Table 2. Relative risks (RRs) and statistical significance (as apices) of detecting incidence rates different from that arbitrarily fixed in “index year”.
| 2012 vs. 2011 | 2013 vs. 2012 | 2014 vs. 2013 | |
| Abruzzo | 1.0275d | 0.9954 | 0.9839 |
| Aosta Valley | 1.0127 | 0.9904 | 0.9942 |
| Apulia | 1.0102 | 0.9998 | 0.9904 |
| Basilicata | 1.0172 | 1.0024 | 0.9962 |
| Calabria | 1.0271d | 1.0001 | 0.9887 |
| Campania | 1.0121d | 0.9991 | 0.9829d |
| Emilia Romagna | 1.021d | 0.9917 | 0.9845d |
| Friuli-Venezia Giulia | 1.0148 | 0.9967 | 0.9939 |
| Lazio | 1.0416c,d | 0.9897 | 0.9467c,d |
| Liguria | 1.0315d | 1.0014 | 0.9832 |
| Lombardy | 1.0224d | 0.9904d | 0.9821d |
| Marche | 1.016 | 0.9971 | 0.9949 |
| Molise | 1.0212 | 0.9994 | 0.9956 |
| Piedmont | 1.0229d | 0.9963 | 0.9859d |
| Sardinia | 1.0229d | 0.9985 | 0.9859 |
| Sicily | 1.0102 | 0.9999 | 0.9814d |
| Tuscany | 1.0224d | 0.9932 | 0.9846d |
| Trentino-Alto Adige | 1.0073 | 0.9900 | 0.9886 |
| Umbria | 1.0263 | 0.9966 | 0.9883 |
| Veneto | 1.0173d | 0.9942 | 0.9909 |
| Italy | 1.0207c,d | 0.9951d | 0.9819c,d |
Note: Statistically significant difference with “index year” fixed at incidence rate: (a) 1/100,000; (b) 10/100,000; (c) 100/100,000 and (d) 1,000/100,000.