Introduction: In the last decade, the stroke mortality rate in Poland significantly decreased. We hypothesised that stroke severity, the major determinant of outcome, is lowered in Polish stroke patients.
Material and methods: We compared the stroke severity in two cohorts of first-ever ischaemic stroke patients admitted within 24 h after stroke onset to the Department of Neurology, Jagiellonian University, Krakow in the years 1994–2000 and 2008–2012. To assess stroke severity we used the National Institute of Health Stroke Scale (NIHSS). We defined mild stroke as an NIHSS score  4.
Results: We included 816 patients hospitalised in the years 1994–2000 and 569 patients hospitalised in the years 2008–2012. NIHSS score on admission was higher in the former (mean: 12.0 7.0 vs. 8.0 6.0, p < 0.01), and the frequency of mild stroke was higher in the latter (12.7% vs. 41.8%, p < 0.01). Although the frequency of hypertension (67.3% vs. 81.2%, p < 0.01), diabetes mellitus (20.8% vs. 26.4%, p = 0.02) and atrial fibrillation (20.7% vs. 26.2%, p = 0.02) was higher in patients hospitalised in the years 2008–2012, the systolic and diastolic blood pressure values and the frequency of fasting hyperglycaemia were lower in this cohort. This cohort also less frequently suffered from hypercholesterolaemia (25.4% vs. 16.3%, p < 0.01).
Conclusions: Reduced stroke severity is associated with better recognition and control of risk factors and explains the improvement of survival in Polish stroke patients.