Characteristics associated with overdose-related and non-overdose-related visits to emergency departments in British Columbia, 2015–2016
| Characteristic | Patient group and reason for visit; no. (%) of patients* | |||||
|---|---|---|---|---|---|---|
| All patients | Discharged | Left against medical advice | ||||
| Overdose n = 3593 | Non-overdose n = 216 453 | Overdose n = 3133 | Non-overdose n = 187 932 | Overdose n = 150 | Non-overdose n = 7960 | |
| Index visits to ED | ||||||
| Health authority | ||||||
| Interior Health | 73 (2.0) | 23 432 (10.8) | 66 (2.1) | 20 028 (10.7) | 2 (1.3) | 765 (9.6) |
| Fraser Health | 1900 (52.9) | 93 487 (43.2) | 1652 (52.7) | 81 882 (43.6) | 42 (28.0) | 3694 (46.4) |
| Vancouver Coastal Health | 1407 (39.2) | 51 274 (23.7) | 1234 (39.4) | 44 539 (23.7) | 96 (64.0) | 1903 (23.9) |
| Island Health | 67 (1.9) | 38 952 (18.0) | 60 (1.9) | 33 638 (17.9) | 1 (0.7) | 1200 (15.1) |
| Northern Health | 137 (3.8) | 8578 (4.0) | 113 (3.6) | 7208 (3.8) | 8 (5.3) | 371 (4.7) |
| Unknown | 9 (0.3) | 730 (0.3) | 8 (0.3) | 637 (0.3) | 1 (0.7) | 27 (0.3) |
| Arrival by ambulance | 2966 (82.5) | 33 062 (15.3) | 2585 (82.5) | 23 525 (12.5) | 139 (92.7) | 1261 (15.8) |
| Canadian Triage and Acuity Scale | ||||||
| 1 (resuscitation) | 128 (3.6) | 1429 (0.7) | 73 (2.3) | 425 (0.2) | 5 (3.3) | 7 (0.1) |
| 2 (emergent) | 1096 (30.5) | 31 827 (14.7) | 888 (28.3) | 23 023 (12.3) | 35 (23.3) | 426 (5.4) |
| 3 (urgent) | 2147 (59.8) | 100 094 (46.2) | 1968 (62.8) | 86 752 (46.2) | 103 (68.7) | 3393 (42.6) |
| 4 (less urgent) | 189 (5.3) | 73 596 (34.0) | 174 (5.6) | 69 851 (37.2) | 6 (4.0) | 2679 (33.7) |
| 5 (nonurgent) | 19 (0.5) | 5415 (2.5) | 19 (0.6) | 4997 (2.7) | 0 (0.0) | 353 (4.4) |
| Unknown | 14 (0.4) | 4092 (1.9) | 11 (0.4) | 2884 (1.5) | 1 (0.7) | 1102 (13.8) |
| Visit length of stay, h, median (IQR) | 3.5 (2.2–5.9) | 2.8 (1.7–4.5) | 3.5 (2.2–5.8) | 2.8 (1.7–4.3) | 3.5 (2.2–5.8) | 2.8 (1.7–4.3) |
| Disposition after index visit | ||||||
| Discharged | 3133 (87.2) | 187 932 (86.8) | – | – | – | – |
| Left against medical advice | 150 (4.2) | 7960 (3.7) | – | – | – | – |
| Admitted or transferred | 310 (8.6) | 20 561 (9.5) | – | – | – | – |
| Patients | ||||||
| Sex, female | 1098 (30.6) | 108 524 (50.1) | 939 (30.0) | 95 837 (51.0) | 33 (22.0) | 3724 (46.8) |
| Age, yr, median (IQR) | 35.0 (27.0–46.0) | 41.0 (28.0–56.0) | 35.0 (27.0–46.0) | 42.0 (28.0–56.0) | 35.0 (27.0–46.0) | 42.0 (28.0–56.0) |
| Age group, yr | ||||||
| 14–35 | 1836 (51.1) | 83 451 (38.6) | 1618 (51.6) | 75 016 (39.9) | 74 (49.3) | 3815 (47.9) |
| 36–55 | 1458 (40.6) | 72 846 (33.7) | 1268 (40.5) | 64 063 (34.1) | 63 (42.0) | 2732 (34.3) |
| 56–74 | 299 (8.3) | 60 156 (27.8) | 247 (7.9) | 48 853 (26.0) | 13 (8.7) | 1413 (17.8) |
| Material deprivation quintile† | ||||||
| 1 (most deprived) | 391 (16.6) | 37 873 (19.6) | 331 (16.3) | 33 318 (19.7) | 21 (25.6) | 1297 (18.7) |
| 2 | 289 (12.3) | 37 265 (19.3) | 238 (11.7) | 32 714 (19.4) | 11 (13.4) | 1263 (18.3) |
| 3 | 347 (14.7) | 36 920 (19.1) | 301 (14.8) | 32 212 (19.1) | 12 (14.6) | 1265 (18.3) |
| 4 | 445 (18.9) | 38 403 (19.9) | 392 (19.3) | 33 381 (19.8) | 12 (14.6) | 1375 (19.9) |
