Development of a Conversion Factor to Facilitate Comparison of National Institute of Health Stroke Scale Scores with Scandinavian Stroke Scale Scores

A total of 144 patients were included (46% males, mean age = 73 years). At presentation the median SSS score was 38 (2-58), and a week later 40 (4-58), the median NIHSS score at presentation was 5 (0-29) and a week later 3 (0-27). Changes in both scales were strongly correlated, r = 0.76, p < 0.001. Both were good predictors of mortality. Linear regression analysis produced an equation relating the two: SSS = 50 - 2 x NIHSS.