| Cases,n (%) | Controls,n (%) | p Value* | |
| Gender | |||
| Male | 1067 (87) | 1105 (87) | |
| Female | 152 (13) | 166 (13) | 0.6585 |
| Age, mean (SD) | 66 (10) | 65 (10) | 0.0023 |
| Subjects per region | |||
| Barcelona | 229 (19) | 247 (19) | |
| Vollès, Bages | 188 (15) | 190 (15) | |
| Alicante | 89 (7) | 84 (7) | |
| Tenerife | 219 (18) | 226 (18) | |
| Asturias | 495 (41) | 524 (41) | 0.9592 |
| Race | |||
| White | 1214 (99.6) | 1270 (99.9) | |
| Non-white | 5 (0.4) | 1 (0.1) | 0.0917 |
| Educational level | |||
| Less than primary school | 563 (46) | 592 (47) | |
| Primary school | 470 (39) | 491 (39) | |
| High school/higher education | 166 (14) | 164 (13) | |
| Other | 15 (1) | 15 (1) | 0.9658 |
| Smoking | |||
| Never smokers | 166 (14) | 367 (29) | |
| Occasional smokers | 52 (4) | 97 (8) | |
| Former smokers | 470 (39) | 475 (37) | |
| Current smokers | 529 (43) | 326 (26) | <0.001 |
*p Value from the χ2 test; SD, standard deviation.