| 5 (least deprived) | 883 (37.5) | 42 981 (22.2) | 771 (37.9) | 37 144 (22.0) | 26 (31.7) | 1719 (24.8) |
| Elixhauser index with mental health | ||||||
| 0 | 2606 (72.5) | 197 785 (91.4) | 2379 (75.9) | 179 940 (95.7) | 128 (85.3) | 7586 (95.3) |
| 1 | 451 (12.6) | 10 313 (4.8) | 339 (10.8) | 4920 (2.6) | 10 (6.7) | 234 (2.9) |
| ≥ 2 | 536 (14.9) | 8355 (3.9) | 415 (13.2) | 3072 (1.6) | 12 (8.0) | 140 (1.8) |
| Elixhauser index without mental health | ||||||
| 0 | 3287 (91.5) | 201 901 (93.3) | 2909 (92.9) | 181 496 (96.6) | 144 (96.0) | 7748 (97.3) |
| 1 | 187 (5.2) | 8478 (3.9) | 145 (4.6) | 4251 (2.3) | 2 (1.3) | 145 (1.8) |
| ≥ 2 | 119 (3.3) | 6074 (2.8) | 79 (2.5) | 2185 (1.2) | 4 (2.7) | 67 (0.8) |
| Psychiatric comorbidities | ||||||
| Anxiety | 561 (15.6) | 11 032 (5.1) | 478 (15.3) | 9035 (4.8) | 10 (6.7) | 501 (6.3) |
| Depression | 611 (17.0) | 13 113 (6.1) | 499 (15.9) | 10 379 (5.5) | 18 (12.0) | 590 (7.4) |
| Schizophrenia | 364 (10.1) | 2928 (1.4) | 319 (10.2) | 1658 (0.9) | 12 (8.0) | 135 (1.7) |
| Personality disorders | 195 (5.4) | 992 (0.5) | 161 (5.1) | 582 (0.3) | 3 (2.0) | 45 (0.6) |
| ≥ 1 prescription medication in 365 d before index visit | ||||||
| Opioids for analgesia | 1232 (34.3) | 47 502 (21.9) | 1048 (33.5) | 40 325 (21.5) | 54 (36.0) | 1666 (20.9) |
| Opioid agonist therapy | 1375 (38.3) | 3985 (1.8) | 1215 (38.8) | 2997 (1.6) | 73 (48.7) | 411 (5.2) |
| Benzodiazepines and z-drugs‡ | 1094 (30.4) | 32 867 (15.2) | 934 (29.8) | 26 845 (14.3) | 31 (20.7) | 1280 (16.1) |
| Antidepressant and antipsychotic medications | 1976 (55.0) | 44 193 (20.4) | 1702 (54.3) | 35 988 (19.1) | 74 (49.3) | 1920 (24.1) |
| Incarceration in 365 d before index visit | 788 (21.9) | 2422 (1.1) | 708 (22.6) | 1887 (1.0) | 33 (22.0) | 230 (2.9) |
| Health care encounters in 365 d before index visit, median (IQR) | ||||||
| Hospitalization | 0.0 (0.0–1.0) | 0.0 (0.0–0.0) | 0.0 (0.0–1.0) | 0.0 (0.0–0.0) | 0.0 (0.0–1.0) | 0.0 (0.0–0.0) |
| Ambulance | 1.0 (0.0–1.0) | 0.0 (0.0–0.0) | 1.0 (0.0–1.0) | 0.0 (0.0–0.0) | 1.0 (0.0–1.0) | 0.0 (0.0–0.0) |
| Physician visits§ | 15.0 (5.0–39.0) | 8.0 (3.0–15.0) | 14.0 (5.0–38.0) | 7.0 (3.0–14.0) | 14.0 (5.0–38.0) | 7.0 (3.0–14.0) |
| No. of physicians§ | 10.0 (5.0–18.0) | 7.0 (3.0–11.0) | 10.0 (4.0–18.0) | 6.0 (3.0–11.0) | 10.0 (4.0–18.0) | 6.0 (3.0–11.0) |
| ED visits | 2.0 (0.0–5.0) | 0.0 (0.0–0.0) | 2.0 (0.0–5.0) | 0.0 (0.0–0.0) | 2.0 (0.0–5.0) | 0.0 (0.0–0.0) |
Note: ED = emergency department, IQR = interquartile range.
↵* Except where indicated otherwise.
↵† Data for material deprivation were missing for the following numbers of patients: 1238 of all patients with an overdose-related visit, 23 011 of all patients with a non-overdose-related visit, 1100 of patients who were discharged after an overdose-related visit, 19 163 of patients who were discharged after a non-overdose-related visit, 68 of patients who left against medical advice after an overdose-related visit and 1041 of patients who left against medical advice after a non-overdose-related visit.
↵‡ For example, zolpidem and zopiclone.
↵§ Community or outpatient.