Table 1.
Background Characteristics for Schizophrenia Patients and Their Relatives
| Index Patients With Schizophrenia | Children of Patients With Schizophrenia | Siblings of Patients With Schizophrenia | Parents of Patients With Schizophrenia | |
|---|---|---|---|---|
| Number | 31 193 | 13 948 | 44 675 | 15 637 |
| Males/females, % | 59/41 | 52/48 | 51/49 | 42/58 |
| Year of birth, median (IQR)a | 1955 (20)a | 1973 (15) | 1954 (18) | 1941 (11)a |
| Calendar year of first entry, median (IQR) | 1997 (5) | 1997 (4) | 1997 (5) | 1998 (8) |
| Age at first entry, median (IQR) | 44 (19) | 26 (15)/35 (15)b | 44 (18)/54 (18)b | 58 (10)/67 (11)b |
| Person-time of follow-up evaluation (person-years) | 290 227 | 127 824 | 415 513 | 126 447 |
Note: IQR = interquartile range. All subjects were identified in a Swedish nationwide population-based cohort with earliest start of follow-up in 1997.
aSchizophrenia patients without information regarding one or both parents were also included. This was more common for individuals born early in the study period. Median paternal/maternal age can hence not be correctly estimated from this data as parents of these individuals do not contribute to median year of birth among parents.
bAttained age at start/stop follow-up.