Table 1.
Characteristics of included Studies
| Study | N | Type of MCI/criteria | Outcome | Follow-up in months | N progressors (%) | Age of progressors M (SD) | % female for progressors | Education of progressors | Neuropsychological tests included in the analysis | Type of study |
|---|---|---|---|---|---|---|---|---|---|---|
| (Ahmed et al. 2008) | 18 | aMCI | AD | 12 | 7 (39) | 71.7 (6.8) | n.r. | 11.9 (1.6) | ● Addenbrooke’s Cognitive Examination ● Famous buildings, Associative Learning Battery ● Patterns, Associative Learning Battery ● CANTAB paired associate learning (short version) ● Graded naming test ● Animal fluency ● Trail making test, Part B ● Addenbrooke’s Cognitive Examination + CANTAB paired associate learning |
LP |
| (Albert et al. 2001) | 114 | QAD | AD | 36 | 23 (19) | 73 | 48 | n.r. | ● Trail making test, Part B + Figures WMS, Immediate recall + Self Ordering Test, total score | LP |
| (Anchisi et al. 2005) | 48 | aMCI | AD | 12 (median) | 14 (29) | 71.1 (3.9) | 64 | 9.1 (5.0) | ● CVLT, long delay recall | LP |
| (Arnaiz et al. 2001) | 20 | MCI, GDS = 3 | AD | 33.6 (14.6) | 9 (45) | 64.9 (8.3) | 33 | 11.9 (2.2) | ● Block design, WAIS-R | LP |
| (Babins et al. 2008) | 8a | aMCI | AD | 58.8 (13.6) | 41 (50) | 77.6 (5.7) | n.r. | 11.54 (3.6) | ● Clock drawing test, 18-point scoring system | LP |
| (Belleville et al. 2014b) | 92 | aMCI | cognitive decline and AD | 30.81 (20) | 49 AD +10 decliners MCI (55) | 70.5 (7.9) | 60 | 14.5 (4.4) | ● Macro Text, delayed recall ● RL/RI 16, free delayed recall ● Alpha span, items alpha recalled ● BORB, line judgement ● BORB, object decision ● D.O.80 ● Combination Macro Text, delayed recall + Free recall of words + D.O.80 + BORB line judgement + BORB object decision +alpha-span |
LP |
| (Buchhave et al. 2008) | 147 | aMCI | AD, VD and other dementia | 62.4 | 63 (43) | 74.6 (6.1) | 68 | n.r. | Cube copying, total score | LP |
| (Defrancesco et al. 2013) | 60 a | aMCI | AD | 18.3 (7.1) | 31 (52) | 76.3 (6.7) | 77 | 10.4 (3.5) | Combination CERAD word list recall + MMSE orientation | LR |
| (Didic et al. 2013) | 26 | sd-aMCI | AD | 42 (22.2) | 15 (58) | 71.8 (6.0) | 40 | 11 | ● FCSRT, free recall ● FCSRT, total recall ● FCSRT, total delayed recall ● Logical Memory WMS-III, Delayed recall ● Logical Memory WMS-III, Recognition ● Knowledge Public Events, free recall ● Knowledge Public Events, total recall ● Rey’s Figure, delayed recall ● DMS48, immediate recognition ● DMS48, delayed recognition ● Face recognition WMS-III ● Combination Logical Memory WMS-III, delayed recall + DMS48, immediate recognition |
LP |
| (Dierckx et al. 2009) | 31 | sd-aMCI | AD | 17 (2) | 7 (23) | 76.7 (4.9) | 29 | 12.7 (3.3) | ● MISplus, total delayed recall ● Visual association test, total |
LP |
| (Eckerstrom et al. 2013) | 42a | MCI (GDS = 3) | dementia and AD | 24 | 13 (31%) | 70.0 (6.5) | 69 | 10.0 (2.9) | ● RAVLT delayed recall ● Boston naming test ● VOSP Silhouettes |
LR |
| (Ewers et al. 2012) | 130 | aMCI | AD | 39.6b | 58 | 74.6 (7.3) | 33 | n.r. | ● RAVLT, delayed recall ● RAVLT, immediate recall@ ● RAVLT, delayed recognition ● Digit span, total score ● Trail making test, Part B ● Trail making test, Part Bb ● Category (vegetables) fluency |
ADNI |
| (Flicker et al. 1991) | 32 | MCI (GDS = 3) | GDS decline and AD | 25,32+/−1,08 | 16 (50) + 7 decliners | n.r. | n.r. | n.r. | ● Object function recognition ● Object identification |
LP |
| (Gallagher et al. 2010) | 182c | MCI | AD | 26 (17.5) | 75 (41) | 73.9 (5.9) | 53 | n.r. | ● Combination DWR, free recall + categoryfluency ● DWR-extended, free recallc ● DWR-extended, recognition c ● CAMCOG, total score c ● CAMCOG, orientation c ● CAMCOG, perception c ● CAMCOG, category fluency c ● CAMCOG, letter fluency c ● Boston Naming test c |
LR |
| (Gallagher et al. 2010) | ● Combination DWR free recall + DWR recognition | |||||||||
| (Galton et al. 2005) | 29 | QD | AD | 24 (5.4) | 11 (35) | 70.9 (8.9) | 46 | n.r. | ● Logical Memory WMS-R, immediate recall ● Logical Memory WMS-R, delayed recall ● Warrington’s recognition memory tests, short recognition memory test for words ● Warrington’s recognition memory tests, short recognition memory test for faces ● Doors test, total score ● Addenbrooke’s Cognitive Examination ● ADAS-Cog total ● Category fluency ● Graded naming test ● Cambridge Semantic Battery, Picture naming (64) |
LP |
| (Griffith et al. 2006) | 49d | sd-aMCI | AD | 24 | 13 (26) | 70.2 (6.7) | 77 | 13.5 (1.9) | ● Visual Reproduction WMS-III, percent retention ● Combination Dementia Rating Scale, initiation/perserveration + Visual Reproduction, percent retention |
