Opioid Use and Misuse Three Months After Emergency Department Visit for Acute Pain.

BACKGROUND: Studies evaluating long-term prescription opioid use are retrospective and based on filled opioid prescriptions from governmental databases. These studies cannot evaluate if opioids were really consumed and are unable to differentiate if they were used for a new pain or chronic pain or were misused. The aim of this study was to assess opioid use rate and reasons for consuming 3 months after being discharged from the emergency department (ED) with an opioid prescription. METHODS: This is a prospective cohort study conducted in the ED of a tertiary care urban center with a convenience sample of discharged patients ≥ 18 years who consulted for an acute pain condition (≤2 weeks). Three months post-ED visit, participants were interviewed by phone on their past 2-week opioid consumption and their reasons for consuming: a) for pain related to the initial ED visit, b) for a new unrelated pain, or c) for another reason. RESULTS: Of the 524 participants questioned at 3 months (mean ± SD age = 51 ± 16 years, 47% women), 47 patients (9%, 95% confidence interval [CI] = 7%-12%) reported consuming opioids in the previous 2 weeks. Among those, 34 (72%) reported using opioids for their initial pain, nine (19%) for a new unrelated pain and four (9%) for another reason (0.8%, 95% CI = 0.3%-2.0%, of the whole cohort). Patients who used opioids during the 2 weeks after the ED visit were 3.8 (95% CI = 1.2-12.7) times more likely to consume opioids at 3 months. CONCLUSION: Opioid use at the 3-month follow-up in ED patients discharged with an opioid prescription for an acute pain condition is not necessarily associated with opioid misuse; 91% of those patients consumed opioids to treat pain. Of the whole cohort, less than 1% reported using opioids for reasons other than pain. The rate of long-term opioid use reported by prescription-filling database studies should not be viewed as a proxy for incidence of opioid misuse.