Dear all,

I try to part a continous variable in categories using the 50% CI for age groups.

Literture ref: "The alternative cut-off method defines as ‘fit for their age’ those with a FI below the lower 50% CI for the regression. ‘Frail for their age’ are those with FI above the upper 50% CI. The rest are ‘average for their age’." * (FI = value on the Frailty-Index)


For that i built age-categories (10yrs.) to define the "for their age"-part.
But i have no idea how to proceed from here.

I would be very thankful for any hint to what to look for or where!



*(Romero-Ortuno, R. (2013): An alternative method for Frailty Index cut-off points to define frailty categories. In: European geriatric medicine (5). https://www.ncbi.nlm.nih.gov/pmc/art...ihms519821.pdf)