Associations between latitude and time-adjusted age-standardised prevalence for the Italian, Western Europe and Europe regions, and with adjustment for HLA-DRB1 frequencies
| Region | No of age-standardised prevalence estimates | Slope 95% CI* |
| Italian region | ||
| All prevalence estimates | 31 | −11.59 (−20.17 to −3.02)† |
| Adjusted for HLA-DRB1§ | 31 | 5.99 (−22.94 to 34.91) |
| Western Europe | ||
| All prevalence estimates | 114 | 9.27 (4.23 to 14.33)‡ |
| Only those with HLA-DRB1 data | 99 | 7.70 (3.19 to 12.22)‡ |
| Adjusted for HLA-DRB1§ | 99 | 7.97 (3.11 to 12.84)‡ |
| Europe | ||
| All prevalence estimates | 162 | 5.57 (2.34 to 8.80)‡ |
| Only those with HLA-DRB1 data | 146 | 5.03 (1.61 to 8.46)‡ |
| Adjusted for HLA-DRB1§ | 146 | 6.71 (2.43 to 10.98)‡ |
* Slope (95% CI)=change in prevalence/100 000 per degree of latitude (95% CI).
† Statistically significant (p<0.05).
‡ Statistically significant (p<0.001).
§ Adjustment for HLA-DRB1 allele frequencies includes adjustment for HLA-DRB1*01, *03, *11, *14 and *15.