Table 2.
Association between combination of social isolation and living alone and all-cause mortality.
| Number of events | IR* | Crude model | Adjusted model 1 | Adjusted model 2 | HR (95% CI) | p value | HR (95% CI) | p value | HR (95% CI) | p value | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Social isolation × living alone | ||||||||||||||
| No social isolation × Not living alone | 60 | 12.2 | Reference | Reference | Reference | |||||||||
| No social isolation × Living alone | 14 | 8.7 | 0.71 (0.40–1.27) |
0.25 | 0.86 (0.47–1.57) |
0.62 | 0.81 (0.44–1.49) |
0.50 | ||||||
| Social isolation × Not living alone | 31 | 22.3 | 1.86 (1.20–2.87) |
<0.01 | 1.47 (0.94–2.29) |
0.08 | 1.41 (0.90–2.20) |
0.13 | ||||||
| Social isolation × Living alone | 13 | 37.6 | 3.14 (1.72–5.72) |
<0.01 | 2.47 (1.33–4.60) |
<0.01 | 2.08 (1.08–4.00) |
0.03 | ||||||
| Social isolation (defined as Low frequency of face to face contact) × living alone | ||||||||||||||
| No social isolation × Not living alone | 41 | 12.8 | Reference | Reference | Reference | |||||||||
| No social isolation × Living alone | 8 | 7.2 | 0.56 (0.26–1.19) |
0.13 | 0.66 (0.30–1.42) |
0.28 | 0.62 (0.28–1.35) |
0.23 | ||||||
| Social isolation × Not living alone | 50 | 16.1 | 1.26 (0.84–1.91) |
0.27 | 1.06 (0.70–1.61) |
0.78 | 1.04 (0.69–1.59) |
0.84 | ||||||
| Social isolation × Living alone | 19 | 22.7 | 1.78 (1.04–3.07) |
0.04 | 1.77 (1.02–3.09) |
0.04 | 1.53 (0.86–2.72) |
0.15 | ||||||
| Social isolation (defined as Low frequency of non-face to face contact) × living alone | ||||||||||||||
| No social isolation × Not living alone | 42 | 10.6 | Reference | Reference | Reference | |||||||||
| No social isolation × Living alone | 13 | 9.1 | 0.86 (0.46–1.61) |
0.64 | 1.01 (0.53–1.93) |
0.98 | 0.95 (0.50–1.82) |
0.89 | ||||||
| Social isolation × Not living alone | 49 | 21.1 | 2.03 (1.34–3.06) |
<0.01 | 1.67 (1.10–2.54) |
0.02 | 1.63 (1.07–2.48) |
0.02 | ||||||
| Social isolation × Living alone | 14 | 26.7 | 2.56 (1.40–4.68) |
<0.01 | 2.31 (1.24–4.28) |
0.01 | 1.98 (1.04–3.77) |
0.03 | ||||||
IR, incidence rate; CI, confidence interval; HR, hazard ratio; SI, social isolation; LA, living alone; BMI, body mass index; IADL, instrumental activity of daily living; MMSE, mini-mental state examination. Adjusted model 1: age; sex, BMI, self-rated health, number of comorbidities, and IADL. Adjusted model 2: Adjusted model 1+ depressive symptoms, subjective financial status, education years, slow gait speed, and cognitive impairment. Incidence rate* = incidence rate per 1,000 person-years.