Characteristics of patients in dementia cohort and subset treated with memantine, AChEI and the combination of memantine and AChEI
| Complete dementia cohort | Dementia cohort | Dementia cohort | Matched control cohort | Memantine subcohort | AChEI subcohort | Memantine plus AChEI subcohort | |
|---|---|---|---|---|---|---|---|
| Study period | 1995–2011 | 1995 | 2011 | 1995–2011 | 2003–2011 | 2003–2011 | 2003–2011 |
| Total | 50 439 | 879 | 3108 | 50 439 | 669 | 10 794 | 379 |
| Males | 17 432 (34.6) | 304 (34.6) | 1170 (37.6) | 17 432 (34.6) | 243 (36.3) | 3855 (35.7) | 156 (41.2) |
| Age mean±SD | 82.0±7.3 | 81.7±7.3 | 82.5±7.4 | 82.0±7.3 | 79.9±7.5 | 79.4±7.0 | 76.4±7.1 |
| Median age | 83 | 82 | 83 | 83 | 80 | 80 | 77 |
| Age | |||||||
| 60–64 | 896 (1.8) | 9 (1.0) | 48 (1.5) | 896 (1.8) | 25 (3.7) | 324 (3.0) | 16 (4.2) |
| 65–69 | 2058 (4.1) | 50 (5.7) | 118 (3.8) | 2058 (4.1) | 43 (6.4) | 670 (6.2) | 52 (13.7) |
| 70–74 | 4798 (9.5) | 89 (10.1) | 287 (9.2) | 4798 (9.5) | 77 (11.5) | 1502 (13.9) | 73 (19.3) |
| 75–80 | 9610 (19.1) | 161 (18.3) | 510 (16.4) | 9610 (19.1) | 150 (22.4) | 2608 (24.2) | 111 (29.3) |
| 80–84 | 13 383 (26.5) | 243 (27.6) | 812 (26.1) | 13 383 (26.5) | 194 (29.0) | 3112 (28.8) | 76 (20.1) |
| 85–90 | 12 414 (24.6) | 206 (23.4) | 817 (26.3) | 12 414 (24.6) | 118 (17.6) | 1978 (18.3) | 41 (10.8) |
| ≥90 | 7280 (14.4) | 121 (13.8) | 516 (16.6) | 7280 (14.4) | 62 (9.3) | 600 (5.6) | 10 (2.6) |
| First recording of dementia after index prescription of antidementia drug (%) | 38 (5.7) | 948 (8.8) | 14 (3.7) | ||||
| Duration of dementia at time of first use of antidementia drug (mean years±SD | 1.4±1.7 | 0.7±1.1 | 2.7±2.0 | ||||
| Referral to specialist* in previous 6 months | 25 205 (50.0) | 224 (25.5) | 2010 (64.7) | 1265 (2.5) | 454 (67.9) | 6549 (60.7) | 173 (45.6) |
| Previous use of memantine | 0 (0.0) | 9 (0.1) | 35 (9.2) | ||||
| Previous use of AChEI | 119 (17.8) | 0 (0.0) | 342 (90.2) | ||||
| Use of antipsychotics at or before index day | |||||||
| Index day | 6289 (12.5) | 175 (19.9) | 231 (7.4) | 1322 (2.6) | 175 (26.2) | 1143 (10.6) | 89 (23.5) |
| 1–182 days | 7394 (14.7) | 197 (22.4) | 300 (9.7) | 2439 (4.8) | 182 (27.2) | 1325 (12.3) | 108 (28.5) |
| 183–365 days | 4950 (9.8) | 135 (15.4) | 225 (7.2) | 2403 (4.8) | 128 (19.1) | 906 (8.4) | 80 (21.1) |
| 1–2 years | 5329 (10.6) | 123 (14.0) | 256 (8.2) | 3218 (6.4) | 122 (18.2) | 930 (8.6) | 67 (17.7) |
| 2–3 years | 4792 (9.5) | 105 (11.9) | 246 (7.9) | 3157 (6.3) | 89 (13.7) | 783 (7.5) | 43 (11.5) |
| 3–4 years | 4353 (8.6) | 99 (11.3) | 234 (7.5) | 2937 (5.8) | 78 (12.6) | 677 (6.8) | 32 (8.7) |
| 4–5 years | 3685 (8.0) | 63 (8.3) | 225 (7.6) | 2583 (5.6) | 58 (9.7) | 611 (6.5) | 25 (7.1) |
| ≥5 years | 7298 (17.3) | 43 (7.6) | 603 (21.0) | 5983 (14.2) | 111 (19.6) | 1440 (16.4) | 65 (19.1) |
| Use of antidepressants at or before index day | |||||||
