Table 2. Participating hospitals and population coverage by region.
| Regions | Eligible hospitals | Participatinghospitals | Population assigned for admission | Total population | Population coveredby the study |
| Andalusia | 31 | 17 (55%) | 4882253 | 8150467 | 60% |
| Aragon | 10 | 2 (20%) | 666761 | 1313735 | 51% |
| Asturias | 9 | 5 (56%) | 942376 | 1058923 | 89% |
| Balearic Islands | 8 | 6 (75%) | 1025658 | 1070066 | 96% |
| Basque Country | 11 | 11 (100%) | 2045163 | 2136061 | 96% |
| Canary Islands | 8 | 4 (50%) | 1432866 | 2076585 | 69% |
| Cantabria | 4 | 3 (75%) | 560406 | 576418 | 97% |
| Castile-La Mancha | 15 | 7 (47%) | 1546687 | 2022647 | 76% |
| Castile and León | 15 | 13 (87%) | 2500503 | 2510545 | 99% |
| Catalonia | 27 | 10 (37%) | 3006371 | 7290292 | 41% |
| Extremadura | 10 | 3 (30%) | 630481 | 1080439 | 58% |
| Galicia | 15 | 9 (60%) | 2118741 | 2738930 | 77% |
| La Rioja | 2 | 2 (100%) | 307676 | 315718 | 97% |
| Madrid | 20 | 15 (75%) | 5317786 | 6295011 | 84% |
| Murcia | 10 | 4 (40%) | 833349 | 1433383 | 58% |
| Navarre | 4 | 4 (100%) | 563900 | 596236 | 95% |
| Valencia | 26 | 14 (54%) | 3363995 | 4991789 | 67% |
| TOTAL | 225 | 129 (57%) | 31744972 | 45657245 | 70% |