Cluster analysis and subgroup characterization among people who made frequent emergency department visits from Apr. 1, 2013, to Mar. 31, 2014 — Alberta
| Characteristic | Subgroup 1 (“Short duration”) | Subgroup 2 (“Older patients”) | Subgroup 3 (“Young mental health”) | Subgroup 4 (“Injury”) |
|---|---|---|---|---|
| Subgroup characteristics (clustering variables) | ||||
| No. of patients | 4301 | 18776 | 12827 | 67722 |
| Age, yr, median (IQR) | 44 (31–58) | 64 (48–78) | 40 (28–55) | 40 (27–58) |
| No. of visits to the emergency department, median (IQR) | 3 (2–4) | 3 (2–5) | 7 (4–11) | 3 (2–4) |
| Charlson Comorbidity Index, median (IQR) | 0 (0–0) | 1 (1–1) | 0 (0–0) | 0 (0–0) |
| No. of different discharge diagnosis chapters, median (IQR) | 2 (2–2) | 4 (3–5) | 5 (5–6) | 3 (2–4) |
| No. of months in the year that patients visited the emergency department, median (IQR) | 1 (1–1) | 4 (3–5) | 7 (6–8) | 3 (2–4) |
| Regularity index, median (IQR) | 1 (0.8–1) | 1 × 10−7 (0.7 × 10−7 to 3.8 × 10−5) | 1.6 × 10−7 (1.2 × 10−7 to 2.6 × 10−7) | 0.9 × 10−7 (0.6 × 10−7 to −8.6 × 10−5) |
| Patient characteristics (NACRS metadata) | ||||
| Gender, n (%) | ||||
| Female | 1868 (43.4) | 9744 (51.9) | 7766 (60.5) | 37888 (55.9) |
| Male | 17241 (50.5) | 35420 (47.2) | 20030 (40.7) | 126667 (43.3) |
| Other | 0 (0.0) | 0 (0.0) | 0 (0.0) | 1 (0.0) |
| Undifferentiated | 0 (0.0) | 0 (0.0) | 1 (0.0) | 1 (0.0) |
| Not available | 0 (0.0) | 0 (0.0) | 0 (0.0) | 1 (0.0) |
| Rural or urban, n (%) | ||||
| Rural | 1428 (33.2) | 6720 (35.8) | 5526 (43.1) | 22378 (33.0) |
| Urban | 2850 (66.3) | 11921 (63.5) | 6846 (53.4) | 44610 (65.9) |
| Emergency department visit characteristics (NACRS metadata) | ||||
| No. of emergency department visits | 499395 | 1587307 | 139770 | 780967 |
| Top 5 ICD-10 emergency department primary diagnoses, n (%) | ||||
| 1 | Drug therapies 12356 (48.0) | Drug therapies 9492 (7.0) | Drug therapies 31466 (15.3) | Drug therapies 38202 (9.9) |
| 2 | Dressings 1574 (6.1) | COPD 4599 (3.4) | Dressings 6016 (2.9) | Dressings 12771 (3.3) |
| 3 | Other medical care 823 (3.2) | Bronchitis 4241 (3.1) | Abdominal pain 5650 (2.7) | UTI 9159 (2.4) |
| 4 | Cellulitis of lower limb 623 (2.4) | CHF 3919 (2.9) | UTI 4044 (2.0) | Abdominal pain 9075 (2.4) |
| 5 | Periapical abscess 372 (1.4) | Asthma 3025 (2.2) | Alcohol intoxication 4329 (2.1) | Orthopedic care 8380 (2.2) |
| Visit disposition, n (%) | ||||
| Discharged | 23892 (92.9) | 102510 (76.0) | 177626 (86.3) | 334800 (87.0) |
| Left against medical advice | 409 (1.6) | 3306 (2.5) | 10731 (5.2) | 14663 (3.8) |
| Admitted | 762 (3.0) | 24873 (18.4) | 14082 (6.8) | 27476 (7.1) |
| Transferred to another facility | 654 (2.5) | 4090 (3.0) | 3376 (1.6) | 7861 (2.0) |
| Died | 2 (0.0) | 119 (0.1) | 37 (0.0) | 53 (0.0) |
| Hospitalization characteristics (DAD metadata) | ||||
| No. of patients with at least 1 admission (%) | 603 (14.0) | 10926 (58.2) | 6209 (48.4) | 18857 (27.8) |
| No. of admissions | 728 | 26281 | 15937 | 29826 |
| Top 5 ICD-10-CA primary diagnosis chapters, n (%) | ||||
| 1 | Digestive 125 (17.2) | Circulatory 6145 (23.4) | Mental and behavioural 3522 (22.1) | Digestive 4581 (15.4) |
| 2 | Injury and poisoning 120 (16.5) | Respiratory 5693 (21.7) | Digestive 2933 (18.4) | Injury and poisoning 4404 (14.8) |
| 3 | Genitourinary 73 (10) | Abnormal clinical findings 2175 (8.3) | Injury and poisoning 1655 (10.4) | Mental and behavioural 3526 (11.8) |
| 4 | Pregnancy 71 (9.8) | Digestive 2033 (7.7) | Abnormal clinical findings 1347 (8.5) | Abnormal clinical findings 2647 (8.9) |
| 5 | Circulatory 57 (7.8) | Endocrine 1558 (5.9) | Respiratory 906 (5.7) | Genitourinary 2405 (8.1) |
| All alcohol-related diagnoses, n (%) | ||||
| No | 726 (99.7) | 26117 (99.4) | 14479 (90.9) | 28939 (97.0) |
| Yes | 2 (0.3) | 164 (0.6) | 1458 (9.1) | 887 (3.0) |
| Mental health hospitalization–related characteristics (HMHDB metadata) | ||||
| No. of patients with at least 1 admission (%) | 58 (1.3) | 1399 (7.5) | 2842 (22.2) | 4522 (6.7) |
| No. of mental health–related admissions | 85 | 2400 | 10 065 | 9439 |
| Diagnosis category among mental health–related admissions, n (%) | ||||
| Mood disorder | 18 (21.2) | 433 (18) | 1629 (16.2) | 2137 (22.6) |
| Schizophrenic and psychotic disorder | 19 (22.4) | 288 (12) | 1350 (13.4) | 1555 (16.5) |
| Substance-related disorder | 20 (23.5) | 536 (22.3) | 4583 (45.5) | 3236 (34.3) |
| Organic disorder | 9 (10.6) | 739 (30.8) | 252 (2.5) | 587 (6.2) |
| Other mental health disorder | 12 (14.1) | 210 (8.8) | 1110 (11.0) | 1144 (12.1) |
| Anxiety disorder | 4 (4.7) | 146 (6.1) | 407 (4.0) | 421 (4.5) |
| Personality disorder | 1 (1.2) | 43 (1.8) | 708 (7.0) | 322 (3.4) |
| Non–mental health disorder | 2 (2.4) | 5 (0.2) | 26 (0.3) | 37 (0.4) |
Note: CHF = congestive heart failure, COPD = chronic obstructive pulmonary disease, DAD = Discharge Abstract Database, HMHDB = Hospital Mental Health Database, ICD-10-CA = International Statistical Classification of Diseases and Related Health Problems, 10th revision, Canadian version, IQR = Interquartile range, NACRS = National Ambulatory Care Reporting System, UTI = urinary tract infection.