IADL and IQCode Imputation

Documentation for imputation process of both the Instrumental Activities of Daily Living (IADL) and Informant Questionnaire of Cognitive Decline in the Elderly (IQCode) total scores in the WRAP data freeze

Starting in May 2025, the WRAP data freeze the IADL and IQCode tables will include imputed total scores and indicator columns.

Out of the 8 items in the IADL and 16 in the IQCode, total score imputing will only occur when half or fewer (IADL: 4, IQCode: 8) of the items are missing. Indicator variables will be included to help researchers identify these imputed total scores. No missing individual items will be overwritten - only the total score.

Imputation Method:

The mean value of non-missing items is calculated, rounded to the nearest whole number, and applied to all missing items. The total score is then calculated including these mean value items. If more than half of the items are missing, the total score will be NULL.


Document History

Version Date Change Reason Primary Author
May 6, 2025 Original  Rachel Studer, Dan Plotz


Keywords:
WRAP, informant questionnaire, IADL, IQCode
Doc ID:
150310
Owned by:
Rachel S. in Wisconsin Alzheimer’s Program
Created:
2025-05-06
Updated:
2025-06-10
Sites:
Wisconsin Alzheimer’s Program