Demographics and clinical characteristics by seasonal period
| Baseline characteristics | Total (n=1364) | March–July 2019 (n=794) | March–July 2020 (n=570) | P-value |
| Age group, no. (%) | 0.47 | |||
| <50 | 151 (11%) | 93 (12%) | 58 (10%) | |
| 50–69 | 524 (38%) | 310 (39%) | 214 (38%) | |
| ≥70 | 689 (51%) | 391 (49%) | 298 (52%) | |
| Female, no. (%) | 649 (48%) | 382 (48%) | 267 (47%) | 0.64 |
| Hispanic, no. (%) | 199/1,349 (15%) | 102/786 (13%) | 97/563 (17%) | 0.03 |
| Race, no. (%) | 0.07 | |||
| White | 827 (61%) | 460 (58%) | 367 (64%) | |
| Black | 329 (24%) | 198 (25%) | 131 (23%) | |
| Asian | 29 (2%) | 19 (2%) | 10 (2%) | |
| Other/unknown | 179 (13%) | 117 (15%) | 62 (11%) | |
| Medical history, no. (%) | ||||
| Hypertension | 1021 (75%) | 600 (76%) | 421 (74%) | 0.47 |
| Dyslipidemia | 637 (47%) | 359 (45%) | 278 (49%) | 0.19 |
| Diabetes | 437 (32%) | 245 (31%) | 192 (34%) | 0.27 |
| Atrial fibrillation | 297 (22%) | 174 (22%) | 123 (22%) | 0.88 |
| Tobacco use | 256 (19%) | 153 (19%) | 103 (18%) | 0.58 |
| Prior ischemic stroke | 248 (18%) | 135 (17%) | 113 (20%) | 0.18 |
| Coronary artery disease | 204 (15%) | 91 (11%) | 113 (20%) | <0.01 |
| Arrival method, no. (%) | 0.42 | |||
| EMS | 416/1,245 (33%) | 222/696 (32%) | 194/549 (35%) | |
| Walk-in/private vehicle | 85/1,245 (7%) | 50/696 (7%) | 35/549 (6%) | |
| Transfer | 744/1,245 (60%) | 424/696 (61%) | 320/549 (58%) | |
| NIHSS on arrival, median (IQR) | 14 (7–21) (n=1035) | 14 (6–20) (n=596) | 15 (7–21) (n=439) | 0.16 |
| Intravenous thrombolysis, no. (%) | 180/1,124 (16%) | 93/655 (14%) | 87 (19%) | 0.05 |
| Site of occlusion, no. (%) | ||||
| ICA | 327 (24%) | 189 (24%) | 138 (24%) | 0.86 |
| MCA–M1 | 659 (48%) | 381 (48%) | 278 (49%) | 0.77 |
| MCA–M2 | 317 (23%) | 190 (24%) | 127 (22%) | 0.48 |
| MCA–M3 | 68 (5%) | 44 (6%) | 24 (4%) | 0.27 |
| Basilar artery | 86 (6%) | 42 (5%) | 44 (8%) | 0.07 |
| Vertebral artery | 55 (4%) | 34 (4%) | 21 (4%) | 0.58 |
| Thrombectomy, no. (%) | 1003 (74%) | 563 (71%) | 440 (77%) | <0.01 |
| Thrombectomy for ICA, M1, or basilar occlusions, no. (%) | 789/1,003 (79%) | 430/569 (76%) | 359/434 (83%) | <0.01 |
EMS, emergency medical services; ICA, internal carotid artery; IQR, interquartile range; MCA, middle cerebral artery; NIHSS, National Institutes of Health Stroke Scale score.