a Distribution of written score differences for participants who completed the written SDMT in the course of six months. Using the current score decrease of four points, approximately 24% of participants would have been falsely classified as having meaningful decline in their cognitive processing speed. We propose that this threshold should be increased to 13 points, or (average difference) – (1.5 × IQR of the differences). b Comparison of changes in disability scores for individuals who are above or below the defined threshold. At the four-points threshold, there is no significant difference in disability score changes between individuals who are below and above the threshold. At the 13-points threshold, while there is also no significant difference in disability changes between individuals who fall above or below the threshold, the disability changes are much larger in CombiWISE and NeurEx. The lack of statistical significance may be due to the low number of individuals who fall below the 13-points threshold.