Table 1.
Register-based characteristics of individuals with treatment-resistant schizophrenia and schizophrenia without treatment-resistance in Sweden from the population-based analyses (n = 24,706) using two definitions of treatment-resistance
| Definition 1: clozapine-SCZ |
Definition 2: clozapine or polypharmacy-SCZ |
|||
|---|---|---|---|---|
| Variable | Clozapine | No clozapine | Clozapine or polypharmacy | Neither clozapine nor polypharmacy |
|
| ||||
| N | 4813 | 19,893 | 13,779 | 10,927 |
| Male sex | 2996 (62.2%) | 11,178 (56.2%) | 8000 (58.1%) | 6174 (56.5%) |
| Age at 1 July, 2005 | 42.8 years (34.2, 51.5) | 47.5 years (38.1, 55.6) | 44.7 years (35.6, 53.3) | 48.8 years (39.6, 56.5) |
| Psychiatric treatment contacts | ||||
| Inpatient | 1 (0, 5) | 1 (0, 3) | 2 (0, 5) | 0 (0, 2) |
| Outpatient | 10 (4, 21) | 9 (4, 18) | 12 (5, 23) | 7 (2, 13) |
| Comorbid psychiatric diagnoses | ||||
| Major depressive disorder | 844 (17.5%) | 4372 (21.9%) | 2976 (21.2%) | 2240 (20.4%) |
| Suicide attempt | 678 (14.1%) | 2329 (11.7%) | 2082 (15.1%) | 925 (8.5%) |
| Substance use disorder | 654 (13.6%) | 3396 (17.0%) | 2395 (17.4%) | 1655 (15.1%) |
| Antipsychotic usage (duration in weeks)a | ||||
| Adequate antipsychotic dose | 14.9 (52.8) | 20.5 (71.5) | 26.0 (76.2) | 11.2 (55.5) |
| Clozapine | 316.9 (175.4) | 0 | 110.8 (183.3) | 0 |
| Polypharmacy | 143.9 (158.5) | 70.9 (124.9) | 151.8 (150.9) | 1.28 (2.8)b |
| Antipsychotic usage (different medications) | ||||
| Oral antipsychotics | 2 (1, 4) | 2 (1, 3) | 3 (2, 4) | 1 (0, 2) |
| Injectable antipsychotics | 0 (0,1) | 0 (0,1) | 0 (0,1) | 0 (0,1) |
| Year 9 grade at age 16 years, Z-scorea | −0.45 (1.2) | −0.42 (1.2) | −0.46 (1.2) | −0.37 (1.2) |
| Premorbid IQ in males at age 18 years, Z-scorea | −0.58 (1.1) | −0.54 (1.0) | −0.58 (1.1) | −0.51 (1.1) |
| Educational attainment years, Z-scorea | −0.55 (0.8) | −0.38 (0.9) | −0.50 (0.8) | −0.31 (0.9) |
| Schizophrenia family history score, Z-scorea | 1.1 (3.3) | 0.81 (2.9) | 0.95 (3.2) | 0.74 (2.8) |
Data are n (%), median (interquartile range)
a
Mean (SD)
b
Individuals with polypharmacy 90 < days and no clozapine