Baseline characteristics
| Overall | Patients with opioids | Patients without opioids | P value | |
| No of patients | 26 224, 100% | 1906, 7.3% | 24 318, 92.7% | |
| Age (years) | 63 (IQR 44–78) | 76 (IQR 59–85) | 62 (IQR 42–77) | <0.0001 |
| Gender | ||||
| Female | 12 998, 49.6% | 1105, 58% | 11 893, 48.9% | <0.0001 |
| Male | 13 226, 50.4% | 801, 42.0% | 12 425, 51.1% | |
| Hospitalisation rate | 13 583, 51.8% | 1492, 78.3% | 12 091, 49.7% | <0.0001 |
| Length of stay (days) | 1 (IQR 1–4) | 5 (IQR 1–8) | 1 (IQR 1–4) | <0.0001 |
| Readmission within 72 hours | 94, 0.4% | 15, 0.8% | 79, 0.3% | 0.004 |
| Rehospitalisation within 30 days | 478 to 1.8% | 119, 6.2% | 359, 1.5% | <0.0001 |
| Mortality | 510, 1.9% (95% CI 1.8–2.1) | 121, 6.3% (95% CI 5.3–7.4) | 389, 1.6% (95% CI 1.4–1.8) | <0.0001 |
| Scheduled opioids | 1906, 7.3% (95% CI 7.0–7.6) | |||
| Use of non-opioid analgesics | 5154, 19.7% | 954, 50.1% | 4200, 17.3% | <0.0001 |
| Paracetamol | 2794, 10.7% | 569, 29.9% | 2225, 9.1% | <0.0001 |
| Metamizole | 1664, 6.3% | 409, 21.5% | 1255, 5.2% | <0.0001 |
| NSAIDs | 2797, 10.7% | 372, 19.5% | 2425, 10% | <0.0001 |
| Indications for opioids | ||||
| Malignancy | 374, 19.6% | |||
| Musculoskeletal | 1145, 60.1% | |||
| Other | 290, 15.2% | |||
| Unknown | 340, 17.8% | |||
| Reasons for presentation to the ED | ||||
| Related to opioid therapy | 154, 0.6% (95% CI 0.5–0.7) | 154, 8.1% (95% CI 6.9–9.3) | 0, 0% | |
| Fall | 1450, 5.5% (95% CI 5.3–5.8) | 138, 7.2% (95% CI 6.1–8.4) | 1312, 5.4% (95% CI 5.1–5.7) | 0.001 |
| Constipation | 704, 2.7% (95% CI 2.5–2.9) | 98, 5.1% (95% CI 4.2–6.1) | 606, 2.5% (95% CI 2.3–2.7) | <0.0001 |
| Delirium | 718, 2.7% (95% CI 2.5–2.9) | 106, 5.6% (95% CI 4.5 –6.6) | 612, 2.5% (95% CI 2.3 –2.7) | <0.0001 |
| Vertigo | 751, 2.9% (95% CI 2.7 –3.1) | 58, 3.0% (95% CI 2.3–3.8) | 693, 2.8% (95% CI 2.6–3.1) | 0.62 |
| eGFR (mL/min) | 85 (IQR 63–107) | 72 (IQR 47–93) | 86 (IQR 65–107) | <0.0001 |
ED, emergency department; eGFR, estimated glomerular filtration rate (CKD-EPI formula); NSAIDs, non-steroidal anti-inflammatory drugs.