| Characteristic | Initiator; no. (%) of patients* | Standardized difference† | |
|---|---|---|---|
| Emergency physician n = 34 713 | Family physician n = 45 952 | ||
| Demographic | |||
| Age, mean ± SD; yr | 41.32 ± 14.0 | 46.05 ± 12.8 | 0.40 |
| Female sex | 20 305 (58.5) | 28 178 (61.3) | 0.06 |
| Income quintile | |||
| 1 | 14 844 (42.8) | 19 822 (43.1) | 0.01 |
| 2 | 7742 (22.3) | 10 291 (22.4) | 0.0 |
| 3 | 5262 (15.2) | 7092 (15.4) | 0.01 |
| 4 | 4073 (11.7) | 5219 (11.4) | 0.01 |
| 5 | 2629 (7.6) | 3331 (7.2) | 0.01 |
| Missing | 163 (0.5) | 197 (0.4) | 0.01 |
| Rural location of residence | 5074 (14.6) | 4312 (9.4) | 0.20 |
| Comorbidities | |||
| Hospital visit for other drug toxicity in prior year | 641 (1.8) | 513 (1.1) | 0.06 |
| Intentional self-harm in prior year | 411 (1.2) | 333 (0.7) | 0.05 |
| Hospital visit for alcohol abuse in prior year | 1553 (4.5) | 1378 (3.0) | 0.08 |
| Osteoarthritis | 5954 (17.2) | 12 387 (27.0) | 0.20 |
| Rheumatoid arthritis | 488 (1.4) | 860 (1.9) | 0.04 |
| Past injury | 6129 (17.6) | 4927 (10.7) | 0.20 |
| HIV infection | 393 (1.1) | 502 (1.1) | 0.0 |
| Diabetes | 6568 (18.9) | 11 505 (25.0) | 0.20 |
| Crohn's disease/colitis | 505 (1.4) | 544 (1.2) | 0.02 |
| Mental health disorders | |||
| Affective disorder | 4162 (12.0) | 4192 (9.1) | 0.09 |
| Anxiety or sleep disorder | 15 339 (44.2) | 20 306 (44.2) | 0.0 |
| Psychosis, agitation or related disorder | 3893 (11.2) | 3755 (8.2) | 0.10 |
| All other mental health disorders | 11 698 (33.7) | 14 020 (30.5) | 0.07 |
| Any mental health disorder | 19 780 (57.0) | 26 056 (56.7) | 0.01 |
| Use of health care services in prior year | |||
| No. of emergency department visits, mean ± SD | 1.86 ± 3.8 | 0.90 ± 2.1 | 0.30 |
| No. of physician visits, mean ± SD | 8.80 ± 8.3 | 11.42 ± 9.8 | 0.30 |
| Inpatient hospital stay | 3780 (10.9) | 4069 (8.8) | 0.07 |
| Medication use in prior 180 d | |||
| SSRI antidepressant | 6647 (19.1) | 8393 (18.3) | 0.02 |
| Other antidepressant | 7149 (20.6) | 10 235 (22.3) | 0.04 |
| Antipsychotic | 5515 (15.9) | 6260 (13.6) | 0.06 |
| Benzodiazepine | 6745 (19.4) | 10 145 (22.1) | 0.07 |
| Other psychotropic drugs and central nervous system depressants | 1031 (3.0) | 996 (2.2) | 0.05 |
| Drugs for neuropathic pain | 379 (1.1) | 665 (1.4) | 0.03 |
| Hydrocodone (cough suppressant) | 433 (1.2) | 1109 (2.4) | 0.09 |
Note: SD = standard deviation, SSRI = selective serotonin reuptake inhibitor.
*Except where noted otherwise.
†Imbalance defined as absolute value greater than 0.10 (small effect size).