Intraclass correlation (with 95% CI), adjusted for sex, birth year and birth order, and IBD as well as subtypes of the disease
| Neighbourhood (at birth) | |
| Any IBD | 2.1% (1.7% to 2.6%) |
| CD | 3.3% (2.4% to 4.5%) |
| UC | 3.0% (2.3% to 3.8%) |
| IBD-U | 3.7% (2.4% to 5.9%) |
CD, Crohn’s disease; IBD-U, IBD unclassified.