users, 498 (52.0%) remained chronic users through 12 months. There was a decrease in opioid dosage (mg ME) from preoperative to 12 months postoperatively with a mean difference of -14.7 mg ME (standard deviation, 1.57; 95% confidence interval [CI], -17.8 to -11.7). Among 367 previously opioid-naive patients, 67 (18.3%) became chronic opioid users. Factors associated with chronic opioid use were examined using logistic regression models. Preoperative opioid users were nearly 4 times more likely to be chronic opioid users through 12 months than were opioid-naive patients (odds ratio, 3.95; 95% CI, 2.51-6.33; P < .001). Mean postoperative pain score (0-10) was associated with increased odds of chronic opioid use (odds ratio for a 1 unit increase in pain score 1.25, 95% CI, 1.13-1.38; P < .001). Use of intravenous ketamine or lidocaine was not associated with chronic opioid use through 12 months. CONCLUSIONS: Greater than 70% of patients presenting for major spine surgery used opioids preoperatively. Preoperative opioid use and higher postoperative pain scores were associated with chronic opioid use through 12 months. Use of ketamine and lidocaine did not decrease the risk for chronic opioid use. Surveillance of patients for these factors may identify those at highest risk for chronic opioid use and target them for intervention and reduction strategies.