Question
Question Posted 04/02/25:
Hello, I have a question regarding the RAVLT_perc_forgetting variable. In the master ADNIMERGE file, I am seeing values ranging from -1650 to 100 for RAVLT_perc_forgetting. Based on a formula of (immediate recall-delayed recall)/immediate recall * 100, I'm a bit confused as to how these negative values were generated. I would like to better comprehend the scoring in this variable for use, but don't understand how the range falls so negatively outside of 0-100. Thank you so much!
Hello, I have a question regarding the RAVLT_perc_forgetting variable. In the master ADNIMERGE file, I am seeing values ranging from -1650 to 100 for RAVLT_perc_forgetting. Based on a formula of (immediate recall-delayed recall)/immediate recall * 100, I'm a bit confused as to how these negative values were generated. I would like to better comprehend the scoring in this variable for use, but don't understand how the range falls so negatively outside of 0-100. Thank you so much!
Response posted 04/14/25 by Mike Donohue:
Negative scores are possible if they have better scores after the delay. And large negative scores are possible if the immediate score is small. Percent forgetting is probably not a good index for cognitively healthy individuals.
