Complex sentence: Many additions and changes to the measure have been made over time, including the addition of dozens of supplemental, validity, and other content scales to improve interpretability of the original Clinical Scales, changes in the number of items in the measure, and other adjustments.
Split into simpler sentences: Many additions and changes to the measure have been made over time to improve interpretability of the original Clinical Scales. Additionally, there have been changes in the number of items in the measure, and other adjustments.