Table 2.
Characteristics of clozapine and other antipsychotic groups in patients with treatment‐resistant schizophrenia
| Clozapine (N = 1025) | Non‐clozapine (N = 1812) | P a | |
|---|---|---|---|
| Sociodemographic variables | |||
| Age, mean (standard deviation) | 39.2 (10.7) | 38.4 (11.8) | |
| <35 years | 385 (37.6) | 791 (43.7) | <0.001 |
| 35 to <55 years | 561 (54.7) | 845 (46.6) | |
| 55 years or older | 79 (7.7) | 176 (9.7) | |
| Gender | 0.002 | ||
| Women | 679 (66.2) | 1095 (60.4) | |
| Men | 346 (33.8) | 717 (39.6) | |
| Ethnicity | <0.001 | ||
| White | 456 (44.5) | 547 (30.2) | |
| Black | 422 (41.2) | 1012 (55.8) | |
| Asian | 61 (6.0) | 97 (5.4) | |
| Mixed | 84 (8.2) | 153 (8.4) | |
| Other or not stated | 2 (0.2) | 3 (0.2) | |
| Marital status | 0.084 | ||
| Single | 863 (84.2) | 1464 (80.8) | |
| Married or cohabiting | 82 (8.0) | 157 (8.7) | |
| Divorced or separated | 74 (7.2) | 180 (9.9) | |
| Not known or not disclosed | 6 (0.6) | 11 (0.6) | |
| Deprivation level in area of residence | <0.001 | ||
| Quartile 1 (the highest) | 212 (20.7) | 378 (20.9) | |
| Quartile 2 | 213 (20.8) | 379 (20.9) | |
| Quartile 3 | 171 (16.7) | 417 (23.0) | |
| Quartile 4 | 199 (19.4) | 402 (22.2) | |
| Homeless | 22 (2.1) | 79 (4.4) | |
| Unknown | 208 (20.3) | 157 (8.7) | |
| Substance use disorders | |||
| History of alcohol‐related disorders | 0.059 | ||
| No | 979 (95.5) | 1700 (93.8) | |
| Yes | 46 (4.5) | 112 (6.2) | |
| History of opioid‐related disorders | 0.005 | ||
| No | 1014 (98.9) | 1764 (97.4) | |
| Yes | 11 (1.1) | 48 (2.6) | |
| Clinical monitoring | |||
| Face‐to‐face contact days (% of follow‐up time) | <0.001 | ||
| Quartile 1 | 183 (17.9) | 526 (29.0) | |
| Quartile 2 | 183 (17.9) | 528 (29.1) | |
| Quartile 3 | 263 (25.7) | 445 (24.6) | |
| Quartile 4 (the highest) | 396 (38.6) | 313 (17.3) | |
| Mental health symptom severity | |||
| Agitated behaviour | <0.001 | ||
| No problem | 567 (55.3) | 571 (31.5) | |
| Minor problem | 220 (21.5) | 426 (23.5) | |
| Mild problem | 126 (12.3) | 382 (21.1) | |
| Moderate problem | 56 (5.5) | 256 (14.1) | |
| Severe problem | 34 (3.3) | 154 (8.5) | |
| Missing | 22 (2.1) | 23 (1.3) | |
| Hallucinations and delusions | <0.001 | ||
| No problem | 218 (21.3) | 293 (16.2) | |
| Minor problem | 153 (14.9) | 225 (12.4) | |
| Mild problem | 291 (28.4) | 427 (23.6) | |
| Moderate problem | 227 (22.1) | 549 (30.3) | |
| Severe problem | 113 (11.0) | 294 (16.2) | |
| Missing | 23 (2.2) | 24 (1.3) | |
| Depressed mood | 0.002 | ||
| No problem | 495 (48.3) | 835 (46.1) | |
| Minor problem | 309 (30.1) | 513 (28.3) | |
| Mild problem | 159 (15.5) | 307 (16.9) | |
| Moderate problem | 31 (3.0) | 108 (6.0) | |
| Severe problem | 9 (0.9) | 26 (1.4) | |
| Missing | 22 (2.1) | 23 (1.3) | |
| Additional mental and physical health problems | |||
| Non‐accidental self‐injury | 0.096 | ||
| No problem | 901 (87.9) | 1549 (85.5) | |
| Minor problem | 52 (5.1) | 112 (6.2) | |
| Mild problem | 27 (2.6) | 67 (3.7) | |
| Moderate problem | 15 (1.5) | 39 (2.2) | |
| Severe problem | 8 (0.8) | 21 (1.2) | |
| Missing | 22 (2.1) | 24 (1.3) | |
| Problem‐drinking or drug taking | <0.001 | ||
| No problem | 752 (73.4) | 1178 (65.0) | |
| Minor problem | 105 (10.2) | 181 (10.0) | |
| Mild problem | 80 (7.8) | 205 (11.3) | |
| Moderate problem | 57 (5.6) | 159 (8.8) | |
| Severe problem | 6 (0.6) | 63 (3.5) | |
| Missing | 25 (2.4) | 26 (1.4) | |
| Physical illness or disability problems | <0.001 | ||
| No problem | 596 (58.1) | 1228 (67.8) | |
| Minor problem | 196 (19.1) | 263 (14.5) | |
| Mild problem | 146 (14.2) | 195 (10.8) | |
| Moderate problem | 55 (5.4) | 74 (4.1) | |
| Severe problem | 10 (1.0) | 30 (1.7) | |
| Missing | 22 (2.1) | 22 (1.2) | |
| Functional status | |||
| Activities of daily living (ADLs) | 0.219 | ||
| No problem | 402 (39.2) | 709 (39.1) | |
| Minor problem | 269 (26.2) | 445 (24.6) | |
| Mild problem | 210 (20.5) | 390 (21.5) | |
| Moderate problem | 103 (10.0) | 196 (10.8) | |
| Severe problem | 18 (1.8) | 48 (2.6) | |
| Missing | 23 (2.2) | 24 (1.3) | |
| Standard of living conditions | <0.001 | ||
| No problem | 637 (62.1) | 875 (48.3) | |
| Minor problem | 186 (18.1) | 342 (18.9) | |
| Mild problem | 88 (8.6) | 263 (14.5) | |
| Moderate problem | 48 (4.7) | 133 (7.3) | |
| Severe problem | 28 (2.7) | 147 (8.1) | |
| Missing | 38 (3.7) | 52 (2.9) | |
| Occupational and recreational activities | <0.001 | ||
| No problem | 433 (42.2) | 627 (34.6) | |
| Minor problem | 269 (26.2) | 422 (23.3) | |
| Mild problem | 195 (19.0) | 465 (25.7) | |
| Moderate problem | 68 (6.6) | 169 (9.3) | |
| Severe problem | 25 (2.4) | 77 (4.2) | |
| Missing | 35 (3.4) | 52 (2.9) | |
| Social relationships | <0.001 | ||
| No problem | 358 (34.9) | 516 (28.5) | |
| Minor problem | 282 (27.5) | 431 (23.8) | |
| Mild problem | 234 (22.8) | 520 (28.7) | |
| Moderate problem | 97 (9.5) | 234 (12.9) | |
| Severe problem | 32 (3.1) | 85 (4.7) | |
| Missing | 22 (2.1) | 26 (1.4) | |
a
Pvalues represent the significance of difference between the clozapine and non‐clozapine groups, as assessed by chi‐squared tests for categorical variables and the student independent t test for continuous variables.