Pain is one of the most common complaints in emergency department (ED) and is still often poorly managed. A major prospective multicenter study reported that 74% of patients that had a pain complaint at ED triage are discharged in moderate to severe pain. Accordingly, physicians frequently prescribed analgesic after discharged for these patients, and opioid is given in 29% of ED visits involving pain complaints. However, few studies evaluate pain management after ED discharge: the frequency and length of opioids prescriptions, the opioids quantity taken by the patients, are the patients relieved and satisfied by these pain treatments, what are the adverse effects associated with the use of these medications, and what are the chances of developing addiction?

The primary aim of this study is to determine the required minimal opioids prescription for patients treated for acute pain after being discharge from the ED. Secondary objectives include: 1) monitor the patients' adverse events during opioids treatment; 2) evaluate the patients' level of pain relief associated with their respective opioids treatment; 3) determine the patients' level of addiction following post-ED opioids treatments.

The design of the project is a prospective observational cohort study. A cohort of consecutive ED patients aged 18 or more with an initial pain at triage of 4 or more and discharged from the ED in less than 48 hours with a prescription of opioid will be asked to participate in the study. Patients will be excluded if there is ongoing treatment for a pre-existing chronic pain condition or if they used opioid drugs in the past year. Research nurses will contact the patients by phone at three follow-up time points (1 week, 1 month, and 3 months). Follow-up phone interviews will evaluate pain intensity as well as pain treatment satisfaction (0-10 NRS), monitor adverse events, and investigate possible opioids addiction (SOWS: subjective opioid withdrawal scale). During these interviews, the nurses will also question the patients about their daily opioids usage and if they were relieved from pain.

This study will provide the base for future guidelines regarding the prescription of opioids treatment for specific pathology encountered in ED. It will also give indications on how to adjust the treatments according to adverse events and the level of addiction experienced by patients.

Inclusion Criteria:

• 18 years and older
• Pain level at 4 or greater at triage
• Acute pain (2 weeks or less)
• Opioids prescription at discharge

Exclusion Criteria:

• Language barrier
• Pregnancy
• Treated for chronic pain
• Hospital stay greater than 48 hours

A cohort of consecutive emergency department patients aged 18 or more treated for an acute pain diagnosis present for less than two weeks, with an initial pain at triage of 4 and more on a 0-10 points NRS and discharged with a prescription of opioids.

The study will take place in an emergency department of a tertiary (trauma specialized center) academic urban hospital with an annual census of approximately 60,000 ED visits.