6. Investigations into heterogeneity between subgroups of tests using first rank symptoms to diagnose schizophrenia versus all other diagnoses.
| Schizophrenia versus all other diagnoses | Number of studies | Number of patients |
Summary of sensitivity % (95% CI) |
Summary of specificity % (95% CI) |
Likelihood Ratio Test1 (P‐value) |
|
| Operational criteria used as part of reference standard | DSM‐III | 4 | 1190 | 64.8 (54.3, 74.0) | 64.2 (52.8, 74.2) | 0.002 |
| ICD‐9 | 5 | 2515 | 42.0 (33.5, 51.0) | 89.8 (84.9, 93.2) | ||
| First rank symptoms used as part of reference standard | Unclear | 6 | 1629 | 60.9 (49.3, 71.4) | 85.3 (71.9, 93.0) | 0.3 |
| Yes | 13 | 3316 | 55.3 (47.2, 63.2) | 79.2 (69.2, 86.5) | ||
| All admissions to a psychiatric ward or with specific psychoses | All hospitalised | 8 | 1293 | 59.7 (49.2, 69.4) | 86.7 (77.3, 92.6) | 0.1 |
| Psychosis only | 12 | 3786 | 55.6 (47.3, 63.5) | 77.2 (66.9, 85.0) | ||
| If definition included schizoaffective and/or schizophreniform | Not reported | 9 | 1855 | 45.8 (38.4, 53.3) | 85.1 (75.1, 91.5) | 0.03 |
| Schizophrenic only | 7 | 1619 | 63.2 (54.4, 71.2) | 76.0 (60.6, 86.6) | ||
| Number of first rank symptoms needed for a diagnosis of schizophrenia | At least one | 10 | 3143 | 58.6 (49.5, 67.1) | 76.6 (65.0, 85.3) | 0.5 |
| Not reported | 9 | 1195 | 57.1 (47.1, 66.6) | 84.4 (74.2, 91.0) | ||
1Likelihood ratio test for model with and without covariate DSM: Diagnostic and Statistical Manual of Mental Disorder ICD: International Statistical Classification of Diseases