“Decompression and fusion for degenerative spondylolisthesis is associated with reduced risk of opioid dependency”, says Mayur Sharma (Department of Neurosurgery, University of Louisville, Louisville, USA), summarising his latest research, recently published in the Journal of Neurosurgery: Spine. The study reports that degenerative spondylolisthesis patients are more likely to have a dependency on opioid medications before surgery than afterward.
In the midst of the US opioid epidemic, identified as a national emergency, Sharma and colleagues set out to investigate the risk factors for the development of opioid dependence in these patients by analysing data from MarketScan databases. In 2015, opioid overdose was cited as a cause of more than 33,000 deaths in the USA alone.
A large proportion of opioid addiction can be traced back to the misuse of physician-prescribed medications initially provided for the management of acute or chronic pain. The lower back is a common site of pain—approximately 80% of adults experience low back pain at some point in their lives. Low back pain has been cited as the leading global cause of disability.
Opioid dependence reduced after surgery
After evaluating the impact of surgery, patient age and sex, comorbidities, and type of medical insurance held by the patients, the authors determined the following applied to patients who underwent surgery to treat degenerative spondylolisthesis:
- There was an association between surgical decompression with fusion and a decreased risk of postoperative opioid dependence. In this study, the opioid dependence was reduced by 5% after surgery for degenerative spondylolisthesis (90.1% patients were opioid independent following surgery, an increase from 85.15% prior to surgery).
- Preoperative opioid dependence was associated with an increased risk of postoperative opioid dependence.
- Increased patient age was associated with a decreased risk of postoperative opioid dependence.
- Following surgery for degenerative spondylolisthesis, these patients were twice as likely to become opioid independent than they were to become opioid dependent.
Prior to surgery, 15% (1,591) of the patients had an opioid dependency. Between three and 15 months after surgery, however, the percentage of patients with a dependency on opioids was 10% (1,060).
For their analysis, the authors defined indicators of opioid dependence as follows: continued opioid use, more than 10 opioid prescriptions, had counselling regarding psychological and pharmacological treatment options for opioid addiction, or either a diagnosis of opioid dependence disorder or a prescription for treating opioid dependence disorder during the period of one year before or three to 15 months after surgery.
The patient cohort
Sharma and colleagues extracted de-identified data from the MarketScan databases on 10,708 patients who had undergone surgery for degenerative spondylolisthesis. The median age of these patients was 61 years (interquartile range: 54 to 69 years). Of these, 65% were women. In most cases (94%), the surgery was decompression with fusion, and in 76% of patients, surgery involved multiple vertebrae. Many patients (54%) had one or more comorbidities. The majority of patients had commercial health insurance (61% as opposed to 35% with Medicare).