Table 1: Demographic characteristics and cognitive status of the sample by the Levels of NFI.
| Levels of NFI | 0-4 | 5-10 | 11-18 | ≥ 19 | P-value |
| Age | 77.03 (6.06) | 80.31 (6.32) | 82.34 (7.10) | 82.1 (7.22) | 0.001 |
| Male (%) | 99 (50.8) | 191 (47.6) | 100 (33) | 25 (25.5) | 0.001 |
| Education (years) | 10.63 (4.23) | 8.87 (3.74) | 8.28 (3.98) | 6.78 (3.94) | 0.001 |
| 3MS-CSHA1 | 88.73 (8.33) | 82.89 (9.6) | 78.48 (9.61) | 71.95 (9.63) | 0.001 |
| 3MS-CSHA2 | 85.34 (13.09) | 78.26 (15.32) | 67.03 (18.27) | 57.45 (22.15) | 0.001 |
| NFI; mean (SD) | 2.65 (1.22) | 7.18 (1.57) | 13.27 (2.26) | 22.28 (3.72) | 0.001 |