Ethnicity and thrombolysis in ischemic stroke: a hospital based study in Amsterdam

BACKGROUND: Ethnic differences have been reported with regard to several medical therapies. The aim of this study was to investigate the relation between ethnicity and thrombolysis in stroke patients. METHODS: Retrospective single-centre study. Patients admitted with an ischemic stroke between 2003 and 2008 were included. Ethnicity was determined by self-identification and stratified into white and non-white (all other ethnicities). The main outcome measure was the difference in thrombolysis rate between white and non-white patients. Logistic regression analysis was used to identify potential confounders of the relation between ethnicity and thrombolysis. RESULTS: 510 patients were included, 392 (77%) white and 118 (23%) non-white. Non-white patients were younger (median 69 vs. 60 years, p < 0.001), had a higher blood pressure at admission (median systolic 150 vs. 160 mmHg, p = 0.02) and a lower stroke severity (median NIHSS 5 vs. 4, p = 0.04). Non-white patients were significantly less often treated with thrombolysis compared to white patients (odds ratio 0.34, 95% CI 0.17-0.71), which was partly explained by a later arrival at the hospital. After adjustment for potential confounders (late arrival, age, blood pressure above upper limit for thrombolysis, and oral anticoagulation use), a trend towards a lower thrombolysis rate in non-whites remained (adjusted odds ratio 0.38, 95% CI 0.13 to 1.16). CONCLUSIONS: Non-white stroke patients less often received thrombolysis than white patients, partly as a result of a delay in presentation. In this single centre study, potential bias due to hospital differences or insurance status could be ruled out as a cause. The magnitude of the difference is worrisome and requires further investigation. Modifiable causes, such as patient delay, awareness of stroke symptoms, language barriers and treatment of cardiovascular risk factors, should be addressed specifically in these ethnic groups in future stroke campaigns.