Systemic Opioid Reduction and Discontinuation Following Implantation of Intrathecal Drug-Delivery Systems for Chronic Pain: A Retrospective Cohort Analysis.

objectiveThe study evaluated systemic opioid utilization before and after initiation of intrathecal drug therapy in patients with chronic, noncancer pain, as well as the effect of opioid elimination on payer costs.

methodsThis was a retrospective cohort analysis of administrative claims data (2011-2016), evaluating patients using systemic opioids for chronic, noncancer pain, newly implanted with an intrathecal drug-delivery system. Patients were excluded for spasticity, cancer, and device explant. The primary outcome was reduction or discontinuation of systemic morphine milligram equivalents during a 395-day follow-up period. The secondary outcome was total commercial insurer payments.

resultsOf 9223 total patients, 631 met selection criteria. From baseline to 395-day follow-up, average daily morphine milligram equivalents decreased in 81.5% of patients, and 43.3% discontinued systemic opioid therapy entirely. Among patients who continued systemic opioids, average daily morphine milligram equivalents decreased in 74.9% of patients. Logistic regression found that morphine milligram equivalents of <50 mg/day prior to initiation of intrathecal drug delivery was associated with two times the odds of discontinuation vs. ≥90 mg/day (odds ratio = 2.08, 95% confidence interval 1.42-3.02, p = 0.001). Mean annual payer costs were reduced 29% for patients who discontinued vs. continued systemic opioids (-$11,115 per patient).

conclusionsA meaningful proportion of patients discontinue or decrease systemic opioid use following initiation of intrathecal drug delivery. Standard of care should include opioid dose tapering prior to intrathecal drug delivery to maximize the probability of systemic opioid discontinuation.