Characteristics of the included studies
| Study | Design | Setting | Sample size | Follow-up duration (months) | Baseline NIHSS (IQR): ENI achieved | Baseline NIHSS (IQR): ENI not achieved | Mean (SD) age, years: ENI achieved | Mean (SD) age, years: ENI not achieved | Median (IQR) age, years: ENI achieved | Median (IQR) age, years: ENI not achieved | Male (%): ENI achieved | Male (%): ENI not achieved | HTN (%): ENI achieved | HTN (%): ENI not achieved | DM (%): ENI achieved | DM (%): ENI not achieved | Smoking (%): ENI achieved | Smoking (%): ENI not achieved | CAD (%): ENI achieved | CAD (%): ENI not achieved |
| Weyland18 | Retrospective | Single center | 549 | 3 | 15 (1–41) | 18 (0–38) | 75 (28–99) | 67.5 (49–91) | 47 | 59 | 81 | 77 | 22 | 31 | 14 | 14 | 27 | 35 | ||
| Guenego14 | Retrospective | Multicenter | 237 | 3 | 15 (9–23) | 17 (9–39) | 68 (53–78) | 64 (55–76) | 53 | 64 | 53 | 60 | 16 | 25 | 19 | 26 | ||||
| Sun15 | Prospective | Single center | 187 | 3 | 28 (16–34) | 17 (9–34) | 60 (11) | 59 (10) | 75.8 | 88 | 66.1 | 73.6 | 22.6 | 29.6 | 12.9 | 10.4 | ||||
| Wirtz*16 | Retrospective | Single center | 155 | 3 | 18 (14–24) | 71.5 (61–82) | 48.1 | 76.7 | 26.4 | 25.2 | ||||||||||
| Heit13 | Prospective | Multicenter | 91 | 3 | 17 (13–21) | 15.5 (9.5–20) | 68 (61–76) | 71 (59–81) | 48 | 52 | 74 | 80 | 26 | 33 | ||||||
| Soize19 | Retrospective | Single center | 244 | 3 | 17 (14–21) | 19 (14–23) | 65.5 (51.5–76) | 69.0 (58.5–78) | 44.5 | 53.4 | 44.5 | 44.1 | 11.8 | 16.1 | 28.3 | 22.5 | ||||
| Pu20 | Retrospective | Multicenter | 568 | 3 | 16 (11–19) | 16 (12–21) | 64 (54–72) | 65 (55–73) | 63.7 | 61.3 | 60.6 | 65.5 | 17.3 | 19.7 | 28.9 | 26.4 | 20.5 | 24.6 | ||
| Cao21 | Retrospective | Multicenter | 97 | 3 | 14 (11–17) | 17 (12–20) | 60.8 (9.2) | 62.9 (10.7) | 71.4 | 56.4 | 66.7 | 61.8 | 23.8 | 16.4 | 40.5 | 29.1 | ||||
| Cai17 | Prospective | Multicenter | 227 | 3 | 15.5 (10.5–20.5) | 14 (7–21) | 62.86 (13.93) | 67.65 (11.64) | 60 | 56 | 56 | 57 | 10 | 14 | 16 | 24 | 12 | 19 |
*Wirtz et al did not stratify characteristics by ENI status; relevant characteristics for the entire study are listed in the “ENI achieved” column
CAD, coronary artery disease; DM, diabetes mellitus; ENI, early neurological improvement; HTN, hypertension; NIHSS, National Institutes of Health Stroke Scale.