LP |
| (Irish et al. 2011) | 15 | aMCI | AD | 22.4 (9.5) | 6 (38) | 71.8e (6.8) | 38e | 13.8e (4.7) | ● Face name association task, free delayed recall of names | LP |
| (Kluger et al. 1999) | 71 | MCI f (GDS = 3) | Declineg | 45.6f (26.4) | 47 (66) | 73.0f (9.1) | 61f | 13.4f (3.3) | ● Guild Paragraph, delayed recall | LR |
| (Lekeu et al. 2010) | 34 | aMCI | AD | 26.8 | 17 (50) | 72.0 (5.9) | 71 | 10.8 (2.5) | ● Rey’s figure, delayed recall | LP |
| (Marcos et al. 2006) | 82 | aMCI | AD | 36 | 38 (46) | 77.6 (6.1) | 68 | 84% <10 years | ● Blessed Dementia scale ● MMSE ● CAMCOG, total ● CAMCOG, perception ● CAMCOG, orientation ● Combination CAMCOG global score + CAMCOG memory + CAMCOG perception |
LP |
| (Mitchell et al. 2009) | 82 | MCI | AD | 24 | 35 (41) | n.r. | n.r. | n.r. | ● Combination Addenbrooke’s Cognitive Examination and/or CANTAB paired associate learning | LP |
| (Perri et al. 2007a) | 190 | sd-aMCI | AD | 24 | 79 (42) | 73,2+/−5,5 | 56 | 7,5+/−3,2 | ● Unrelated word list, immediate recall ● Related word list, immediate recall ● Unrelated word list, delayed recall ● Related word list, delayed recall ● Prose recall, immediate recall ● Prose recall, delayed recall ● Rey’s figure, immediate recall ● Rey’s figure, delayed recall ● CDR, mean sum boxes |
LP |
| (Richard et al. 2013) | 181 | aMCI | AD | 38.9 | 81 (45) | 74.4 (7.4) | 38 | 15.6 (3.0) | ● RAVLT Total recalla | ADNI |
| (Sarazin et al. 2007) | 217 | aMCI | AD | 31 (10.5) | 59 (26) | 74.8 (4.1) | 54 | n.r. | ● FCSRT, delayed free recall ● FCSRT, total delayed recall ● FCSRT, free recall ● FCSRT, total recall ● Similarities WAIS-R ● Benton visual retention test ● Double task Baddeley ● Serial digits ordering tests ● Digit symbol test WAIS-R ● Stroop test ● Trail Making test-Part A ● Trail Making test-Part B ● Naming-Deno 100 ● Letter (S) fluency ● Category (fruit) fluency |
LP |
| (Tabert et al. 2006) | 115h | MCI | AD | 21 (15) | 35 (30) | 72.7 (7.2) | 60 | 13.9 (4.5) | ● Combination SRT, total immediate recall + Digit symbol WAIS-R | LP |
| (Tierney et al. 1996) | 123 | CI | AD | 24 | 29 (24) | 73.9 (6.7) | n.r. | 13.5 (3.0) |
● RAVLT, delayed recall + Mental control WMSc | LP |
| (Venneri et al. 2011) | 25 | MCI | AD | 36 | 11 (44) | 72.45 (5.07) | 36% | 8.64 (4.58) | ● Category fluency ● Raven’s progressive matrices ● Paired associate Learning |
LP |
| (Visser et al. 2001) | 67 | MCI | AD | 60 | 23 (67) | 70.1 (6.6) | 52 | 10.8 (3.4) | ● RAVLT, delayed recall | LP |
N, sample size of MCI included in the meta-analysis; MCI, Mild cognitive impairment; M, Mean; SD, Standard deviation; aMCI, Amnestic MCI including single and multi-domain types; AD, Alzheimer’s disease; n.r., Not reported; LP, Longitudinal prospective study; QAD, Questionable AD; WMS, Wechsler memory scale (III = third version, R = revised); CVLT, California verbal learning test; GDS, Global deterioration scale; WAIS-R, Wechsler adult intelligence scale-revised; RL/RI 16, French version of the free and cued recall task; BORB, Birmingham object recognition battery; MEMO-Text, Text memory; D.0.80, Denomination 80 items; VD, Vascular dementia; LR, Longitudinal retrospective study; CERAD, Consortium to establish a registry for Alzheimer’s Disease; MMSE, Mini-mental state examination; sd-aMCI, Single domain amnestic MCI; CDR, Clinical Dementia rating scale; FCSRT, Free and Cued selective reminding test, DMS48, Delayed matching to sample − 48 items; MISplus, Memory impairment screen plus; RAVLT, Rey auditory verbal learning test; VOSP, Visual object and space perception; ADNI, Alzheimer’s disease neuroimaging initiative; DWR, Delayed word recall; CAMCOG, Cambridge cognitive examination; QD, Questionable dementia; ADAS-cog, Alzheimer’s disease assessment scale cognitive section, SRT, Buscke selective reminding test; CI, Cognitively impaired
@Data not included because used in another study
aData from convenience sample
bData analyzed for follow-up = 24 or 36 months
cSub-analysis was made for a subgroup of 106 participants with complete 3 year follow-up, N converters = 64 (60%)
dAmong the 49 participants, 11 converted at the 1 year follow-up (mean time = 13.04 +/− 2.1)
eDemographic data from all MCI participants
fDemographic data from participants with GDS = 1–3 at baseline
gGDS = 4 + AD criteria
hSub-sample from the total MCI population (n = 148) with mean time to conversion 21+/−15 months, n converters = 39