Cox proportional hazards model estimating the association between social relationship variables and incident dementia
| Variables | Categories | Model 1* | Model 2† | Model 3‡ |
| (n, %) | HR (95% CI) | HR (95% CI) | HR (95% CI) | |
| Married | Yes (10 232, 73.2) | 0.50 (0.46 to 0.54) | 0.85 (0.76 to 0.94) | 0.88 (0.79 to 0.99) |
| Contact (relatives) | Yes (12 990, 92.9) | 0.74 (0.64 to 0.87) | 0.85 (0.73 to 1.00) | 0.89 (0.76 to 1.05) |
| Contact (friends) | Yes (12 291, 87.9) | 0.55 (0.49 to 0.62) | 0.78 (0.69 to 0.88) | 0.83 (0.73 to 0.94) |
| Group participation | Yes (8671, 62.0) | 0.61 (0.56 to 0.67) | 0.85 (0.77 to 0.94) | 0.89 (0.80 to 0.98) |
| Work engagement | Yes (3480, 24.9) | 0.52 (0.47 to 0.59) | 0.85 (0.76 to 0.97) | 0.88 (0.77 to 0.99) |
| Support (family) | Yes (11 507, 82.3) | 0.68 (0.62 to 0.75) | 0.84 (0.76 to 0.94) | 0.88 (0.79 to 0.99) |
| Support (relatives) | Yes (7372, 52.7) | 0.92 (0.84 to 1.00) | 1.02 (0.93 to 1.11) | 1.03 (0.95 to 1.13) |
| Support (friends) | Yes (6121, 43.8) | 0.75 (0.69 to 0.82) | 0.96 (0.87 to 1.05) | 0.98 (0.89 to 1.08) |
*Unadjusted model.
†Association with each social variable and incident dementia is estimated. All covariates (age, gender, education, household income, Geriatric Depression Scale, subjective cognitive complaints, instrumental activities of daily living, stroke, diabetes, daily walking time and hobbies) are adjusted.
‡All social variables are simultaneously entered into the model with all covariates.