Study design:
Retrospective cohort OBJECTIVE.: To identify gaps in opioid prescription immediately prior to spinal fusion and to study the effect of such simulated “opioid weaning/elimination” on risk of long-term post-operative opioid use.
Summary of background data:
Numerous studies have described pre-operative opioid duration and dose thresholds associated with sustained post-operative opioid use. However, the benefit and duration of pre-operative opioid weaning before spinal fusion has not been elaborated.
Methods:
Humana commercial insurance data (2007-Q1 2017) was used to study primary cervical and lumbar/thoracolumbar fusions. More than 5,000 total morphine equivalents (TME) in the year before spinal fusion was classified as chronic pre-operative opioid use. Based on time between last opioid prescription (<14-days' supply) and spinal fusion, chronic opioid users were divided as; no gap (NG), >2-months gap (2G) and >3-months gap (3G). Primary outcome measure was long-term post-operative opioid use (>5,000 TME between 3-12-months post-operatively). The effect of “opioid gap” on risk of long-term post-operative opioid use was studied using multiple-variable logistic regression analyses.
Results:
17,643 patients were included, of which 3,590 (20.3%) had chronic pre-operative opioid use. Of these patients, 41 (1.1%) were in the 3G group and 106 (3.0%) were in the 2G group. In the 2G group, 53.8% patients ceased to have long-term post-operative use as compared to 27.8% in NG group. This association was significant on logistic regression analysis (OR 0.30, 95% CI: 0.20-0.46, p < 0.001).
Conclusions:
Chronic opioid users whose last opioid prescription was >2-months prior to spinal fusion and less than 14-days’ supply had significantly lower risk of long-term post-operative opioid use. We have simulated “opioid weaning” in chronic opioid users undergoing major spinal fusion and our analysis provides an initial reference point for current clinical practice and future clinical studies.
Level of evidence:
3.