Table 1.
General Characteristics of the Studies Included
| Authors | Year | Country | Setting | Design | n | Age in years, mean ± SD | Prevalence figure |
| Gobbens et al1 | 2010 | The Netherlands | community-dwelling | cross-sectional | 479 | ≥ 75 years, 80.3 ± 3.8 | 47.1% |
| Metzelthin et al36 | 2010 | The Netherlands | community-dwelling | cross-sectional | 532 | ≥ 70 years, 77.2 ± 5.5 | 40.2% |
| Gobbens et al42 | 2012 | The Netherlands | community-dwelling | longitudinal | 484 | ≥ 75 years, 80.3 ± 3.8 | - |
| Daniels et al37 | 2012 | The Netherlands | community-dwelling | longitudinal | 430 | ≥ 70 years, 77.2 ± 5.5 | 40.2% |
| Gobbens et al40 | 2013 | The Netherlands | community-dwelling | cross-sectional | 1,031 | ≥ 65 years, 73.4 ± 5.8 | 27.7% |
| Theou et al46 | 2013 | Eleven European countries, including the Netherlands | community-dwelling | longitudinal | 27,527 | ≥ 50 years, 65.3 ± 10.5 | 29.2%*** |
| Santiago et al7 | 2013 | Brazil | community-dwelling | cross-sectional | 219 | ≥ 60 years, sample 1: 69.8 ± 7.8 and sample 2: 71.3 ± 8.0 |
35.6% (sample 1); 31.7% (sample 2) |
| Andreasen et al8 | 2014 | Denmark | community-dwelling***** | cross-sectional**** | 13; 21 | 75.9 ± 6.9; 80.6 ± 6.5 | - |
| Uchmanowicz et al11 | 2014 | Poland | community-dwelling | cross-sectional | 100 | ≥ 60 years, 68.2 ± 6.5 | 40% |
| Gobbens & Van Assen41 | 2014 | The Netherlands | community-dwelling | longitudinal | 484 | ≥ 75 years, 80.3 ± 3.8 | - |
| Mulasso et al9 | 2015 | Italy | community-dwelling | cross-sectional | 267 | ≥ 65 years, 73.4 ± 6.0 | 44.6% |
| Gobbens et al39 | 2015 | The Netherlands | assisted living facilities | cross-sectional | 221 | ≥ 55 years, 84.8 ± 8.9 | 76.5% |
| Coelho et al10 | 2015 | Portugal | community-dwelling | cross-sectional | 252 | ≥ 65 years, 79.2 ± 7.3 | 54.8* |
| Andreasen et al48 | 2015 | Denmark | community-dwelling****** | cross-sectional**** | 14 | ≥ 65 years, 80.6 | - |
| Uchmanowicz et al50 | 2016 | Poland | community-dwelling | cross-sectional | 212 | ≥ 60 years, 70.6 ± 7.2 | 44.1% |
| Freitag et al12 | 2016 | Germany | community-dwelling | cross-sectional | 210 | ≥ 64 years, sample 1: 76.9 ± 5.7 and sample 2: 72.5 ± 5.5 | 46.7% (sample 1); 32% (sample 2) |
| Dong et al13 | 2017 | China | community-dwelling | cross-sectional | 917 | ≥ 60 years, 68.6 ± 6.6 | 12.4% |
| Renne & Gobbens45 | 2018 | The Netherlands | community-dwelling | cross-sectional | 241 | ≥ 70 years, 76.5 ± 5.1 | 32.8% |
| Santiago et al51 | 2018 | Brazil | community-dwelling******* | longitudinal | 963 | ≥ 60 years, 70.5 ± 8.2 | 44.2% |
| Vrotsou et al14 | 2018 | Spain | community-dwelling | cross-sectional | 856 | ≥ 70 years, 78.1 ± 4.9 | - |
| Topcu et al15 | 2019 | Turkey | geriatrics outpatient clinic | cross-sectional | 198 | ≥ 70 years, 77.7 ± 5.5 | 63.6% |
| Op Het Veld et al44 | 2019 | The Netherlands | community-dwelling | longitudinal | 2,420 | ≥ 65 years, 76.3 ± 6.6 | - |
| Op Het Veld et al43 | 2019 | The Netherlands | community-dwelling | longitudinal | 2,420 | ≥ 65 years, 76.3 ± 6.6 | 64.8%** |
| Alqahtani et al52 | 2020 | Saudi Arabia | community-dwelling******** | cross-sectional | 84 | ≥ 65 years, 72.0 ± 4.7 | 28.0% |
| Gobbens et al38 | 2020 | The Netherlands | community-dwelling | longitudinal | 180 | ≥ 70 years, 76.3 ± 5.1 | 29.4% |
| Gobbens & Andreasen49 | 2020 | Denmark | acutely admitted patients | longitudinal | 1,328 | ≥ 65 years, 76.9 ± 7.5 | 53.1% |
| Zhang et al47 | 2020 | The Netherlands, Spain, Greece, Croatia, United Kingdom | community-dwelling | cross-sectional | 2,250 | ≥ 70 years, 79.7 ± 5.7 | - |
Notes: *Cut-off for frailty was 6; **This study was conducted among pre-frail and frail individuals; ***This study did not use the original TFI; ****Cross-sectional qualitative research; *****Acutely admitted to hospital; ******Acutely admitted discharged to their own home; *******Users of primary health care services; ********in senior-living facilities, visiting outpatient clinic.
Abbreviation: SD, standard deviation.