Stroke severity, its correlates and impact on thrombolysis in a population-based study

Data about the distribution of stroke severity and its correlates are sparse. In a population-based approach, we determined the NIH Stroke Scale Score (NIHSSS) and studied associations with demographic variables, stroke unit care, etiology, the onset assessment interval (OAI), and the rate of thrombolysis.

We performed a databank-based post-hoc analysis of data ascertained during the prospective, population-based stroke study among the 188,015 permanent residents of Basel City, Switzerland.

In 246/269 (91.4%) patients, NIHSSS was available. The median NIHSSS was 5.0 +/- 6.0. NIHSSS 0-6, 7-15, and >15 were present in 156 (63%), 56 (23%), and 34 (14%) patients. Higher NIHSSS were associated with advancing age (p = 0.038), female gender (p = 0.04), stroke unit treatment (p = 0.003), cardioembolism (p < 0.001), shorter OAI (p = 0.009), and thrombolytic therapy (p < 0.001). In multivariate regression analyses, age, OAI, and thrombolysis correlated independently with higher NIHSSS. Stroke unit patients differed from non-stroke unit patients in shorter OAI, younger age, and higher NIHSSS.

In a geographically defined stroke population, 1/3 patients had moderate-to-severe stroke. Patients with less severe strokes were younger, sought medical attention later and were less likely to receive thrombolysis. Thus, public stroke awareness programs might consider targeting also younger individuals and stress that also mild-to-moderate strokes benefit from emergency medical care.