Table 1. Sample Characteristics by Case Status.
| Characteristic | Controls, No. (%) (n = 26 729 [50.0%]) | Cases, No. (%) (n = 26 729 [50.0%]) | χ2 | df | P value | |
|---|---|---|---|---|---|---|
| Psychotic disorder (n = 12 947 [48.4%]) | Nonpsychotic bipolar disorder (n = 13 782 [51.6%]) | |||||
| Sex | ||||||
| Male | 11 356 (42.5) | 7417 (57.3) | 3939 (28.6) | 2251.4 | 1 | <.001 |
| Female | 15 373 (57.5) | 5530 (42.7) | 9843 (71.4) | |||
| Parental migrant status | ||||||
| Swedish born | 22 324 (83.5) | 9724 (75.1) | 11 241 (81.6) | 405.0 | 2 | <.001 |
| Migrant | 4405 (16.5) | 3223 (24.9) | 2541 (18.4) | |||
| Other Europe | 1894 (7.1) | 1313 (10.1) | 1308 (9.5) | |||
| Asia | 134 (0.5) | 68 (0.5) | 22 (0.2) | |||
| North Africa and Middle East | 628 (2.4) | 375 (2.9) | 115 (0.8) | |||
| Sub-Saharan Africa | 93 (0.4) | 130 (1.0) | 12 (0.1) | |||
| Mixed | 1570 (5.9) | 1279 (9.9) | 1043 (7.6) | |||
| Othera | 8.6 (0.3) | 58 (0.5) | 41 (0.3) | |||
| Parental history of SMI | ||||||
| 0 | 25 827 (96.6) | 11 418 (88.2) | 11 952 (86.7) | 1559.9 | 2 | <.001 |
| 1 | 787 (2.9) | 1312 (10.1) | 1573 (11.4) | |||
| 2 | 115 (0.4) | 217 (1.7) | 257 (1.9) | |||
| Parental disposable income at birth | ||||||
| 1 (Lowest quintile) | 4814 (18.0) | 3137 (24.2) | 2967 (21.5) | 286.4 | 8 | <.001 |
| 2 | 5469 (20.5) | 2730 (21.2) | 3013 (21.9) | |||
| 3 | 5534 (20.7) | 2370 (18.3) | 2818 (20.5) | |||
| 4 | 5554 (20.8) | 2423 (18.7) | 2477 (18.0) | |||
| 5 (Highest quintile) | 5358 (20.1) | 2287 (17.7) | 2507 (18.2) | |||
| Deprivation at birth | ||||||
| 1 (Lowest quintile) | 4464 (16.7) | 1894 (14.6) | 2016 (14.6) | 239.2 | 8 | <.001 |
| 2 | 5362 (20.1) | 2291 (17.7) | 2536 (18.4) | |||
| 3 | 5708 (21.4) | 2546 (19.7) | 2813 (20.4) | |||
| 4 | 5581 (20.9) | 2696 (20.8) | 2997 (21.8) | |||
| 5 (Highest quintile) | 5614 (21.0) | 3520 (27.2) | 3420 (24.8) | |||
| Population density at birth | ||||||
| 1 (Lowest quintile) | 2703 (10.1) | 1025 (7.9) | 1357 (9.9) | 311.6 | 8 | <.001 |
| 2 | 3719 (13.9) | 1462 (11.3) | 1806 (13.1) | |||
| 3 | 4940 (18.5) | 2120 (16.4) | 2295 (16.7) | |||
| 4 | 7114 (26.6) | 3259 (25.2) | 3584 (26.0) | |||
| 5 (Highest quintile) | 8253 (30.9) | 5081 (39.2) | 4740 (34.4) | |||
| Moves between birth year and 14th year of follow-up | ||||||
| 0 | 11 761 (44.0) | 4435 (33.6) | 4502 (32.7) | 842.8 | 4 | <.001 |
| 1-4 | 14 141 (52.9) | 7825 (60.4) | 8387 (60.9) | |||
| ≥5 | 827 (3.1) | 777 (6.0) | 893 (6.5) | |||
| Moves between diagnosis year and end of follow-up | ||||||
| 0 | 12 889 (48.2) | 6441 (49.8) | 6530 (47.4) | 39.1 | 4 | <.001 |
| 1-4 | 13 125 (49.1) | 6067 (46.9) | 6879 (49.9) | |||
| ≥5 | 715 (2.7) | 439 (3.4) | 373 (2.7) | |||
| Diagnosis (ICD-10 code) | ||||||
| Schizophrenia (F20) or schizoaffective disorders (F25) | NA | 2942 (22.7) | NA | NA | NA | NA |
| Affective psychosis (F30-33) | NA | 3369 (26.0) | NA | |||
| Bipolar psychosis (F30-31) | NA | 1153 (8.9) | NA | |||
| Depressive psychosis (F32-33) | NA | 2216 (17.1) | NA | |||
| Other nonaffective psychosis (F2X) | NA | 6636 (51.3) | NA | |||
| Bipolar or mania without psychosis | NA | NA | 13 782 (100) | |||
Abbreviations: ICD-10, International Statistical Classification of Diseases and Related Health Problems, Tenth Revision; NA, not applicable; SMI, severe mental illness.
a
Other includes any other part of the world not included in the aforementioned areas, such as Australasia and the Americas.