Table 1.
Characteristics of participants by cognitive impairment definition
| All participants (n=5687) |
Participants with cognitive impairment |
||||||||
|---|---|---|---|---|---|---|---|---|---|
| Definition 1 (n=821) | Definition 2 (n=1485) | Definition 3 (n=338) | Definition 4 (n=837) | Definition 5 (n=347) | Definition 6 (n=826) | Definition 7 (n=354) | |||
| Demographics | |||||||||
| Age, years | 65·7 (5·9) | 65·8 (5·9) | 67·0 (6·0) | 67·2 (6·0) | 66·0 (6·0) | 67·2 (6·1) | 65·8 (6·1) | 67·2 (6·1) | |
| Sex | |||||||||
| Female | 1552 (27·3%) | 264 (32·2%) | 454 (30·6%) | 113 (33·4%) | 253 (30·2%) | 108 (31·1%) | 241 (29·2%) | 109 (30·8%) | |
| Male | 4135 (72·7%) | 557 (67·8%) | 1031 (69·4%) | 225 (66·6%) | 584 (69·8%) | 239 (68·9%) | 585 (70·8%) | 245 (69·2%) | |
| Education | |||||||||
| Lower secondary school or less | 2374 (41·7%) | 487 (59·3%) | 649 (43·7%) | 191 (56·5%) | 347 (41·5%) | 150 (43·2%) | 400 (48·4%) | 171 (48·3%) | |
| Higher secondary school | 1556 (27·4%) | 190 (23·1%) | 394 (26·5%) | 85 (25·2%) | 222 (26·5%) | 96 (27·7%) | 205 (24·8%) | 86 (24·3%) | |
| University degree or higher | 1757 (30·9%) | 144 (17·6%) | 442 (29·8%) | 62 (18·3%) | 268 (32·0%) | 101 (29·1%) | 221 (26·8%) | 97 (27·4%) | |
| Occupation | |||||||||
| Low | 609 (10·7%) | 248 (30·2%) | 190 (12·8%) | 98 (29·0%) | 226 (27·0%) | 86 (24·8%) | 119 (14·4%) | 56 (15·8%) | |
| Intermediate | 2530 (44·5%) | 425 (51·8%) | 619 (41·7%) | 154 (45·6%) | 401 (47·9%) | 151 (43·5%) | 356 (43·1%) | 141 (39·8%) | |
| High | 2548 (44·8) | 148 (18·0%) | 676 (45·5%) | 86 (25·4%) | 210 (25·1%) | 110 (31·7%) | 351 (42·5%) | 157 (44·4%) | |
| Cognitive scores | |||||||||
| Scores at baseline (2007–09) | |||||||||
| Memory (range 0–20) | 6·21 (2·21) | 4·32 (2·21) | 5·51 (2·19) | 3·86 (2·22) | 4·38 (2·29) | 3·98 (2·35) | 4·48 (2·25) | 4·05 (2·30) | |
| Language (range 0–35) | 15·34 (3·46) | 11·64 (3·44) | 14·56 (3·63) | 11·56 (3·97) | 11·78 (3·48) | 11·63 (3·96) | 12·03 (3·51) | 11·83 (3·85) | |
| Executive function (range 0–65) | 43·92 (10·82) | 30·38 (11·34) | 41·31 (11·27) | 31·05 (11·78) | 31·35 (11·74) | 32·14 (12·04) | 33·06 (11·84) | 33·30 (11·86) | |
| Proportion with MMSE <24 (n=45) | 0·8% | 5·5% | 3·0% | 13·3% | 5·4% | 13·0% | 5·5% | 12·7% | |
| 10-year change | |||||||||
| Memory | −0·32 (1·15) | −0·56 (1·39) | −1·05 (1·46) | −1·23 (1·58) | −0·56 (1·39) | −1·22 (1·59) | −0·62 (1·35) | −1·27 (1·50) | |
| Language | −0·37 (0·79) | −0·49 (1·01) | −0·87 (1·02) | −0·92 (1·27) | −0·51 (1·01) | −0·94 (1·26) | −0·54 (1·02) | −0·97 (1·25) | |
| Executive function | −0·27 (0·60) | −0·45 (0·69) | −0·60 (0·79) | −0·78 (0·84) | −0·45 (0·69) | −0·75 (0·85) | −0·48 (0·70) | −0·79 (0·85) | |
Data are mean (SD), n (%), or %. The definitions of cognitive impairment are as follows: (1) age and sex threshold for poor cognitive performance; (2) cognitive decline; (3) age and sex threshold for poor cognitive performance plus cognitive decline; (4) age, sex, and education threshold for poor cognitive performance; (5) age, sex, and education threshold for poor cognitive performance plus cognitive decline; (6) age, sex, and occupation threshold for poor cognitive performance; and (7) age, sex, and occupation threshold for poor cognitive performance plus cognitive decline. MMSE=Mini Mental State Examination.