Effect of emergency medical services (EMS) utilization on pretreatment time, rate of thrombolytic therapy and 3-month clinical outcomes in acute ischemic stroke patients

Abstract

This prospective cohort study aimed to determine the effect of emergency medical services (EMS) utilization on pretreatment time, rate of thrombolytic therapy and 3-month clinical outcomes in acute ischemic stroke patients. Two hundred and eighty patients who had their first acute ischemic stroke within 24 hours were enrolled from 3 tertiary-care hospitals in Bangkok. Utilization of EMS, demographic and clinical data were obtained from interviews with patients and/or caregivers, and a review of medical records. Clinical outcome at 3 months was obtained from telephone interviews with patients and/or caregivers and was classified as favorable if the modified Rankin Scale (mRS) result was 0 - 2, and unfavorable otherwise. Multiple logistic regression analysis was used to determine the association between EMS utilization and clinical outcome. At 3 months, 43.6% of patients utilizing EMS had a favorable clinical outcome as compared to 53.0% in patients not using EMS [adjusted odds ratio (OR) 0.76, 95% confidence interval (CI) 0.33 to 1.79, p = 0.53]. The effect of EMS utilization on clinical outcomes differed significantly between patients with and without a history of hypertension (with hypertension, adjusted OR 0.14, 95% CI 0.03 to 0.82, p = 0.029; without hypertension, adjusted OR 4.56, 95% CI 0.92 to 22.55, p = 0.063; p for interaction = 0.038). Utilization of EMS, as compared to not using EMS, significantly decreased transportation time (42 versus 60 minutes, p = 0.001), waiting time (5 versus 10 minutes, p < 0.001) and significantly increased the rate of r-tPA therapy (30.0% versus 10.4%, p = 0.001).