| Index day | 11 164 (22.1) | 94 (10.7) | 817 (26.3) | 4981 (9.9) | 228 (34.1) | 2843 (26.3) | 134 (35.4) |
| 1–182 days | 13 165 (26.1) | 129 (14.7) | 922 (29.7) | 6189 (12.3) | 239 (35.7) | 3130 (29.0) | 142 (37.5) |
| 183–365 days | 11 204 (22.2) | 107 (12.2) | 801 (25.8) | 5807 (11.5) | 201 (30.0) | 2832 (26.2) | 127 (33.5) |
| 1–2 years | 11 284 (22.4) | 115 (13.1) | 782 (25.2) | 6417 (12.7) | 209 (31.2) | 2716 (25.2) | 129 (34.0) |
| 2–3 years | 10 014 (19.9) | 107 (12.2) | 667 (21.5) | 5970 (11.8) | 177 (27.2) | 2234 (21.4) | 109 (29.1) |
| 3–4 years | 8912 (17.7) | 87 (9.9) | 618 (19.9) | 5535 (11.0) | 142 (22.9) | 1897 (19.0) | 94 (25.6) |
| 4–5 years | 7420 (16.1) | 70 (9.2) | 524 (17.6) | 4800 (10.4) | 120 (20.1) | 1534 (16.3) | 73 (20.7) |
| ≥5 years | 9565 (22.7) | 43 (7.6) | 809 (28.2) | 7164 (17.0) | 158 (28.0) | 2149 (24.4) | 102 (29.9) |
| Use of anxiolytics at or before index day | |||||||
| Index day | 2265 (4.5) | 24 (2.7) | 123 (4.0) | 1327 (2.6) | 88 (13.2) | 444 (4.1) | 51 (13.5) |
| 1–182 days | 3304 (6.6) | 36 (4.1) | 188 (6.0) | 2075 (4.1) | 116 (17.3) | 668 (6.2) | 67 (17.7) |
| 183–365 days | 2506 (5.0) | 24 (2.7) | 132 (4.2) | 1988 (3.9) | 87 (13.0) | 593 (5.5) | 42 (11.1) |
| 1–2 years | 2901 (5.8) | 41 (4.7) | 159 (5.1) | 2354 (4.7) | 89 (13.3) | 646 (6.0) | 46 (12.1) |
| 2–3 years | 2778 (5.5) | 52 (5.9) | 159 (5.1) | 2356 (4.7) | 75 (11.5) | 541 (5.2) | 46 (12.3) |
| 3–4 years | 2698 (5.4) | 49 (5.6) | 146 (4.7) | 2295 (4.6) | 65 (10.5) | 509 (5.1) | 40 (10.9) |
| 4–5 years | 2448 (5.3) | 44 (5.8) | 146 (4.9) | 2014 (4.4) | 60 (10.1) | 461 (4.9) | 29 (8.2) |
| ≥5 years | 4624 (11.0) | 26 (4.6) | 387 (13.5) | 3904 (9.3) | 108 (19.1) | 1024 (11.6) | 60 (17.6) |
| Use of hypnotics at or before index day | |||||||
| Index day | 4935 (9.8) | 114 (13.0) | 246 (7.9) | 3662 (7.3) | 123 (18.4) | 899 (8.3) | 75 (19.8) |
| 1–182 days | 6287 (12.5) | 137 (15.6) | 317 (10.2) | 4559 (9.0) | 145 (21.7) | 1066 (9.9) | 87 (23.0) |
| 183–365 days | 5267 (10.4) | 115 (13.1) | 275 (8.8) | 4437 (8.8) | 131 (19.6) | 916 (8.5) | 68 (17.9) |
| 1–2 years | 5690 (11.3) | 129 (14.7) | 322 (10.4) | 4913 (9.7) | 128 (19.1) | 980 (9.1) | 64 (16.9) |
| 2–3 years | 5472 (10.8) | 127 (14.4) | 288 (9.3) | 4872 (9.7) | 97 (14.9) | 901 (8.6) | 53 (14.1) |
| 3–4 years | 5266 (10.4) | 128 (14.6) | 293 (9.4) | 4732 (9.4) | 84 (13.6) | 859 (8.6) | 47 (12.8) |
| 4–5 years | 4669 (10.1) | 106 (13.9) | 271 (9.1) | 4198 (9.1) | 66 (11.1) | 777 (8.2) | 37 (10.5) |
| ≥5 years | 6611 (15.7) | 71 (12.5) | 489 (17.1) | 5832 (13.9) | 123 (21.8) | 1296 (14.7) | 70 (20.5) |
*Referrals to psychiatrist, geriatrician or neurologist; index day: day of first diagnosis of dementia in dementia cohort, respective day in the matched control cohort, or day of first use of memantine or an acetylcholinesterase inhibitor (AChEIs).