Table 2.
Details and characteristics of the studies included in the systematic review
| First author (year) | Location | Sample size | Study population | Mean age (SD) | Female (%) | Study design | Setting | Language of development | Language of validation |
|---|---|---|---|---|---|---|---|---|---|
| Allison et al. (2019) [30] | USA | 91 | Cognitively healthy adults | 69 (6) | 54 (59.34) | Cross-sectional | Laboratory | English | English |
| Avila-Villanueva et al. (2016) [31] | Spain | 844 | Cognitively healthy adults (n = 766); MCI (n = 78) | Cognitively healthy = 74.07 (3.80); MCI = 76.08 (4.06) | Cognitively healthy = 63% female; MCI = 50%female | Longitudinal | Research setting (unspecified) | English | Spanish |
| Chipi et al. (2018) [32] | Italy | 257 | Cognitively healthy adults | 70.9 (5.1) | 158 (61.2%) | Cross-sectional | Memory clinic | English | Italian |
| Crook et al. (1992) [33] | USA | 232 | Cognitively healthy adults | 59.2 (6.9) | 117 (50.43%) | Clinical trial | Unspecified | English | English |
| Crowe et al. (2006) [34] | USA | 55 | MCI | 76 (NA) | 39 (71%) | Longitudinal | Unspecified | English | English |
| Crowe et al. (2006) [34] | USA | 55 | MCI | 76 (NA) | 39 (71%) | Longitudinal | Unspecified | English | English |
| Gifford et al. (2015) [35] | USA | 191 | Cognitively healthy adults (n = 115); MCI (n = 43); Other (n =33) | Cognitively healthy = 75.9 (7.5); MCI = 77.0 (6.5); others = 78.5 (8.5) | Cognitively healthy = 72.24 (63%); MCI = 21.9 (51%); others = 19.14 (58%) | Longitudinal | Unspecified | English | English |
| Gilewski et al. (1990) [36] | USA | 778 | Cognitively healthy adults | 56.9 (20.8) | 435 (55.91%) | Cross-sectional/longitudinal | Unspecified | English | NA |
| La Joie et al. (2016) [37] | France | 185 | Cognitively healthy (n = 74); MCI (n = 78); SCD (n = 33) | Cognitively healthy = 69 (7.2); MCI = 73 (7.2); SCD = 68 (7.3) | Cognitively healthy = 40 (54%); MCI = 38 (49%); SCD = 14 (42%) | Cross-sectional | Memory clinic | English | French |
| Lubitz et al. (2018) [38] | Germany | 734 above 65 = 83.67 (11.4%) | Cognitively healthy adults | 43.15 (17.17); | 401 (62.26%) of subsample of 644 participants | Longitudinal | Community-based | German | German |
| Papaliagkas et al. (2017) [39] | Greece |
295 older adults (n = 53) Older-old adults (n = 28) |
Cognitively healthy adults |
Older adults = 69.9 (3.6) Older-old adults = 83.5 (3.3) |
Older adults = 31 (56.6%) Older-old adults = 18 (64.3%) |
Cross-sectional | Unspecified “quiet and comfortable environment” | English | Greek |
| Papaliagkas et al. (2017) [39] | Greece |
295 older adults (n = 53) Older-old adults (n = 28) |
Cognitively healthy adults |
Older adults = 69.9 (3.6) Older-old adults = 83.5 (3.3) |
Older adults = 31 (56.6%) Older-old adults = 18 (64.3%) |
Cross-sectional | Unspecified “quiet and comfortable environment” | English | Greek |
| Rami et al. (2014) [40] | Spain | 397 | Cognitively healthy (n = 124); MCI (n = 83), AD (n = 46); SCD (n = 144) | Cognitively healthy = 60.2 (9.2); P-SCD = 56.8 (10.4); C-SCD = 67.0 (8.9); MCI = 70.5 (9.2); AD = 74.5 (8.8) | Cognitively healthy = 66 (59%); P-SCD = 33 (58%); C-SCD = 58 (71%); MCI = 39 (49%); AD = 29 (64%) | Cross-sectional | Unspecified | Spanish | Spanish |
| Rattanabannakit et al. (2016) [41] | USA | 267 | Cognitively healthy (n = 149); MCI (96); AD (n = 22) | 67.8 (11.2) | 138 (51.7) | Cross-sectional | Memory clinic | English | English |
| Valech et al. (2018) [42] | Spain | 68 | Cognitively healthy (n = 37); SCD (n = 31) | Cognitively healthy = 64.49 (6.89); P-SCD = 59.33 (5.82); C-SCD = 65.72 (7.02) | Cognitively healthy = 23 (62.2%); P-SCD = 6 (100%); C-SCD = 17 (68.0%) | Cross-sectional | Memory clinic/home | Spanish | Spanish |
| Vestergren et al. (2011) [43] | Sweden | 370 | Cognitively healthy adults | 65 (15) | 194 (52.7) | Longitudinal | Home | Swedish | Swedish |
| Vestergren et al. (2012) [44] | Sweden | 1115 | Cognitively healthy adults | 63.0 (14.5) | 598 (53.7) | Longitudinal | Unspecified | Swedish | Swedish |
| Youn et al. (2009) [45] | South Korea | 1651 | Cognitively healthy (n = 1464); AD (n = 187) | 74.3 (8.2) | 945 (57.3) | Longitudinal | Unspecified | Korean | Korean |
Abbreviations: AD Alzheimer’s disease, MCI mild cognitive impairment, SCD subjective cognitive decline, P-SCD SCD sample from the population, C-SCD SCD sample from clinical settings