Table 1.
Baseline characteristics of cases of ischaemic stroke and matched controls*. Values are numbers (percentages) unless stated otherwise
| Characteristics | Cases (n=1477) | Controls (n=7349) | Standardised difference† |
|---|---|---|---|
| Demographics | |||
| Mean (95% CI) age at index date | 81.8 (81.4 to 82.2) | 81.8 (81.7 to 82.0) | 0 |
| Male sex | 591 (40.0) | 2946 (40.1) | 0 |
| Fifth of income: | |||
| Missing | ≤5 (0.1) | 31 (0.4) | 0.05 |
| 1 | 314 (21.3) | 1420 (19.3) | 0.05 |
| 2 | 341 (23.1) | 1530 (20.8) | 0.05 |
| 3 | 297 (20.1) | 1516 (20.6) | 0.01 |
| 4 | 276 (18.7) | 1418 (19.3) | 0.01 |
| 5 | 247 (16.7) | 1434 (19.5) | 0.01 |
| Rural residence | 238 (16.1) | 1027 (14.0) | 0.06 |
| Comorbidities | |||
| Mean (SD) No of unique drugs prescribed in previous year | 14.2 (8.1) | 12.2 (7.5) | 0.25 |
| Atrial fibrillation | 674 (45.6) | 1986 (27.0) | 0.41 |
| Coronary artery bypass grafting surgery | 37 (2.5) | 143 (1.9) | 0.04 |
| Cancer | 120 (8.1) | 414 (5.6) | 0.1 |
| Chronic renal insufficiency | 129 (8.7) | 283 (3.9) | 0.23 |
| Diabetes | 633 (42.9) | 3141 (42.7) | 0 |
| Drugs used in previous year | |||
| Angiotensin converting enzyme inhibitors | 712 (48.2) | 2911 (39.6) | 0.18 |
| Angiotensin receptor blockers | 386 (26.1) | 1731 (23.6) | 0.06 |
| Hydroxymethyl glutaryl coenzyme A reductase inhibitors (statins) | 825 (55.9) | 3645 (49.6) | 0.13 |
| Clopidogrel | 212 (14.4) | 541 (7.4) | 0.25 |
| Warfarin | 346 (23.4) | 962 (13.1) | 0.29 |
| Acetylsalicylic acid/dipyridamole | 118 (8.0) | 157 (2.1) | 0.34 |
| Hormone replacement therapy | 19 (1.3) | 71 (1.0) | 0.03 |
| Low molecular weight heparin | 24 (1.6) | 69 (0.9) | 0.07 |
| Diuretics | 781 (52.9) | 3383 (46.0) | 0.14 |
| Diuretics, potassium sparing | 116 (7.9) | 509 (6.9) | 0.04 |
| Calcium channel blocker | 652 (44.1) | 2825 (38.4) | 0.12 |
| History of outcome | |||
| Ischaemic stroke | 64 (4.3) | 284 (3.9) | 0.02 |
All cells with values of 5 or less are reported as ≤5 for privacy reasons.
*Up to 5 controls were matched to each case on age (±1 year), sex, diabetes, and history of outcome.
†Difference between cases and controls divided by pooled standard deviation of two groups; standardised differences <0.1 indicate good balance between groups.