Table 1.
Baseline characteristics of young and old patients with ischaemic stroke
| Baseline characteristics | Total (n=793 175 (100%)) |
Young adults (<50 years) (n=71 860 (9.1%)) |
Old adults (≥50 years) (n=721 315 (90.9%)) |
ASD (%)/H-L estimator* |
| Patient characteristics | ||||
| Age, years | 66.1±12.0 | 43.8±5.3 | 68.3±10.0 | 306.1 |
| Male, n (%) | 496 960 (62.7) | 54 850 (76.3) | 442 110 (61.3) | 32.8 |
| Insurance status, n (%) | ||||
| UEBMI | 225 940 (28.5) | 19 160 (26.7) | 206 780 (28.7) | 4.5 |
| URBMI | 149 839 (18.9) | 12 393 (17.2) | 137 446 (19.1) | 4.9 |
| NRCMS | 333 979 (42.1) | 27 587 (38.4) | 306 392 (42.5) | 8.4 |
| Self-pay | 50 727 (6.4) | 9263 (12.9) | 41 464 (5.7) | 25.0 |
| Other | 32 690 (4.1) | 3457 (4.8) | 29 233 (4.1) | 3.4 |
| Arrive mode, n (%) | ||||
| Ambulance | 89 484 (11.3) | 7170 (10.0) | 82 314 (11.4) | 4.5 |
| Private car | 372 727 (47.0) | 33 340 (46.4) | 339 387 (47.1) | 1.4 |
| Taxi | 68 801 (8.7) | 6743 (9.4) | 62 058 (8.6) | 2.8 |
| Bicycle or tricycle | 7237 (0.9) | 577 (0.8) | 6660 (0.9) | 1.1 |
| Helicopter | 338 (0.0) | 27 (0.0) | 311 (0.0) | |
| Mobile stroke unit | 246 (0.0) | 24 (0.0) | 222 (0.0) | |
| Other | 254 342 (32.1) | 23 979 (33.4) | 230 363 (31.9) | 3.2 |
| Medical history, n (%) | ||||
| Previous stroke/TIA | 261 760 (33.0) | 16 197 (22.5) | 245 563 (34.0) | 25.8 |
| CAD/prior MI | 69 810 (8.8) | 2906 (4.0) | 66 904 (9.3) | 21.4 |
| Diabetes | 170 638 (21.5) | 10 985 (15.3) | 159 653 (22.1) | 17.5 |
| Peripheral vascular disease | 13 512 (1.7) | 718 (1.0) | 12 794 (1.8) | 6.8 |
| Hypertension | 510 928 (64.4) | 38 722 (53.9) | 472 206 (65.5) | 23.8 |
| Smoking† | 294 708 (37.2) | 35 848 (49.9) | 258 860 (35.9) | 28.6 |
| Atrial fibrillation/flutter | 40 231 (5.1) | 886 (1.2) | 39 345 (5.5) | 24.1 |
| Dyslipidaemia | 60 605 (7.6) | 5861 (8.2) | 54 744 (7.6) | 2.2 |
| Carotid stenosis | 10 161 (1.3) | 509 (0.7) | 9652 (1.3) | 6.0 |
| Medication history, n (%) | ||||
| Anticoagulants | 31 326 (3.9) | 2394 (3.3) | 28 932 (4.0) | 3.7 |
| Hypoglycaemic drugs | 133 244 (16.8) | 7802 (10.9) | 125 442 (17.4) | 18.7 |
| Antihypertensive drugs | 370 017 (46.7) | 24 065 (33.5) | 345 952 (48.0) | 29.8 |
| Antiplatelet drugs | 165 771 (20.9) | 10 482 (14.6) | 155 289 (21.5) | 18.0 |
| Lipid-lowering drugs | 118 827 (15.0) | 8171 (11.4) | 110 656 (15.3) | 11.5 |
| NIHSS score in hospital‡ | 3.0 (2.0–6.0) | 3.0 (1.0–5.0) | 3.0 (2.0–6.0) | |
| Biochemical indicators | ||||
| Glycated haemoglobin§, % | 5.8 (5.3–6.5) | 5.7 (5.2–6.1) | 5.8 (5.3–6.5) | |
| BMI¶ | 24.0±4.3 | 24.9±4.8 | 23.9±4.2 | 22.2 |
| Homocysteine**, µmol/L | 13.9 (10.4–19.1) | 13.4 (10.0–19.0) | 13.9 (10.5–19.1) | |
| Systolic blood pressure††, mm Hg | 150.0±23.0 | 147.9±24.4 | 150.2±22.8 | 9.7 |
| Diastolic blood pressure‡‡, mm Hg | 87.0±13.9 | 92.3±16.1 | 86.5±13.5 | 39.0 |
| Hospital characteristics, n (%) | ||||
| Hospital level | ||||
| Secondary hospital | 303 790 (38.3) | 23 993 (33.4) | 279 797 (38.8) | 11.3 |
| Tertiary hospital | 489 385 (61.7) | 47 867 (66.6) | 441 518 (61.2) | 11.3 |
| Hospital region | ||||
| Eastern China | 365 579 (46.1) | 32 744 (45.6) | 332 835 (46.1) | 1.0 |
| Central China | 262 618 (33.1) | 24 477 (34.1) | 238 141 (33.0) | 2.3 |
| Western China | 164 978 (20.8) | 14 639 (20.4) | 150 339 (20.8) | 1.0 |
*H-L estimator; an absolute standardised difference (%) >10% indicates meaningful imbalance between two groups.
†Smoking: having smoking experience or behaviours.
‡Information was missing for n=154 052 patients (19.4%).
§Information was missing for n=84 393 patients (10.6%); median was used for imputation.
¶Information was missing for n=12 698 patients (1.6%); median was used for imputation.
**Information was missing for n=35 781 patients (4.5%).
††Information was missing for n=245 patients (≈0.0%); median was used for imputation.
‡‡Information was missing for n=251 patients (≈0.0%); median was used for imputation.
ASD, absolute standardised difference; CAD, coronary artery disease; H-L, Hodges-Lehmann; MI, myocardial infarction; NIHSS, National Institutes of Health Stroke Scale; NRCMS, New Rural Cooperative Medical Scheme; TIA, transient ischaemic attack; UEBMI, Urban Employee Basic Medical Insurance; URBMI, Urban Resident Basic Medical Insurance.