Table 1. Baseline Characteristics of the EI and SC Groupsa.
| Characteristic | EI (n = 617) | SC (n = 617) | χ2 or zb | P Value |
|---|---|---|---|---|
| Age, mean (SD), y | 21.2 (3.4) | 21.3 (3.4) | NA | NA |
| Male sex | 318 (51.5) | 322 (52.2) | NA | NA |
| Diagnosis | ||||
| Schizophrenia and schizoaffective disorder | 484 (78.4) | 486 (78.8) | NA | NA |
| Acute and transient psychotic disorder | 87 (14.1) | 87 (14.1) | NA | NA |
| Psychosis not otherwise specified | 46 (7.5) | 44 (7.1) | NA | NA |
| Educational level, mean (SD), y | 10.9 (2.37) | 10.5 (2.44) | −3.186 | .001 |
| Age at onset, mean (SD), y | 20.46 (3.38) | 20.64 (3.59) | −2.746 | .006 |
| DUP, median, d | 92 | 61 | −2.588 | .01 |
| Baseline positive symptoms | 4.18 (0.72) | 4.59 (0.96) | −7.439 | <.001 |
| Baseline negative symptoms | 2.68 (1.29) | 2.68 (1.31) | −0.025 | .98 |
| Baseline affective symptoms | 2.13 (1.18) | 2.02 (1.21) | −1.936 | .05 |
| Suicide attempts during DUP | 0.13 (0.54) | 0.26 (0.74) | −3.163 | .002 |
| Premorbid occupational functioningc | ||||
| Impaired | 47 (7.6) | 48 (7.8) | 0.00 | >.99 |
| Not impaired | 570 (92.4) | 569 (92.2) | NA | NA |
Abbreviations: DUP, duration of untreated psychosis; EI, early intervention; NA, not applicable; SC, standard care.
Data are presented as number (percentage) of study participants unless otherwise indicated. The EI and SC patients were individually matched based on age (±2 years), sex, and diagnosis; 548 pairs were successfully matched. For unmatched EI patients, diagnosis was matched first and then sex. Two EI patients with psychosis not otherwise specified were matched with SC patients with a diagnosis of schizophrenia.
The z values are derived from the Wilcoxon test for paired samples; the χ2 values are derived from the McNemar test.
Impaired premorbid occupational functioning indicates unemployment or prolonged educational stagnation before the onset of illness.