Trajectories of Opioid Coverage After Long-Term Opioid Therapy Initiation Among a National Cohort of US Veterans

Abstract

Purpose The objective of this study was to identify the trajectories that patients take after initiating long-term opioid therapy (LTOT). Materials and Methods Using a retrospective cohort design, veterans with chronic non-cancer pain (CNCP) initiating LTOT were identified. Group-based trajectory models were used to identify opioid therapy trajectories based on days of opioid supply (primary outcome) and average daily morphine milligram equivalent dose (AMME; secondary outcome) in each 180-day period following initiation of LTOT. Results A total of 438,398 veterans with CNCP initiated LTOT. Nine trajectories were identified: 33.7% with persistent, high days covered, 17.7% with persistent, moderate days covered, 16.6% with slow, persistent days-covered reduction, 2.4% with days-covered reduction followed by increase, 4.6% with delayed days-covered reduction, 4.1% with rapid days-covered reduction, 10.9% with moderate-paced discontinuation, 3.4% with delayed discontinuation, and 6.5% with rapid discontinuation. Patients following discontinuation trajectories were more likely to be younger, persons of color, use more supportive services (eg, physical therapy), and received less opioid days’ supply and lower doses prior to initiating LTOT as compared to patients following persistent opioid days-covered trajectories. AMME trajectories were similar to days-covered trajectories. Conclusion Among persons initiating LTOT, nine opioid trajectories emerged which can be broadly characterized into three main trajectory groups: persistent opioid therapy (2 trajectories), reductions in opioid therapy (4 trajectories), and discontinuation (3 trajectories). A majority of patients (51.4%) maintained persistent opioid therapy. Further research is needed to assess the risks of opioid-related adverse outcomes among the identified trajectories.

Opioid Dose Trajectories and Associations With Mortality, Opioid Use Disorder, Continued Opioid Therapy, and Health Plan Disenrollment

“…GBTM has been applied to data across many Department of Veterans Affairs clinics, but has not been extensively applied to multisite studies from different types of health systems; thus, we explored site interactions in all models. Low numbers from 2 sites precluded robust site-specific estimates and larger sample size is needed to definitively test the association between decreasing and overdose, given findings reported by Agnoli and colleagues .…”

“…For example, a physician may temporarily increase the dose to treat acute pain, or abruptly discontinue opioids if there is evidence of nonprescribed drug use. This study’s objective was to identify subpopulations of patients with distinct, clinically meaningful trajectory patterns over a 1-year period using group-based trajectory modeling (GBTM) . We also aimed to compare baseline characteristics across trajectories and outcomes occurring after the trajectory including 1-year all-cause mortality, incident OUD, continued opioid therapy, disenrollment from the health plan, and overdose.…”

Association between opioid therapy trajectories and potential opioid‐related adverse health events

“…Figure 1 shows the study timeframe. Additional details on the development of veteran trajectory groups can be found in a previous manuscript 32 . To test for differences between veteran trajectory group means, we used t ‐tests for continuous variables and chi‐square tests for categorical variables.…”