Clinical characteristics of the included patients
| Variable | Phase 1 26 months | Phase 2 13 months | Phase 3 17 months | Phase 4 16 months | P value |
| n=26 | n=30 | n=68 | n=56 | ||
| Female sex, n (%) | 11 (42) | 12 (40) | 25 (37) | 23 (41) | 0.948 |
| Age, years, median (IQR) | 78 (68–85) | 76 (67–83) | 76 (69–84) | 75 (69–82) | 0.856 |
| EMS pre-notification, n (%) | 18 (69) | 27 (90) | 57 (84) | 43 (77) | 0.186 |
| Arrival in daytime on weekdays, n (%) | 13 (50) | 10 (33) | 29 (43) | 16 (29) | 0.203 |
| NIHSS score on admission, median (IQR) | 22 (16–29) | 17 (11–22) | 17 (8–20) | 15 (10–23) | 0.016 |
| Onset-to-reperfusion time, min, median (IQR) | 310 (230–807) | 225 (166–332) | 218 (156–383) | 235 (164–524) | 0.032 |
| Onset-to-door time, min, median (IQR) | 95 (40–482) | 82 (53–282) | 80 (48–253) | 106 (49–419) | 0.673 |
| Door-to-reperfusion time, min, median (IQR) | 199 (172–244) | 135 (108–168) | 129 (99–165) | 121 (94–157) | <0.001 |
| Door-to-imaging time, min, median (IQR) | 31 (22–39) | 23 (20–28) | 27 (21–33) | 23 (19–32) | 0.062 |
| Imaging-to-puncture time, min, median (IQR) | 95 (84–119) | 57 (42–79) | 49 (38–71) | 50 (38–79) | <0.001 |
| Puncture-to-reperfusion time, min, median (IQR) | 68 (44–107) | 52 (28–72) | 41 (27–70) | 38 (22–59) | 0.003 |
| Door-to-reperfusion time <90 min, n (%) | 0 (0) | 2 (7) | 11(16) | 10 (18) | 0.078 |
| Door-to-reperfusion time <120 min, n (%) | 1 (4) | 11 (37) | 33 (49) | 28 (50) | <0.001 |
| Using stent retrievers, n (%) | 1 (4) | 5 (17) | 19 (28) | 28 (50) | <0.001 |
| Successful reperfusion*, n (%) | 20 (77) | 25 (83) | 57 (84) | 44 (79) | 0.812 |
| MRI-first, n (%) | 2 (8) | 16 (53) | 52 (77) | 46 (82) | <0.001 |
| Major artery occlusion† on admission, n (%) | 24 (92) | 20 (67) | 45 (66) | 27 (48) | 0.002 |
| Concomitant t-PA treatment, n (%) | 12 (46) | 17 (57) | 22 (32) | 19 (34) | 0.095 |
| Door-to-needle time, min, median (IQR)‡ | 80 (74–119) | 66 (53–76) | 63 (57–86) | 60 (55–76) | 0.069 |
| Symptomatic intracerebral hemorrhage, n (%) | 3 (11.5) | 2 (6.7) | 4 (5.9) | 2 (3.6) | 0.575 |
| Cardioembolic stroke on TOAST criteria, n (%) | 24 (92) | 20 (67) | 44 (65) | 33 (59) | 0.025 |
| mRS score 0–2 at 3 months after stroke, n (%) | 12 (46) | 16 (53) | 29 (43) | 23 (41) | 0.720 |
Phase 1: From January 2013 to February 2015.
Phase 2: From March 2015 to March 2016.
Phase 3: From April 2016 to August 2017.
Phase 4: From September 2017 to December 2018.
*Defined as Thrombolysis in Cerebral Infarction score 2b or 3.
†Internal carotid artery, middle cerebral artery horizontal segment, and basilar artery occlusion.
‡For only patients treated with intravenous tissue-plasminogen activator.
EMS, emergency medical service; MRI, magnetic resonance imaging; mRS, modified Rankin Scale; NIHSS, National Institutes of Health Stroke Scale; TOAST, Trial of ORG 10172 in Acute Stroke Treatment; t-PA, tissue plasminogen activator.