Associations between initial opioid exposure and the likelihood for long-term use

Abstract

ObjectivesThis study examined the association between initial opioid exposure and subsequent long-term use in 2 national Veterans Administration (VA) cohorts from 2011 and 2016, a period during which opioid prescribing declined. DesignTwo methodologies were used to determine the relationship between initial exposure and subsequent long-term use. Setting and participantsIncident opioid users during 2016 were identified using national VA administrative data. Outcome measuresRelationships between days’ supply, daily dose, and number of fills within the first 30 days and subsequent long-term opioid use were also examined. All analyses were repeated for an identically derived cohort during 2011. ResultsIn 2016, 6.2% (method 1: Deyo replication) or 16.8% (method 2: Shah replication) of incident opioid users progressed to long-term opioid use. In 2011, 14.3% (method 1) or 29.2% (method 2) of incident users progressed to long-term use. Cumulative days’ supply emerged as the strongest predictor in a multivariable model of long-term opioid use, which occurred in 1.5% of patients dispensed 7 days’ supply or less and in 27.7% of patients dispensed greater than 30 days’ supply. Results were similar in the 2011 cohort. Although the relationship between days’ supply of incident opioid exposure and long-term opioid use remained consistent over time (in both 2011 and 2016), the overall rate of becoming a long-term opioid user decreased over time across levels of initial exposure. ConclusionThe findings confirm existing literature demonstrating a strong relationship between initial opioid exposure and future likelihood for long-term use. This valuable prognostic information could potentially be leveraged for intervention, including pharmacist-based approaches to prevent progression to long-term opioid use when it is unintended or clinically inappropriate.