Table 1. Baseline personal characteristics of patients with dementia and non-dementia controls (n=975 127).
| Characteristics* | Patients (n=170 742) | Controls (n=804 385) |
|---|---|---|
| Mean (SD) age (years) at diagnosis or index date | 82.3 (7.7) | 81.8 (7.6) |
| Median (IQR) age (years) at diagnosis or index date | 83 (78-88) | 83 (77-87) |
| Age (years) at diagnosis or index date: | ||
| 55-64 | 4309 (2.5) | 21 524 (2.7) |
| 65-74 | 21 649 (12.7) | 107 702 (13.4) |
| 75-84 | 72 521 (42.5) | 355 477 (44.2) |
| 85-94 | 66 493 (38.9) | 300 824 (37.4) |
| ≥95 | 5770 (3.4) | 18 858 (2.3) |
| Sex: | ||
| Men | 63 865 (37.4) | 299 348 (37.2) |
| Women | 106 877 (62.6) | 505 037 (62.8) |
| No of patients with ethnic group records†: | 78 071 (100) | 348,316 (100) |
| White | 74 641 (95.6) | 330 750 (95.0) |
| Bangladeshi | 44 (0.06) | 149 (0.04) |
| Black African | 105 (0.13) | 383 (0.11) |
| Black Caribbean | 428 (0.55) | 1366 (0.39) |
| Black other | 69 (0.09) | 227 (0.07) |
| Chinese | 61 (0.08) | 381 (0.11) |
| Indian | 408 (0.52) | 2022 (0.58) |
| Mixed | 127 (0.16) | 546 (0.16) |
| Other Asian | 132 (0.17) | 718 (0.21) |
| Pakistani | 157 (0.20) | 753 (0.22) |
| Other | 1899 (2.43) | 11 021 (3.17) |
| Index of multiple deprivation (group): | ||
| 1 (least deprived) | 18 294 (10.7) | 91 237 (11.3) |
| 2 | 17 195 (10.1) | 85 780 (10.7) |
| 3 | 18 068 (10.6) | 80 994 (10.1) |
| 4 | 13 220 (7.7) | 59 933 (7.5) |
| 5 (most deprived) | 12 290 (7.2) | 50 153 (6.2) |
| Missing index of multiple deprivation records | 91 675 (53.7) | 436 288 (54.2) |
| Body mass index: | ||
| Mean (SD) body mass index | 25.7 (4.5) | 26.5 (4.7) |
| Missing body mass index records | 42 634 (25.0) | 133 308 (16.6) |
| Smoking status (most recent before index date): | ||
| Non-smoker | 80 020 (46.9) | 414 421 (51.5) |
| Ex-smoker | 47 783 (28.0) | 244 276 (30.4) |
| Current smoker | 13 247 (7.8) | 61 262 (7.6) |
| Missing smoking records | 29 692 (17.4) | 84 426 (10.5) |
| Alcohol status (most recent before index date): | ||
| Non-alcohol drinker | 39 280 (23.0) | 176 261 (21.9) |
| Ex-alcohol drinker | 6775 (4.0) | 24 230 (3.0) |
| Alcohol drinker | 81 414 (47.7) | 464 751 (57.8) |
| Missing alcohol records | 43 273 (25.3) | 139 143 (17.3) |
Data are number (%) unless indicated otherwise.
*
Baseline characteristics measured at index date.
†
Records of ethnic group were available for 426 387 (42.4%) individuals in the study who were eligible for linkage with Hospital Episodes Statistics. Therefore, records were missing for 92 671 (54.3%) patients and 456 069 (56.7%) controls.
IQR, interquartile range; SD, standard deviation.