Inflammation and Immune System Activation in Aging: A Mathematical Approach

Nikas, Jason B.

The cut-off score of the F 1 was determined by taking into account the results of the following two analyses: 1) calculation of the optimal point on the ROC curve based on the 29 F 1 scores of the 29 subjects used in the development phase [optimal point is defined as the point with the highest sensitivity and the lowest false positive rate (1specificity)] and 2) calculation of the 99.99% confidence intervals for the mean F 1 scores of the two groups (O and Y) of those 29 subjects and their respective standard deviations. The 99.99% confidence intervals were calculated based on a bootstrap sample size of 100,000. Taking into account the aforementioned ROC optimal point, as well as the relative overlap of MO and MY [MO 5 LLO -SDO and MY 5 ULY 1 SDY] (LLO: the 99.99% confidence lower limit for the mean of the O group; SDO: standard deviation of the O group; ULY: the 99.99% confidence upper limit for the mean of the Y group; SDY: standard deviation of the Y group), the cut-off score of the F 1 super variable was determined to be 53.450. If a subject's F 1 score is , 53.450, then that subject is classified as Y (young); otherwise, if the F 1 score is $ 53.450, then that subject is classified as O (old). It should be pointed out here that, based on the equation of the F 1 ( Supplementary Fig. 1 ), a given F 1 score is just a numerical value and does not signify age or number of years.