HRS/HCAP Dementia Algorithm with Cognition Cuts at 35

Abstract and overall results

The dementia algorithm cutting cognitive scores at “35”.

A threshold of 35 means that a person is counted as being impaired on a domain if the standardized and normalized score is less than or equal to 35 on a T score metric.

Introduction

As a reminder, our algorithm looks like this:

An important improvement to our data imputation step is included in this report. In our first run through the development of the HRS/HCAP diagnosis algorithm, Rich imputed impairment ratings (impaired or not 1/0) for the various cognitive domains. On the very good suggestion of David Weir, the procedure now imputes missing cognitive performance score variable (normalized, standardized) and then makes cuts to identify persons with impairment. Also, a fixed seed has been added to the procedure so that it is replicable.

Results

Unweighted distribution of final classifications (35 cut)

     hcapdx │      Freq.     Percent        Cum.
────────────┼───────────────────────────────────
   1-normal │      2,269       64.90       64.90
      2-mci │        846       24.20       89.10
 3-dementia │        381       10.90      100.00
────────────┼───────────────────────────────────
      Total │      3,496      100.00

Weighted distribution of final classifications (35 cut)

     hcapdx │      Freq.     Percent        Cum.
────────────┼───────────────────────────────────
   1-normal │ 33,945,439       67.71       67.71
      2-mci │ 11,319,539       22.58       90.29
 3-dementia │  4,867,693        9.71      100.00
────────────┼───────────────────────────────────
      Total │ 50,132,671      100.00

Weighted distribution of final classifications by race/ethnicity group (35 cut)

┌───────────────────┐
│ Key               │
├───────────────────┤
│     frequency     │
│ column percentage │
└───────────────────┘

           │             racecat3
    hcapdx │     white      Black   Hispanic │     Total
───────────┼─────────────────────────────────┼──────────
  1-normal │28,612,874  2,919,065  2,413,500 │33,945,439 
           │     68.86      63.35      60.79 │     67.71 
───────────┼─────────────────────────────────┼──────────
     2-mci │ 9,026,217  1,130,185  1,163,137 │11,319,539 
           │     21.72      24.53      29.30 │     22.58 
───────────┼─────────────────────────────────┼──────────
3-dementia │ 3,915,497    558,429    393,767 │ 4,867,693 
           │      9.42      12.12       9.92 │      9.71 
───────────┼─────────────────────────────────┼──────────
     Total │41,554,588  4,607,679  3,970,404 │50,132,671 
           │    100.00     100.00     100.00 │    100.00 

(fin)