Risk factors | No. of studies | Statistical data | Heterogeneity | ||||
---|---|---|---|---|---|---|---|
OR | 95% CI | p value | I2 | Q value | p value | ||
Demographic variables | Â | Â | Â | Â | Â | Â | Â |
Age (year) | 5 | 1.007 | 0.984–1.031 | 0.546 | 72.592 | 14.594 | 0.723 |
Sex (Ref. Male) | 5 | 1.198 | 0.618–2.324 | 0.593 | 93.253 | 59.282 |  < 0.001 |
Ethnicity (Ref. Non-White) [28] | 1 | 1.410 | 1.130–1.740 | 0.002 |  |  |  |
Marital status (Ref. Married) | 2 | 1.407 | 0.867–2.281 | 0.167 | 48.124 | 1.928 | 0.165 |
Employment status (Ref. Working) | 2 | 1.389 | 0.977–2.415 | 0.244 | 62.742 | 2.684 | 0.101 |
Educational level (Ref. College and above) | 2 | 1.620 | 1.136–2.309 | 0.008 | 0 | 0.991 | 0.320 |
Economic status of the family (Ref. High income)  Middle income  Low income | 2 2 | 1.868 3.212 | 1.194–2.921 1.365–7.557 | 0.006 0.008 | 0 32.941 | 0.749 1.491 | 0.387 0.222 |
Health-related variables | Â | Â | Â | Â | Â | Â | Â |
Multimorbidity (number of morbidities) [28] | 1 | 1.090 | 0.970–1.230 | 0.140 |  |  |  |
BMI (Ref. < 30 kg m−2) [28] | 1 | 1.200 | 0.980–1.480 | 0.080 |  |  |  |
Diabetes duration (year) [17] | 1 | 1.270 | 1.050–1.550 | 0.016 |  |  |  |
HbA1c (%) [5] | 1 | 1.015 | 0.914–1.127 | 0.779 |  |  |  |
Cognitive function (MMSE score) [40] | 1 | 2.586 | 1.751–3.781 |  < 0.001 |  |  |  |
Social variables | Â | Â | Â | Â | Â | Â | Â |
Living alone (Ref. Yes) | 2 | 3.359 | 1.208–9.342 | 0.020 | 83.661 | 6.120 | 0.013 |
Previous experience of loneliness (Ref. None) [28] | 1 | 7.430 | 5.750–9.610 |  < 0.001 |  |  |  |
Social isolation (Social isolation index) [5] | 1 | 0.947 | 0.719–1.259 | 0.707 |  |  |  |
Psychological variable | Â | Â | Â | Â | Â | Â | Â |
Depression (Depression score) | 2 | 1.223 | 1.173–1.274 |  < 0.001 | 0 | 9.466 |  < 0.001 |