Table 2. Primary and Secondary Outcomes.
| Outcomes and unadjusted associations, No. (%) of patients | Absolute difference (95% CI) | MSU dispatch vs conventional ambulancea | |||
|---|---|---|---|---|---|
| MSU dispatch (n = 749) | Conventional ambulance (n = 794) | Adjusted common OR (95% CI) | P value | ||
| Primary outcomes at 3 months | |||||
| No. | 654 | 683 | |||
| mRS score, median (IQR) | 1 (0-3) | 2.0 (0-3) | −1 (−3 to −0.5)b | 0.71 (0.58 to 0.86)c | <.001 |
| Coprimary efficacy outcomes at 3 months,d | |||||
| No. | 730 | 776 | |||
| mRS 0-3 or living at home | 586 (80.3) | 605 (78.0) | 2.3 (−1.8 to 6.4) | 0.73 (0.54 to 0.99)c | .04 |
| mRS 4-5 or living in nursing care institution | 92 (12.6) | 103 (13.3) | −0.7 (−4.1 to 2.7) | ||
| Death | 52 (7.1) | 68 (8.8) | −1.7 (−4.4 to 1.1) | ||
| Secondary outcomes | |||||
| No. | 748 | 794 | |||
| tPA | 451 (60.2) | 382 (48.1) | 12.1 (7.2 to 17.0) | 1.62 (1.32 to 2.00) | <.001 |
| Endovascular treatments | 103 (13.8) | 103 (13.0) | 0.8 (−2.6 to 4.2) | 0.80 (0.58 to 1.10) | .17 |
| No. | 716 | 787 | |||
| Dispatch to imaging, median (IQR), min | 45 (32 to 75) | 60 (49 to 77) | −15 (−18 to −12) | Mean difference, −20 (−26 to −15)e | <.001 |
| Selected short-term outcomes | |||||
| No. | 749 | 794 | |||
| Discharge | |||||
| Home | 453 (60.5) | 445 (56.0) | 4.5 (−0.5 to 9.4) | 1.42 (1.12 to 1.81) | .004 |
| Rehabilitation | 157 (21.0) | 151 (19.0) | 2.0 (−2.0 to 5.9) | 0.91 (0.69 to 1.19) | .49 |
| Nursing care home | 49 (6.5) | 60 (7.6) | −1.1 (−3.6 to 1.5) | 1.05 (0.57 to 1.93) | .87 |
| Inhospital death | 19 (2.5) | 30 (3.8) | −1.3 (−3.0 to 0.5) | 0.61 (0.33 to 1.12) | .11 |
| Symptomatic secondary intracranial hemorrhage | 24 (3.2) | 22 (2.8) | 0.4 (−1.3 to 2.1) | 1.20 (0.66 to 2.19) | .56 |
| 7-Day mortality | 13 (1.7) | 24 (3.0) | −1.3 (−2.8 to 0.2) | 0.54 (0.26 to 1.12) | .10 |
| mRS scoref | |||||
| No. | 654 | 683 | |||
| 0 | 199 (30.4) | 171 (25.0) | 5.4 (0.6 to 10.2) | 0.71 (0.58 to 0.86)a | <.001 |
| 1 | 134 (20.5) | 118 (17.3) | 3.2 (−1.0 to 7.4) | ||
| 2 | 79 (12.1) | 99 (14.5) | −2.4 (−6.0 to 1.2) | ||
| 3 | 114 (17.4) | 133 (19.5) | −2.1 (−6.2 to 2.1) | ||
| 4 | 76 (11.6) | 94 (13.8) | −2.2 (−5.7 to 1.4) | ||
| ≥5 | 52 (8.0) | 68 (10.0) | −2.0 (−5.1 to 1.1) | ||
| 3-Month outcomes | |||||
| No. | 635 | 669 | |||
| Unfavorableg | 295 (46.5) | 359 (53.7) | −7.2 (−12.6 to −1.8) | 0.70 (0.56 to 0.87) | .002 |
| Quality of life, mean (SD) | |||||
| No. | 605 | 631 | |||
| EQ-5D visual analog scaleh | 60 (29) | 55 (29) | 5 (2 to 8) | Mean difference, 4.3 (1.5 to 7.2) | .003 |
| No. | 618 | 649 | |||
| EQ-5D total scorei | 63 (34) | 59 (35) | 4 (0.3 to 8) | Mean difference, 4.4 (1.2 to 7.7) | .007 |
| Sensitivity analysis of patients with documentation of neurological deficits (MSU dispatch, n = 668; conventional ambulance, n = 638) | |||||
| No. | 584 | 550 | |||
| mRS score, median (IQR)j | 2 (0 to 3) | 2 (1 to 4) | 0 (−0.3 to 0.3) | 0.73 (0.59 to 0.91)b | .005 |
| Times to tPA, median (IQR), min | |||||
| No. | 421 | 371 | |||
| Imaging to tPA | 12 (7 to 22) | 15 (10 to 23) | −3(−5 to −1) | Mean difference, −0.1 (−0.2 to 0.03)e | .17 |
| No. | 448 | 377 | |||
| Onset or last-seen-well to tPA | 95 (60 to 149) | 110 (80 to 165) | −15 (−27 to −3) | Mean difference, −13 (−21 to −4) | .003 |
| No. | 448 | 377 | |||
| Mean (SD) | 112 (62) | 126 (61) | |||
| No. | 449 | 380 | |||
| Dispatch to tPA | 50 (43 to 64) | 70 (59 to 86) | −20 (−23 to −17) | Mean difference, −26 (−31 to −22)e | <.001 |
Abbreviations: EQ-5D, European Quality of Life 5 Dimensions; IQR, interquartile range; mRS, modified Rankin Scale; MSU, mobile stroke unit; OR, odds ratio; tPA, tissue plasminogen activator.
Adjusted for age, sex, hypertension, diabetes, living situation, documentation of deficits at MSU arrival, atrial fibrillation, and center heterogeneity (by including random intercepts). Multiple imputation was performed with 10 imputed data sets.
Derived from quantile regression.
Common ORs for ordinal outcomes are based on partial proportional odds models using the proportional odds model only for variables for which the assumptions for the model were met and multinomial model parameters otherwise. Odds ratios for binary outcomes are based on binary logistic regression models; adjusted mean differences, on linear regression models. All models were adjusted for center heterogeneity by including random intercepts for the centers. Common ORs less than 1.00 indicate a favorable shift in the outcome distribution, reducing odds of higher levels of disability.
See the Methods section for coprimary outcome definitions.
Log-transformed values. Mean differences (95% CIs) are presented as percentages.
mRS scores were analyzed across 6 levels of 0, 1, 2, 3, with 4 and 5 collapsed, and 6.
Defined as mRS 2 to 6 in patients 80 years or younger and mRS of 3 to 6 in patients older than 80 years or living at home with help or living in a nursing facility before stroke.
A measure of generic health status, ranging from 0 (the worst health you can imagine) to 100 (the best health you can imagine).
EQ-5D score, ranges from 0 to 100, is a descriptive measure of mobility, self-care, usual activities, pain or discomfort and anxiety or depression with each of the 3 levels: no problems, some problems, and extreme problems the most appropriate statement in each of the five dimensions results in a 1-digit number.
Analysis restricted to patients with documented neurological deficits at EMS arrival.