Factors predicting opioid dependence in patients undergoing surgery for degenerative spondylolisthesis: analysis from the MarketScan databases.

OBJECTIVE The opioid crisis is identified as a national emergency and epidemic in the United States. The aim of this study was to identify risk factors associated with opioid dependence in patients undergoing surgery for degenerative spondylolisthesis (DS). METHODS The authors queried MarketScan databases to investigate the factors affecting postsurgery opioid use in patients with DS between 2000 and 2012. The outcome of interest was opioid dependence, which was defined as continued opioid use, > 10 opioid prescriptions, or diagnosis of or prescription for opioid dependence disorder in the period of 1 year before or 3-15 months after the procedure. Comparisons of outcomes were performed using nonparametric 2-group tests and generalized regression models. RESULTS A cohort of 10,708 patients was identified from the database. The median patient age was 61 years (interquartile range 54-69 years), and 65.1% were female (n = 6975). A majority of patients had decompression with fusion (n = 10,068; 94%) and underwent multilevel procedures (n = 8123; 75.9%). Of 10,708 patients, 14.85% (n = 1591) were identified as having opioid dependence within 12 months prior to the index surgical procedure and 9.90% (n = 1060) were identified as having opioid dependence within 3-15 months after the procedure. Of all the variables, prior opioid dependence (OR 16.29, 95% CI 14.10-18.81, p < 0.001) and younger age (1-year increase in age: OR 0.972, 95% CI 0.963-0.980, p < 0.001) were independent predictors of opioid dependence following surgery for DS. The use of fusion was not associated with opioid dependence following the procedure (p = 0.8396). Following surgery for DS, patients were more likely to become opioid independent than they were to become opioid dependent (8.54% vs 3.58%, p < 0.001). CONCLUSIONS The majority of patients underwent fusion for DS. Surgical decompression with fusion was not associated with increased risk of postsurgery opioid dependence in patients with DS. Overall, opioid dependence was reduced by 4.96% after surgery for DS. Prior opioid dependence is associated with increased risk and increasing age is associated with decreased risk of opioid dependence following surgery for DS.