Effects of emergency medical services on timely treatment and outcome in stroke patients with intravenous thrombolysis among the severity of neurologic deficits: A retrospective observational study

Whether emergency medical service (EMS) improves the outcome of acute ischemic stroke (AIS) patients after intravenous thrombolysis (IVT) is still unknown among the severity of neurologic deficits. This study is to investigate the impact of EMS use on timely treatment and outcomes of AIS with IVT. This is a retrospective observational study. Clinical data after IVT from January 2017 to May 2020 were retrospectively analyzed, including onset-to-needle time (ONT), onset-to-door time (ODT). The patients were divided into EMS and non-EMS groups according to the method of admission. A good outcome was defined as a modified Rankin scale score of ≤2 at 3 months. The severity of neurological deficits was assessed using the national institutes of health stroke scale. A total of 2303 patients were analyzed (906 [(39.3%] female; mean age, 68 ± 13 year), and 1028 (44.6%) patients were transported by EMS and 1418 (67.9%) patients achieved good outcome. Among all patients, compared with non-EMS patients, EMS patients had shorter ONT (148 minutes vs 155 minutes, P = .002) and ODT (95 minutes vs 104 minutes, P < .001), but lower rate of good outcome (61.7% vs 73.0%, P < .001). The multivariate analysis showed that the use of EMS was negatively associated with ONT (ρ = −0.041, P = .048) and ODT (ρ = −0.051, P = .014). Among moderate to severe stroke patients, EMS was related with good outcome independently (OR: 3.101, 95%CI: 1.367–7.038, P = .007). In ischemic stroke, EMS can shorten the pre-hospital delay. Among moderate to severe stroke patients, EMS can further improve the outcome. But the study needs further validation.