Table 1

Distribution of 10 264 cases of schizophrenia, 50.7 million person-years at risk and estimates of relative risks for the total study population according to the detailed classification of degree of urbanisation of place of birth

Detailed degree of urbanisation of place of birth1 Cases (n) Person-years Relative risk (95% CI)2
1.Numerals (1)-(5) refer to the 5-level classification of degree of urbanisation: (1) capital; (2) capital suburb; (3) provincial cities with more than 100 000 inhabitants; (4) provincial towns with more than 10 000 inhabitants; (5) rural area.
2.The relative risk was adjusted for age and its interaction with gender, calendar year of diagnosis, ages of the mother and father at the time of child's birth, season of birth and mental illness in a parent or sibling.
3.Built-up areas were defined by cities with more than 2000 inhabitants.
Municipalities in the capital region
Capital (1) 3210 8 926 711 2.30 (2.04-2.60)
Capital suburb (2) 958 4 552 162 1.73 (1.51-1.98)
> 10 000 inhabitants in built-up area (4) 462 2 433 877 1.50 (1.29-1.74)
Other (5) 93 605 615 1.33 (1.06-1.69)
Municipalities where the largest city has more than 10 000 inhabitants
Largest city has more than 100 000 inhabitants (3) 1300 6 429 845 1.58 (1.38-1.79)
Largest city has 40 000-99 999 inhabitants (4) 659 3 691 487 1.39 (1.21-1.60)
Largest city has 20 000-39 999 inhabitants (4) 1102 6 947 291 1.25 (1.10-1.43)
Largest city has 10 000-19 999 inhabitants (4) 688 4 367 539 1.22 (1.06-1.40)
Other municipalities
50-100% of inhabitants in built-up3 area (5) 512 3 450 250 1.14 (0.99-1.32)
33.3-50% of inhabitants in built-up area (5) 685 4 823 608 1.09 (0.95-1.25)
<33.3% of inhabitants in built-up area (5) 313 2 351 639 1.00 (0.85-1.17)
Outside built-up area (reference) (5) 282 2 118 632 1.00