Subgroup analyses by age, sex, research sites and region
| Subgroup | Prevalence (%) | 95% CI (%) | Heterogeneity | |
| I2 (%) | P value | |||
| Age | ||||
| 60–69 | 11.98 | 3.91 to 23.62 | 98.1 | 0.000 |
| 70–79 | 26.79 | 8.71 to 50.36 | 99.7 | 0.000 |
| 80–89 | 51.31 | 47.20 to 96.33 | 99.6 | 0.000 |
| ≥90 | 57.53 | 8.18 to 98.09 | 99.0 | 0.000 |
| Sex | ||||
| Females | 8.26 | 5.88 to 11.00 | 87.4 | 0.000 |
| Males | 18.65 | 0.83 to 51.61 | 99.9 | 0.000 |
| Research sites | ||||
| Health examination centre | 43.83 | 19.39 to 69.94 | 99.8 | 0.000 |
| Nursing homes | 16.26 | 4.55 to 33.29 | 93.2 | 0.000 |
| Community | 12.21 | 3.46 to 25.34 | 99.8 | 0.000 |
| Region | ||||
| Turkey, China | 24.34 | 14.03 to 36.38 | 99.6 | 0.000 |
| Norway, Denmark, Britain | 8.23 | 6.36 to 10.35 | 90.2 | 0.000 |