Crude rate ratio and rate difference for the association between regional population density and death in motor vehicle crashes in Sweden 1998–2004
| Regional population density | |||
| Low | Medium | High | |
| Prehospital deaths | 476 | 2,193 | 438 |
| PY at risk | 6 460 531 | 43 272 278 | 12 797 190 |
| Mortality rate per 100 000 PY | 7.4 | 5.1 | 3.4 |
| Crude rate ratio (95% CI) | 2.2 (1.9 to 2.5) | 1.5 (1.3 to 1.6) | Ref |
| Crude rate difference per 100 000 PY (95% CI) | 3.9 (3.2 to 4.7) | 1.6 (1.3 to 2.0) | Ref |
| Hospital deaths | 90 | 620 | 122 |
| PY at risk | 6 460 531 | 43 272 278 | 12 797 190 |
| Mortality rate per 100 000 PY | 1.39 | 1.43 | 0.95 |
| Crude rate ratio (95% CI) | 1.5 (1.1 to 1.9) | 1.5 (1.2 to 1.8) | Ref |
| Crude rate difference per 100 000 PY (95% CI) | 0.44 (0.11 to 0.77) | 0.48 (0.28 to 0.68) | Ref |
PY, person-years.