Table 1. The risk of incident dementia during follow-up in 888 participants aged 75 years and older without dementia at baseline.
| Characteristic | Subcategory, | No incident dementia n = 705 | Incident dementia n = 183 | p value | Univariate hazard ratio (95% CI) | p-value | Full models: hazard ratio (95% CI), fully adjusted for all variables | |||||
| Model I: | p value | Model II: | p value | Model III: | p value | |||||||
| Age, | mean (s.d.) | 80.6 (4.5) | 83.8 (4.7) | <0.001 | 1.16 (1.12–1.19) | <0.001 | 1.10 (1.06–1.13) | <0.001 | 1.09 (1.06–1.13) | <0.001 | 1.10 (1.06–1.13) | <0.001 |
| Gender, n (%) | Female | 499 (70.8) | 153 (83.6) | <0.001 | 1.74 (1.18–2.58) | 0.005 | 1.30 (0.82–2.04) | 0.263 | 1.28 (0.82–2.02) | 0.281 | 1.27 (0.81–2.00) | 0.294 |
| Educational level1, n (%) | Low | 444 (63.2) | 127 (69.4) | 0.170 | 1 | – | 1 | – | 1 | – | 1 | – |
| Middle | 165 (23.5) | 40 (21.9) | 0.84 (0.59–1.20) | 0.348 | 1.31 (0.91–1.89) | 0.151 | 1.31 (0.91–1.89) | 0.153 | 1.32 (0.91–1.90) | 0.142 | ||
| High | 94 (13.4) | 16 (8.7) | 0.56 (0.34–0.95) | 0.030 | 1.77 (1.00–3.15) | 0.051 | 1.79 (1.01–3.17) | 0.048 | 1.84 (1.04–3.27) | 0.038 | ||
| Marital status, n (%) | Married | 221 (31.3) | 29 (15.8) | <0.001 | 1 | – | 1 | – | 1 | 1 | ||
| Single | 65 (9.2) | 13 (7.1) | 1.39 (0.72–2.66) | 0.330 | 0.76 (0.38–1.54) | 0.448 | 0.76 (0.38–1.55) | 0.453 | 0.78 (0.39–1.59) | 0.496 | ||
| Divorced | 60 (8.5) | 15 (8.2) | 1.75 (0.94–3.26) | 0.080 | 1.13 (0.57–2.22) | 0.732 | 1.11 (0.56–2.19) | 0.760 | 1.11 (0.57–2.19) | 0.754 | ||
| Widowed | 359 (50.9) | 126 (68.9) | 2.46 (1.64–3.68) | <0.001 | 1.34 (0.85–2.12) | 0.213 | 1.33 (0.84–2.11) | 0.221 | 1.36 (0.86–2.16) | 0.186 | ||
| Performance in ADL/IADL | mean (s.d.) | 0.19 (0.30) | 0.40 (0.42) | <0.001 | – | – | – | – | – | – | – | – |
| per one point | – | – | – | 4.84 (3.58–6.55) | <0.001 | 2.75 (1.90–3.98) | <0.001 | 2.71 (1.86–3.94) | <0.001 | 2.66 (1.84–3.85) | <0.001 | |
| Cognitive state, MMSE | mean (s.d.) | 27.4 (1.9) | 25.9 (2.1) | <0.001 | - | - | - | - | - | - | - | - |
| per one point | – | – | – | 0.71 (0.67–0.76) | <0.001 | 0.76 (0.71–0.82) | <0.001 | 0.76 (0.71–0.82) | <0.001 | 0.76 (0.71–0.81) | <0.001 | |
| Depressive symptoms2 CES-D | mean (s.d.) | 14.3 (7.6) | 15.8 (7.0) | 0.015 | – | – | – | – | – | – | – | – |
| per one point | – | – | – | 1.03 (1.01–1.05) | 0.004 | 1.00 (0.98–1.02) | 0.629 | – | – | – | – | |
| Mood-relatedsymptoms | mean (s.d.) | 3.4 (2.6) | 4.1 (2.7) | 0.004 | – | – | – | – | – | – | – | – |
| per one point | – | – | – | 1.08 (1.03–1.14) | 0.002 | – | – | 1.00 (0.94–1.06) | 0.956 | – | – | |
| Motivation-related symptoms | mean (s.d.) | 1.9 (1.7) | 2.1 (1.8) | 0.241 | – | – | – | – | – | – | – | – |
| per one point | – | – | – | 1.06 (0.97–1.15) | 0.212 | – | – | 1.00 (0.90–1.10) | 0.951 | – | – | |
| Major depression (SCID, DSM-IV)3 | n (%) | 7 (1.0) | 4 (2.2) | 0.194 | 2.60 (0.97–7.02) | 0.059 | – | – | – | – | 2.75 (1.01–7.50) | 0.048 |
Abbreviations: ADL – Activities of daily living; CES-D – Center for Epidemiologic Studies Depression Scale; CI – Confidence interval; IADL – Instrumental activities of daily living; MMSE – Mini Mental State Examination; SCID – Structured Clinical Interview; s.d. – standard deviation.
Notes:
1
Based on the revised version of the international CASMIN educational classification;
2
128 participants (14.4%) with depressive symptoms at baseline (CES-D cut-off score 23);
3
11 participants (1.2%) with major depression at baseline.