From: Attrition and bias in the MRC cognitive function and ageing study: an epidemiological investigation
 | Total | In wave 2 | Not in wave 2 | Reason not in wave 2 | ||
---|---|---|---|---|---|---|
 |  |  |  | Died | Refused | Moved |
Total | 13004 | 8826 | 4178 | 1502 | 2704 | 189 |
Centre: Cambridge | 2601 (20) | 1720 (19) | 881 (21) | 294 (20) | 601 (22) | 27 (14) |
   Gwynedd | 2625 (20) | 1703 (19) | 922 (22) | 296 (20) | 646 (23) | 38 (20) |
   Newcastle | 2524 (19) | 1707 (19) | 817 (19) | 301 (20) | 525 (19) | 48 (25) |
   Nottingham | 2514 (19) | 1733 (20) | 781 (19) | 310 (21) | 462 (17) | 39 (21) |
   Oxford | 2740 (21) | 1963 (22) | 777 (18) | 301 (20) | 470 (17) | 37 (20) |
Women | 7847 (60) | 5230 (59) | 2617 (63) | 826 (55) | 1818 (67) | 105 (56) |
Age: [Median (IQR)] | 75 (70–80) | 74 (69–79) | 77 (71–82) | 80 (75–85) | 75 (70–80) | 75 (69–81) |
Married or cohabiting | 6445 (50) | 4519 (52) | 1926 (47) | 579 (41) | 1347 (51) | 78 (41) |
Residential Home | 593 (5) | 251 (3) | 342 (8) | 268 (18) | 98 (4) | 7 (4) |
Social class IV/V | 2547 (20) | 1567 (18) | 980 (25) | 343 (25) | 668 (26) | 29 (16) |
Caucasian†| 9512 (99) | 6458 (99) | 3054 (99) | 1058 (99) | 2014 (99) | 144 (99) |
= 9 years of education | 7995 (63) | 5279 (60) | 2731 (69) | 920 (69) | 1850 (70) | 111 (60) |
Living alone‡ | 4890 (40) | 3386 (39) | 1504 (39) | 540 (44) | 960 (37) | 80 (44) |
Ever smoked | 8260 (65) | 5709 (66) | 2551 (65) | 910 (69) | 1628 (62) | 134 (74) |
MMSE < 18 | 703 (5) | 269 (3) | 434 (11) | 290 (21) | 186 (7) | 9 (5) |
MMSE [Median (IQR)] | 27 (24–28) | 27 (25–29) | 25 (22–28) | 24 (20–27) | 25 (22–28) | 27 (24–29) |
ADL 11 and above | 1488 (12) | 770 (9) | 718 (18) | 438 (34) | 333 (13) | 23 (13) |
ADL [Median (IQR)] | 2 (0–6) | 1 (0–5) | 3 (0–8) | 6 (2–13) | 2 (0–6) | 1.5 (0–6) |
Poor self perceived health | 4058 (32) | 2520 (29) | 1538 (39) | 670 (51) | 925 (36) | 52 (28) |
Sight or hearing problem | 4059 (31) | 2630 (30) | 1429 (35) | 606 (42) | 859 (32) | 62 (33) |
Screening AGECAT O3+ | 815 (6) | 333 (4) | 482 (12) | 317 (21) | 212 (8) | 15 (8) |
Self reported depression | 1122 (9) | 789 (9) | 333 (8) | 94 (7) | 226 (9) | 26 (14) |
Chronic disease* | 7989 (61) | 5473 (62) | 2516 (60) | 933 (62) | 1582 (59) | 122 (65) |
Dementia prevalence | 8.4 (7–9) | 6.0 (5–7) | 13.8 (12–16) | 27.7 (23–33) | 5.9 (4–8) | 16.8 (5–45) |
Depression prevalence | 9.3 (8–11) | 9.3 (8–11) | 9.2 (7–12) | 14.8 (11–20) | 5.8 (4–8) | 13.4 (4–38) |